Collection of Ron Mowrey articles: "Myths in B&W Photography"

larrydressler · August 7, 2009

Updating and bumping this excellent series of articles by Ron Mowrey. -- LJ, 12/12/13

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<h1>Myths in B&W photography #1</h1>

<a href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a href="../member-status-icons"><img title="Hero" src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" alt="" title="Hero" /> <img title="Subscriber" src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" alt="" title="Subscriber" /> </a> , Aug 06, 2009; 02:45 p.m.

Well, here we go with a new series of myths. This time, I will be concentrating on B&W questions that have come up over the years. This kickoff post is #1 in the list.

#1. You cannot use a stop bath when processing film or paper. It causes pinholes. Fact: You can use a stop bath. It was reported in a book by Eaton of EK years ago that pinholes might result when processing film, but this was in regard to films of the time (early 50s) and involved Carbonate developers and deep tank processing.

It seems that films of that day and age, when run through a Carbonate developer and when using a deep tank processor with a stop bath, could explosively release Carbon Dioxide gas as the film or paper rose out of the deep stop bath tank. This release of gas from these older, more poorly hardened films led to the formation of occasional pinholes. In that same era, tray and tank processed films and papers had no problem, only deep tank machine processes.

So, the problem was not generally present for most people, and today it is virtually impossible to cause it with modern films which are very hard. Mainstream films and papers from Fuji, Ilford and Kodak are much harder than the films of the 50s. There may still be films and papers made today using old formulas, so you may wish to test this out if you are using products from other companies.

However, those of you that prefer to use a water rinse after the developer instead of a stop bath must be aware of a problem. If you use a neutral fix or an alkaline fix, you run the risk of staining the print or negative unless you use running water for the rinse. The reason is that developer gradually builds up in a static rinse bath and this eliminates the utility of the rinse, and also exhausts the fix bath more rapidly.

So, you can have pinholes from any process type, but they are not generated by the stop bath, at least in properly hardened films and papers and if you use common darkroom equipment. You may even hear FB papers fizz when you go into the stop bath, but pay no attention. It is doing no harm to your print.

Ron Mowrey

<h1>Myths in B&W photography #2</h1>

<a href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a href="../member-status-icons"><img title="Hero" src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" alt="" title="Hero" /> <img title="Subscriber" src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" alt="" title="Subscriber" /> </a> , Aug 06, 2009; 02:55 p.m.

Myth #2: You can use household detergent in place of Photo Flo or the equivalent to prevent water spots. Well, yes and no. Yes you can if the detergent meets the followng criteria: a: It contains to dye to tint it. It must be clear b: It contains no scent c: It is a liquid itself when the water is evaporated off d: This is optional - If it is non-ionic

Ok, here is the problem. Most detergents dry to a scummy solid with an odor and a color. This can ruin your negatives. In hard water areas, ionic surfactants (soaps) can form salts with the metals in hard water such as Calcium, and leave a scum. Photo Flo and many other detergents are non-ionic, or are formulated to form no precipitate when they dry down in the presence of metals in hard water.

Good wetting agents also do not dry to a solid or near solid, but rather either remain a faint trace oil in the emulsion or they slowly evaporate as the coating dries.

Some advocate the use of alcohol as a final rinse. This can be done, but remember that alcohol was used to assist in rapid drying, not as a wetting agent, and also denature alcohol sometimes contains ingredients harmful to film. One type of denatured alcohol forms a fine white precipitate when mixed with water, and this can cause a haze to form in the film.

Ron Mowrey

<h1>Myths in B&W Photography #3</h1>

<a href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a href="../member-status-icons"><img title="Hero" src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" alt="" title="Hero" /> <img title="Subscriber" src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" alt="" title="Subscriber" /> </a> , Aug 07, 2009; 10:02 a.m.

#3: You should use an acid / alkaline / neutral fix for B&W. It should be Sodium Hypo based / Ammonium Hypo based / Something else.....

Well, all of the above are possible.

Any Sodium or Ammonium Hypo based fixer is usable with B&W films and papers as long as the pH remains between 4.5 and 9.0. However, to have a hardening fix, the pH must be in the lower range, about 4.5 or the hardener will precipitate. At this pH, the fix will have a strong odor of SO2 and Acetic Acid, and will be less stable to decomposition. Wash times will be long due to the fact that a low pH causes gelatin to swell far less than when the gelatin is neutral or acid.

At a pH of 8 - 9, gelatin swell is at its maximum and therefore fix times are shorter and wash times are shorter. Stability is greatest and decomposition of the fix is slow. What you sacrifice is the capacity of the fix unless you use a stop or running water rinse after the developer. And yes, you can use a stop bath before an alkaline fix. This is provided the fix is buffered properly. Usually, you can tell this is so if the fix concentrate has some sediment in it before diluting with water. This is precipitated buffer. This type of fix will gradually release ammonia gas during use and may be a bother to some people.

At a pH of 5 - 7, you make a compromise of all features. Swell is medium, fix rate is medium unless some chemical adjustment is made to the fix and wash times are medium unless something is done to accelerate the wash rate. This is a compromise fix.

Sodium based fixes are slow, but Ammonium based fixes are fast and are the basic foundation of all rapid fixes on the market. Sodium and Ammonium ions are the only two positive ions that should be added to a fix bath. For example, both Mees and Haist cite the fact that Potassium ion will just about poison a fix and Calcium and Magnesium ions will slow a fix down drastically.

For any fix, a manufacturer cannot give you a true wash time or capacity. You should test your fix and wash for suitability using the standard retained hypo test, retained silver test and the hypo exhaustion test. The latter is the most subjective and hard to interpret, but basically once you have this established you should be in a good position.

Ron Mowrey

<h1>Myths in B&W photography #4</h1>

<a href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a href="../member-status-icons"><img title="Hero" src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" alt="" title="Hero" /> <img title="Subscriber" src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" alt="" title="Subscriber" /> </a> , Aug 07, 2009; 10:12 a.m.

#4: Divided developers are great / ok / no good

All of the above are possible.

Consider this.... Each film has a different amount of silver halide and a different amount of gelatin. Not all films are hardened the same. So, the content and swell varies from film to film. A divided developer functions by absorbing enough of part A to do the job of development when the soaked and swollen film is placed into part B.

Here is where the problem comes in. Due to the different amounts of A that different films absorb, the extent to which B can do its job varies in proportion. Let us imagine a thick film that swells a lot and a thin hard film that does not. If you place both of them into part A, the thin hard film may be actually starved for solution, but the thick film may have an excess. In part B, the thin hard film will probably be underdeveloped.

Thefefore, the divided developer and the process conditions (time in A and time in B) must be adjusted for each film or the optimum results will not be obtained. Customizing a divided developer is a very painstaking job and can become quite expensive. The results are very good when optimized, but can be very poor if not optimized. The bottom line is that you should not use the same conditions for every type of film!

Ron Mowrey

lex_jenkins · August 7, 2009

Thanks, Larry. I've made these threads sticky so they'll remain at the top of the queue for a week or so, but only via the main forum page (not the unified forum view). I'll also attach links elsewhere on the b&w forum to make them easier to reference in future.

BTW, I'll change the title of this thread to make it a bit less confusing. The original title, "Collection of Myths so far By Ron" might be misinterpreted by some readers.

keith_tapscott · August 7, 2009

Lex, I am glad you have made Ron`s B&W Photo-Myths `sticky`s`.

larrydressler · August 16, 2009

<h1>Myths in B&W photography #5</h1>

<a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 07, 2009; 07:51 p.m. #5: Old developers are not usable with modern film emulsions / new developers are not usable with old film emulsions etc.. This long standing argument is based on a lot of though by a lot of people. It will be linked loosely to the next myth. The answer is a yes and no both. Or maybe an it depends! One venerable old formula is D-76. It was used (and probably still is) for release testing of all Kodak B&W films. So, at the last I knew, it was the benchmark for films made by EK world-wide. Basically it is an MQ (Metol - Hydroquinone) developer and several minor variants exist. XTOL and Microdol X are other developers that come to mind that are commonly used on modern day films and Microdol and Microdol X were used back in the 60s. So, what is the complaint? What is the problem? Well, recently I have been looking over some formulas and patents and I see that HC-110 (released in the late 60s) is also a modern developer that is quite different than any other developer released up to that time. It is a mix of DEA and TEA (Diethanol Amine and Triethanol Amine) to get the proper solvent ratio. Then this is mixed with Sulfur Dioxide gas and Hydrobromic Acid gas to supply sulfite and bromide (as salts of the DEA and TEA) and then the developing agents are added. This unique developer then has a balanced silver halide solvent in it and it has, at the same time, low Sodium and Potassium content and virtually no water. Therefore, the syrup lasts a long, long time! It also works with virtually all films. This is truly a modern developer and uses unique chemistry, but it works just fine with many films made by other manufacturers that use older emulsion formulas. Take a look here: <a rel="nofollow" href="http://www.kodak.com/global/en/professional/products/chemistry/bwFilmProcessing/selecting.jhtml?pq-path=14053" target="_blank">http://www.kodak.com/global/en/professional/products/chemistry/bwFilmProcessing/selecting.jhtml?pq-path=14053</a> This chart by Kodak shows developers rated by speed, grain and sharpness, the three criteria that are related to developers. Normally you can only max out 2 of them at one time. This chart shows how six current Kodak developers respond. When you use any film and compare it with these developers, the relative positions on this chart may change, but the developers will still work. Amazingly, old formulations still work with modern films and new formulations still work with older emulsions. It is just a matter of finding a sweet spot with your film / developer combination. You only have two things to choose from, film and developer, so it can't be too hard.... Well, ok, I have given some insight, but there must be more to it or people would not be asking questions and raising this myth flag, so here are some of the problems: 1. There are multiple "so called" approximations to popular formulas such as D-23 + NaCl instead of Microdol X. Believe me, this is not Microdol X and may not work due to missing a key ingredient that prevents Dichroic Fog. If you use a modern film, this may not be a problem, but with older emulsion formulas it may be. 2. I have 3 formulas for one developer just looking at the Metric system. If you include the English system version and the Imperial system version there are over 6 formulas for one developer spread across more than 6 textbooks. I personally have 6 of those formulas here with errors either in calculation or transcription. So, some variations in results may be due to errors in printed, do it yourself formulas. I estimate that perhaps 50% of the printed formulas have some sort of error. How this influences the creation of this myth IDK. I just mention it. 3. Some people use home mixed developers using grocery store chemistry and volumetric measurements (teaspoons of Sodium Carbonate?). This can be done, but I can demonstrate that there can be as much as a 20% error in such work. There will be another "myth" on this as well. 4. Some people use staining developers or simple PC/TEA developers. These formulas do react differently with modern films in some cases, but then they react in a different matter with older emulsions. So, having seen few comparisons, I cannot say if it is good or bad, but this may be the source of the myth. A given "simple" PC/TEA formula may appear to work wonderfully with a new developer and get a great reputation with no direct comparison to HC-110 or XTOL or even D-76. Here we may have some meat to flesh out the myth. Until this work is done, we won't know. 5. HA (High Acutance) developers may not work with modern films. Many, such as the Windisch developers, use a small amount of KI (Potassium Iodide) added to them to increase edge effects. Old films had buried Iodide and this surface addition of Iodide happened so fast that development, when started, began to release Iodide as a function of development and therefore caused edge effects. Modern film emulsions contain Iodide, either in the core, graded in the shell or on the surface. Therefore, addition of Iodide can either have the "normal" effect, no effect or a negative effect depending on the type of the emulsion they are trying to develop. This is a real case where an older style HA developer may have a varying effect on old and new emulsion types. It is also a case where we cannot tell in advance, and must test. So, this "myth" appears to have some basis in fact. Bear it in mind when choosing film and developer. And, remember that you can only really get 2 out of three of the desired characteristics out of a developer, and therefore there is no magic bullet. Ron Mowrey

<h2>Answers</h2>

<a rel="nofollow" href="../photodb/user?user_id=740891">Alan Johnson</a> , Aug 08, 2009; 08:53 a.m. I cannot find anywhere reference to a high acutance Windisch developer containing potassium iodide and wonder if reference to Crawley's FX-1 was intended. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 08, 2009; 10:05 a.m. Alan; So sorry, that is my error. It is indeed the Crawley developer. My head is packed with too many developer formulas lately as a result of studying formulas for these posts. Thank you for the correction! Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=391082">Jordan W.</a> , Aug 08, 2009; 10:34 p.m. Ron, I've hear this "myth" before, too, and I'm not sure where it comes from. It would be interesting to trace it to its origins. My suspicion is that it is tied to the advent of TMAX and other new-technology films -- they presented something of a learning curve and maybe it was just easier to blame the developer when things went wrong. I think the you-mix-it crowd is both too small and too savvy to be the driving force behind the idea that there are universal incompatibilities between old / new developers and new / old films -- while hobbyist scratch-mixed developers have their issues, I've never seen anyone make blanket statements about their insuitability for any particular type of film. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 08, 2009; 10:54 p.m. Jordan; The films made today by Kodak, Fuji and Ilford are different, and there is no doubt about it. The curves shapes are different as well (to some extent). So, there is some difference, but to me, I get good results from HC-110 and D-76 as long as I center the image on the curve or as long as I overexpose slightly. Having worked on Gold 400, I can say that I appreciate having to design what I described above in my previous post. It is not easy, but it does produce some beautful photos. The You-mix-it people may be using formulas that are incorrect, as I point out. I have seen two formulas where pyro and sulfite weights are reversed. They both work but in a diferent way and with different results. All of this variation out there lends some slight but real credibility to this myth and I don't want to dismiss it lightly. Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=215867">Thomas Sullivan</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/2rolls.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 09, 2009; 02:44 a.m. all I know, after developing film since 1975, HC-110 rules! It gives a great negative for almost every film I've developed it in. <a rel="nofollow" href="../photodb/user?user_id=740891">Alan Johnson</a> , Aug 09, 2009; 06:19 a.m. Ron, "Old films......began to release iodide as a function of development and therefore caused edge effects." I thought iodide is a restrainer of development.But the edge effects (Mackie lines) are caused by more development.Can you explain in more detail how the iodide might cause extra edge effect (Most of the edge effect comes from the lateral diffusion of metol and is not dependent on the presence of iodide)? Thanks <a rel="nofollow" href="../photodb/user?user_id=829026">Larry Dressler</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/3rolls.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 09, 2009; 06:39 a.m. I have used Rodinal 1-100 with Delta 100 and it was beautiful. I did a 50 minute stand... But I will say that HC-110 and Diafine are the 2 I use the most with many films.. Is Diafine a new or old developer as the Old Panthermic developer that The Catchet AB-55 seems to be a clone of even to the point of replenishment. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 09, 2009; 09:25 a.m. Larry, if you get good results that is all that matters. Alan, edge effects follow a very complex pattern and depend in size. In fact, they determine macro and micro contrast. See the attached traces of density vs distance across a line. Photos courtesy of Mike Kriss of Eastman Kodak. Ron Mowrey <img src="http://static.photo.net/attachments/bboard/00U/00UATt-163305584.jpg" border="0" alt="" hspace="5" vspace="10" width="522" align="BOTTOM" /> Edge effect density vs distance in microns <a rel="nofollow" href="../photodb/user?user_id=740891">Alan Johnson</a> , Aug 09, 2009; 10:11 a.m. Ron, Crawley (BJP Jan 6 1961) suggested "The presence of iodide ion may just enfeeble the developing agency and predispose it to produce adjacency effects." My take on this is that he may have meant the adsorbed iodide acts as a restrainer and slows development down,which would allow more time for lateral diffusion of developer and of oxidation products,thereby increasing edge effects. This seems to be consistent with your explanation in 5HA.The iodide effect makes good mythology. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 09, 2009; 10:45 a.m. Alan; Any way you look at it, emulsions of the 20s - 40s were about 0.3% - 3.0% iodide (average generalization) but today can go as high as 10%. Older emulsions were either buried or uniform in iodide distribution (being Single Run or Single Run Ammonia Digest - SR or SRAD). Modern emulsions are double run (RS - Run Salts) and the Iodide can be placed anywhere at will. This drastic change will influence the way Iodide reacts if added to the developer. So, I remain of the opinion that there can be some substance to this myth, depending on emulsion and developer. Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=4450385">Drew Simons</a> , Aug 09, 2009; 08:06 p.m. Thanks for posting all of that insightful research Rowland. In the limited testing that I have done, I did find that TMAX developer was a disappointment with TRI-X. The images were flat and the grain didn't pop out compared to D76 or especially Rodinal. However, I realize that some people find these flatter images better for the eye, so I guess it is a case of whatever suits.

<h1>Myths in B&W photography #6</h1>

<a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 07, 2009; 08:07 p.m. #6: Silver rich films and papers are better than modern films and papers that use lower silver. This is an out and out myth! In the early days of photography, emulsion making was a very imprecise science and led to emulsions in which there were a lot of what we called "Dead Grains". They were either insensitive to light or just would not develop. So, in order to get the right contrast or Dmax in a photoproduct, a high level of silver had to be coated. To achieve a density of 3.0 in a film may have taken 500 mg of coated Silver per unit area, 100 years ago, and today only 300 mg of silver per unit area. But, in both the old and new film, only 300 mg of silver per unit area is being developed. You see, a density of 3.0 can be related to an exact amount of real silver metal (taking into account the form of the silver that the developer creates). The benefit in older emulsions comes from packing the Silver halide crystals tightly to give fine grain. Well, this is good, but today, the same grain can be achieved by making smaller crystals with better senstitivity. So, this evens out. In fact, we come out better with modern, finer grained films with lower silver. The modern films are less turbid and therefore are sharper! So we get the same grain today at higher speed and with greater sharpness all other things being equal, and we can use less silver halide per unit area. Just keep in mind that the amount of Silver metal that forms the image is likely the same or nearly the same in both the Silver rich and low Silver products. Now, lets think back to myth #5 regarding old and modern developers. Here is a case where there may be another item to support myth #5 as being potentially a true fact. Old, silver rich films and papers will react differently in some of the old developers due to the fact that they were often designed with higher energy to try to push the dead grains into activity without fogging the product. I have no specific cases for this latter to offer you, but merely present it as a possible special case! Ron Mowrey

<h2>Answers</h2>

<a rel="nofollow" href="../photodb/user?user_id=561875">Jonathan -</a> , Aug 08, 2009; 06:59 p.m. Ron, modern films seem to have an edge (pun intended) in terms of grain size, speed and sharpness. On the other hand, they seem to require greater precision in exposure and development. Assuming my premise is correct, would you care to comment on the relationship, if any, between technical superiority and process sensitivity? <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 08, 2009; 07:38 p.m. I'll have to make this a generalization. Most older films (not all) achieved a long tone scale by virtue of the fact that they were made from polydisperse emulsions. This means that you have a large difference in size from the small to large grains within that emulsion and they give you lots of latitude but also give you curves that bow upwards, sag downwards and generally have soft toes and shoulders. This sag and bow are bad for mid tones, but the soft toe and shoulder give you lots of over and under exposure latitude. If you got a straight line mid scale, you really had a good film, but it was hard to do. The real winners had the desired toe, shoulder and a straight line mid scale. Most modern films use blends of as many as 3 emulsions, each one of which represents a speed region of that film. They are rather monodisperse, but give sharper toes and straight line mid scales. They can be built to have a very very long shoulder. So, today's films have less underexposure latitude due to the toe, and more overexposure latitude while the mid scales don't suffer at all. However, errors in processing can cause the overlap points between emulsions to form mismatches and give a small bump at the join. So, you do have to be careful about processing and underexposure in my opinion. Now, to specifics, the modern films contain a fast, medium and slow component. For a 400 speed film, the fast may be 800, the mid 400 and the slow 200. This blend forms the entire curve and there may be some 100 in there to extend the shoulder (a 4th component if you will or some excess slow 200 to extend the shoulder). In fact, due to turbidity, there are acutance dyes in the films to sharpen them up and prevent light scatter. That is the colored dye you see in the prewet or developer. This means though that in a 400 film, the actual components may be 900, 500 and 300 due to the speed trimming effects of the acutance dye. It also allows some high speed leeway so that every batch of film is exactly trimmed to 400 speed. So, there it is in a nutshell and a generalization. I hope this helps. Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=561875">Jonathan -</a> , Aug 09, 2009; 07:13 p.m. Thanks, Ron. That does indeed help. <a rel="nofollow" href="../photodb/user?user_id=705780">Stephen S</a> , Aug 10, 2009; 08:53 p.m. Rowland, any comment on the (supposedly high-silver content) Efke films? <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 10, 2009; 10:25 p.m. They are older emulsion formulas, AFAIK, and thus may need more Silver halide to be coated to achieve a given density. Or, they may be high by design. IDK. Kodak, Fuji and Ilford use the amount of silver needed to achieve a given density. Ron Mowrey

<h1>Myths in B&W photography #7</h1>

<a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 09, 2009; 06:52 p.m. #7: You can mix a partical bag or kit of dry developer or fix. No, you cannot. Kodak's own web site cautions against this due to uniformity problems. This is a total myth, and a dangerous one if you wish high quality negatives and prints. Dry kits such as Dektol are made under an inert atmostphere and packed the same way. The "part a" and "part b" ingredients are made in separate operations and then blended after each part is coated with a material which insulates them each from the other and so the developer is protected from the alkali in the final mixture. This mixture is not homogeneous because just like shaking a bag of different sized and shaped stones, some separate to the top and some go to the bottom. So, using the whole package will get what you deserve to get, but using part of the bag will give you a nonuniform portion of the mix every time you take out a scoop of the contents. And besides, it exposes the bag or container to contamination by air. So, if you have a 1 gallon or 4 liter bag of Dektol, it is best to mix it all at once and store it in 4 smaller containers, then blanket it with intert gas. Stored this way, it may keep for up to 6 months as opposed to a partially full bottle with no blanket of inert gas which might keep for 2 - 6 weeks. As an added note, D-52 and Dektol are identical, AFAIK except for 2 things. Dektol contains a sequestering agent to prevent scum or turbidity in hard water, and the particles are coated with an inert substance that dissolves in water but keeps the ingredients separated during dry storage. This is pretty much the same for all Kodak prepackaged developers and the published formulas. Ron Mowrey

<h2>Answers</h2>

<a rel="nofollow" href="../photodb/user?user_id=2147789">Ian Tindale</a> , Aug 09, 2009; 07:42 p.m. What on earth are you supposed to do with those bags of dry particles then if you can't mix them? <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 09, 2009; 07:52 p.m. You mix according to instructions. You mix the entire bag of dry particles into the correct amount of water and dissolve, then dilute to the value in the instructions to make the stock solution. In the case of Dektol, you start with about 3 quarts of warm water or 3 L of warm water, dissolve the materials in the bag. Add water to 4 quarts or 3.8 L and you have Dektol stock which is then usually used by diluting 1:2. But, you never weigh out 1/4th of the bag of solids and try to make 1 quart of developer. It will not work properly. Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=2321611">Alec Myers</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 09, 2009; 08:16 p.m. I have to say, theory aside, I've been using a bag of powdered D76 for the last year made up to solution in bit-by-bit (clearly I develop a lot of films!) and I've had good uniformity. Perhaps I just got lucky. <a rel="nofollow" href="../photodb/user?user_id=79798">Frank Schifano</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 09, 2009; 09:22 p.m. How do you know that's true? You can't always tell with complete certainty by examining negatives. There are simply too many variables from roll to roll to make that assumption. However, if you tell me that you are developing control strips exactly the same way with the batch of developer being the only variable, then I'd be inclined to believe you. <a rel="nofollow" href="../photodb/user?user_id=19814">Jim MacKenzie</a> , Aug 09, 2009; 10:11 p.m. Alec, if you don't want to mix up a full US gallon of D76 at a time, buy the bulk ingredients (metol, hydroquinone, sodium sulfite and borax) and make up as little or as much as you like at a time. <a rel="nofollow" href="../photodb/user?user_id=589033">Walter Degroot</a> , Aug 09, 2009; 10:43 p.m. I consider you an expert who really know what he is saying. however, there was an old 1972? article in Camera 35 entitled " spoon up a savings" it describes how to make up whatever quantity of developer you need with measuring spoons. I do not have the name of the author. and he supports his concept with tests and examples. I see your point. it is logical and makes sense. you are in a position to know about this. <a rel="nofollow" href="../photodb/user?user_id=4260916">Jason Hall</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub2.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 09, 2009; 11:02 p.m. Walter....just read this..... <a rel="nofollow" href="http://www.apug.org/forums/forum37/65010-teaspoon-measuring.html" target="_blank">http://www.apug.org/forums/forum37/65010-teaspoon-measuring.html</a> Jason <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 10, 2009; 12:38 p.m. Teaspoon measuring will be one of the topics I cover. It can be quite inaccurate, but can work for some solutions with reasonable confidence. Stay tuned. As for using part of a dry kit from any company, the guideline I gave above comes directly from Kodak, posted on their web page in the chemicals section. It has been tested at many facilities and shown to be an unreliable method, but it will work sometimes or at least appear to work, but without a check to compare to you may not see any problem. If your film is 1/3 stop off, or off in contrast by a bit, you may not see it in a single observation without a comparison, and as one person pointed out, in a paper developer, you might have compensated during development by adding a few seconds to development time to get a good print. Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=2321611">Alec Myers</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="78" align="BOTTOM" /> </a> , Aug 10, 2009; 08:34 p.m.

Ron, of course you're quite right - I have no idea if it's exactly true. But I have nicely developed negatives, regardless. Jim - Yes, I looked sourcing the raw chemicals, but they're quite expensive in sensible quantities here in the UK. It's not a huge monetary loss to make up the full gallon and discard after a while; alternatively, Kodak do sachets to make up 1 Litre of developer at only a very small pro-rata price hike over the Gallon packets. Which I think is my preferred way forwards at present. <a rel="nofollow" href="../photodb/user?user_id=589033">Walter Degroot</a> , Aug 10, 2009; 11:04 p.m. when I worked Ohas I was considering making up my own developers I purchjased a triple beam and a cent-o-gram capapbe of less that 0.1 gram. or less. I was warned by "scalemen" not to get the model with a calibrated dial. I have a copy of "spoon up a savings" in pdf format, there was an outfit that had kits to make up many B&W developers and even e-4 solutions WITH SPOONS. never tried it. <a rel="nofollow" href="../photodb/user?user_id=1500304">john robison</a> , Aug 11, 2009; 07:30 p.m. That's why I like HC-110. Mix up a one shot and discard. For paper developer I emptied and rinsed out a 5L box-o-wine and mixed a gallon size of Dektol for it. The solution still seems to be good after two years, no sign of oxidation yet. After drinking all that very forgetable merlot I was surprised I could still see the mixing instructions on the package.

<h1>Myths in B&W photography #8</h1>

<a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 10, 2009; 08:25 p.m. Well, here goes a myth with a huge controversy raging over it. There are two very controversial myths already planned in this series. #8: You can use tablespoons, cups, teaspoons and other measuring devices to measure out solids for the preparation of photographic solutions. Fact: Maybe, or it depends. I can take a cup of Sodium Thiosulfate pentahydrate and a pinch of Sodium Sulfite and dissolve them in 4 liters of water to make a very good fix. I cannot give you accurate fix times, nor can I predict wash times except to say that they will be long. But, it will work. And, I would never use that cup again for food measure to be on the safe side. So, here is a basic guideline... Preparation of solutions that go to completion are most likely able to be prepared by taking a cup or spoon full of chemistry. This includes Stop Baths, Fixers, Bleaches and Clearing Baths. Of course, you are on your own as to time needed to carry out the function intended. AND.... with each batch of chemistry you will have to retune your process due to another variable. Lets look at Sodium hypo. It comes as a rice like material and has a fixed density. If I grind it to powder, it is the same density, but it has a different packing density. So, a cupful is hard to measure to start with because you have trouble rounding off the cup due to the rice like nature of the hypo. If you grind it to a powder, you have more hypo in the cup but you can round it more easily. These two cups full of hypo will contain a different amount of hypo and the resultant fixes will have different activities. The same is true of KBr (Potassium Bromide). I have two batches that came from the dealer in different form. One is a fine powder and the other is a large cubic crystal. When I tried to measure 2.0 grams of KBr from these two samples, I got 1.8 grams in one case and 2.2 grams in another. This variation was due to the packing density and the ability (or non-ability) to round off the spoon. I made many such measurements from 1 g - 2 g simulating the making of Dektol type developers (1.5 g/l of KBr). Well, you can do it, but this variability will give you different speeds and contrasts as well as development rates. If it were the Kodalk or Carbonate, then the pH would vary leading to contrast variations as well. Lets go to a film developer.... In this case, you may be looking at D-76 which if measured volumetrically may have from 90 - 110 g/l of Sodium Sulfite instead of the desired 100 g/l. This sulfite is present to control grain and sharpness. In either of these examples were to happen with no checks and balances, then you might say things are fine, but you might, in the long run, wonder why your prints were more contrasty or your negatives were grainier than another person achieved using the same film, paper and developer. Here might be your reason. Scales and balances are inexpensive. Weighing takes a bit more time. Cup and teaspoon measurements are quick and "dirty" and you may have to make several trials to fine tune your spoons taking some time and material. But, if you can accept the fact that you are not getting the very best then if it works, use the method. I don't, nor does anyone else I know who is a serious photographer. Some have pointed to reloading shells with gunpowder as a reliable method of using volumetric measure. I accept that, but point out that a reloader will cut grains giving you a fraction of a grain with no rounding error you get by scraping the surface of a rough powder flat on a teaspoon. If you use a powder dispenser, they are more accurate but are still limited especially if the material varies in form from batch to batch. Many Kodak formulas you get are already rounded up or down as needed and so further drift from the actual formula may not be a good idea. The weights given should be read as given and so 3 grams means 3.0 grams. Ron Mowrey

<h2>Answers</h2>

<a rel="nofollow" href="../photodb/user?user_id=4638208">Janne Moren</a> , Aug 10, 2009; 11:09 p.m. As someone who bakes bread as a hobby I can say that weighing actually takes less time than fiddling with volume measurements. What you need is an electronic scale that you can tare as needed (they're quite cheap). Put the empty container on the scale and zero it. Pour the first ingredient to the correct weight, then zero the scale again. Do each ingredient the same way. Compared to playing with measuring cups (trying to get each ingredient ot the bowl with no spilling, making sure you're actually getting all of it out of the cup, having to wash the measuring cup or spoon between each ingredient), weighing is faster, easier and more accurate. <a rel="nofollow" href="../photodb/user?user_id=4260916">Jason Hall</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub2.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 10, 2009; 11:22 p.m. Any reloader who is concerned with repeatable accuracy, will weigh ever powder charge before loading in the casing. When folks use reloaders that measure the powder charge by volume are concerned with speed of production and quantity. Accuracy is secondary. On the other hand for some a 2" group at 100 meters is "paydirt". For others, it was a waste of perfectly good lead. Neither is wrong, it only matters if the result meets their expectation. (back to film development) One notable difference I have noticed with the folks that tend to measure by volume(again, not saying right or wrong), is that they cite they get "Useable" or "printable" negatives. For many that is perfectly acceptable and all that is expected. I am new to this, but it makes me uneasy. There is a reason shooters measure their accuracy with three round groups. To hit the same mark with two shots could be luck, to do it with the third shot...that is skill. Reminds me of the folks that were tickled with a 2" group @ 100m (most were not that good, I am being nice here), who can be quoted as saying "I can hit a deer with that". Where will they hit it? Who knows, but with one of the 300 magnums on the market, it really didn't matter.....did it? Just not my style I rekon. I am pretty darn new to film developing, so what do I know? To be honest, I'm not sure. Just some thoughts that come to mind after reading a thread on a related subject else where. Jason <a rel="nofollow" href="../photodb/user?user_id=448865">Edward Zimmermann</a> , Aug 11, 2009; 04:09 p.m. Scales and balances too don't always work--- and I'm even including analytical lab scales readable and accurate to fractional mg (mine has a precision of a 0.01 mg) --- and one is often best off working with concentrations and then using volumetric measurements. In most chemistries--- especially photo--- it does not matter but it can matter .... Now in the real photographic world.. people tend not to have analytic lab scales--- nor the training to use one properly. The scales they have at home, if any, are cheap but are not terribly accurate. The digital ones are especially evil as they confuse readability to accuracy.. Toss in formulas asking for 0.1g of a chemical for 1 liter and one is just looking for errors. Instead of thinking dry measures--- which can work well with some formulations and some chemicals--- or mass one needs to think about the chemicals, their function etc. Look at, for instance, Gold Chloride.. its just so horribly hygroscopic that instead of purchasing a few grams in glass tubes one is nearly always better off purchasing a bottle of a known solution (such as 1%).

<h1>Myths in B&W photography #9</h1>

<a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 12:52 p.m. Well, here goes with another controversial item. #9: You can use grocery store or pool store chemistry for making up photographic solutions. Fact: Yes and no, with a lot of warning flags to be aware of. At your pool store, you can get Sodium Thiosulfate and Sodium Sulfite as well as Sodium Carbonate. These are used to control the chlorine level and pH of swimming pools. At the grocery store, you can get detergents, Borax, Sodium Carbonate and Sodium Bicarbonate for washing and baking. These are commonly used in fixers and developers. Here is where I must raise the warning flags. Often, the tub or box that these chemicals are in state 95% pure or 98% pure. This is the problem. What is the other 2 - 5%? Most of these bulk chemicals are dug from evaporated lake beds scattered across the world. It is not uncommon to have other salts incorporated into them. Therefore, you will not get the pH you expect from impure Sodium Carbonate and the impurity might be a mix of sea salts such as NaBr, NaCl, KI, MgCO3 and etc... This will restrain your developer by the lower pH, buffer capacity and presence of extraneous halides. More importantly would be the presence of Calcium Carbonate, seen as a slight haze suspended in the developer or as a tiny sludge at the bottom of the container. If you try, you might or might not be able to filter it out of the solution. If you cannot, imagine this scenario. This haze, or suspension of solids in the developer is composed of small particles on the sub millimeter or large micron sizes. These particles can get into the gelatin matrix of your film and sometimes the particles do not wash out totally. Upon enlargement, you see these particles as grain or dirt in the final image. This can also happen when you make up a fixer from pool store hypo or sulfite. I suggest that if you see a haze under any of these conditions, you add a sequestering agent to see if you can get rid of it. Add about 5 g/l of Na2EDTA (Disodium EDTA) a common sequestrant. If that does not work, then the haze may be just finely ground insoluable material such as crushed rock that comes from the mining operation and which was not purified out. Remember, there are such things as photograde chemicals. There are ISO and ANSI standards for every ingredient. Some of the other things that are refined out of photograde chemicals that can harm emulsions during making or during development include salts of Lead, Mercury, Iron and other heavy metals. Also forbidden are anti caking agents such as Sodium Silicate, commonly used in household products. Scents and dyes are forbidden in photograde chemicals as they can stain or otherwise damage the emulsion. On a final note regarding myths #8 and 9, I cannot see why someone would spend good money on a camera and film and then scrimp on process chemistry and chance damaging their pictures. This has always seemed to be to be an odd mind set. Ron Mowrey

<h2>Answers</h2>

<a rel="nofollow" href="../photodb/user?user_id=1841065">JDM von Weinberg</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub4.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/3rolls.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 02:27 p.m. What a spoil sport!

<blockquote>why someone would spend good money on a camera and film and then scrimp on process chemistry and chance damaging their pictures</blockquote>

chance? CHANCE ? ------ That's the point, after all It's the joy of discovery! Like you, I can't imagine why anyone would process their professional wedding pictures in such-like muck, but I can't imagine that anyone is actually doing that. You shoot your film in your Altissa or LOMO or Holga, then you add a little spice by developing it in instant coffee and caustic soda (<a rel="nofollow" href="../black-and-white-photo-printing-finishing-forum/00TynS">link</a> ). This is not a "myth", this is "epic" adventure. ;) Besides, what good money on cameras? Many of mine cost me less than US$30, and often I am shooting on 20-year old film. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 03:35 p.m. JDM; If you wish to do that, why not use caffeineol or some such then, for a true adventure. Using teaspoons and cups is culinary, using wine, horse urine or coffee is an adventure! Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=448865">Edward Zimmermann</a> , Aug 11, 2009; 04:42 p.m. Here in Germany at some drugstores/supermarkets one can get Sodium Carbonate sicc in a reasonable purity for 1 EURO a 500g bag. The chemists shops (Apotheke) sell instead the decahydrat form. The anhydrous soda that I've purchased is absolutely suitable and no worse for the application than what I would get (but pay several times as much) from any of the chemical distributors (even if I would purchase a very large sack). Many of other basic chemicals (like Borax, Boric acid, Sodium Hydroxide, EDTA, Triton-X 100 etc.) I get from Kremer Pigments (a leading supplier of art pigments and restoration supplies). A lot of what the photo shops sell is "photographic grade" and is, despite the higher price, of lower purity. <a rel="nofollow" href="../photodb/user?user_id=79798">Frank Schifano</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 05:38 p.m. But Rowland's point is that you don't exactly know what the impurities are. They may, or may not, affect the action when used for photographic purposes. If the chemicals are "photo grade", then you can be assured that the impurities are not significant to the process. <a rel="nofollow" href="../photodb/user?user_id=1713391">Michael Axel</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub5.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/3rolls.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 06:06 p.m. Rowland,

<blockquote>I cannot see why someone would spend good money on a camera and film and then scrimp on process chemistry and chance damaging their pictures.</blockquote>

I cannot fathom the reasoning either. Not just the cost of equipment and film, but the cost to get to the subject, your knowledge and time to expose the image, etc. It doesn't say much about someone's work, either. These are very good, Rowland. Pace yourself though!<g> <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 06:25 p.m. Good points to consider in all of these comments. I have about 2 more of these in preparation, maybe more, it depends. As for chemistry, I have actually seen very very pure chemicals fail in their use in photographic solutions. The one I mentioned is the chemical that forms a cloudy solution in spite of being quite pure. The photograde version is Calcium free. In another example, an Iron impurity in an otherwise very pure sample caused black spots to form on some materials when used in photo solutions. So the real test is what is allowed in photograde. There are limits established for certain metals and heavy metals that apply here, and that is my point. It depends. These chemicals may work 90% of the time and then fail you when you least expect it. That is the unpredictable nature of this type of potential problem. And, all I'm trying to do is point out the potential pitfalls. I always say, use what works for you. But, if I have forewarned you, then please don't complain! Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=1841065">JDM von Weinberg</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub4.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/3rolls.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 11, 2009; 08:18 p.m. Raymond, you're far too serious and sober to ever be a Lomographer. ;) <a rel="nofollow" href="../photodb/user?user_id=448865">Edward Zimmermann</a> , Aug 12, 2009; 05:09 a.m. Ron but what is "Photographic" grade? I have seen little proof that there is any grading of impurities but that its nearly always just selected technical grade. A lot of the chemicals I get from non photographic supplies is the equivalent to USP grade. Sure there can be impurities that can create problems but that's why there are "Reagent" and even higher grades to be had. I have seen more than enough commercial developers fail (or lets say not behave to their intended specifications) by impurities in chemicals made and sold as photochemicals. Part of the art of creating developers is to include into the formulation fail-safety and to address things that can go wrong. Chemicals do vary from batch to batch. A good example would be the reaction of ferric ions with ascorbic acid in "VitC developers" (such as witnessed with Microdol-X to keep to "Big Yellow"). But there are more examples. I know of one company that just stopped making amateur colour chemistries because they could not source consistent colour chemicals. Merck used to supply analytic reagent grade (p.a.) CD4 but stopped their production. The Chinese stuff is "photographic" grade but at least for this application (from the perspective of the vendor) "unacceptable". "Purity" costs money but dealing with impurities too can cost money and so its a balancing act. Even major photo chemical manufacturers (Tetenal, Agfa and, as you are most familiar Kodak) need larger scale for their chemical kit production to be able to provide consistent enough quality in their concentrates. Purchasing raw chemicals from a photographic supply company is not a fail safe answer. While their kits might be reasonably well tested there is no certainty that some "impurity' won't strike in some particular application. There are, of course, other factors.. In a German photographic forum someone had sudden death with their VitC developer that was traced back to their use of glass marbles to displace oxygen--- cheap marbles are made of glass with high iron content. The same marble "trick" has been used for a century to great success to inhibit oxidation but this example shows just when it won't work or even be counterproductive. Lucky most B/W developers are well behaved and are quite robust to typical impurities and errors--- many, in fact, well developed to be well behaved. <a rel="nofollow" href="../photodb/user?user_id=379849">Alessandro Serrao</a> , Aug 12, 2009; 07:39 a.m. There's also the fact that finding out the purest grade becomes anti-economic or sometimes impossible. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 12, 2009; 08:56 a.m. Edward, Allesandro, good comments again and no easy answers. I say get the best you can afford and if it works, fine, but there is a photo grade. Most suppliers of photographic chemicals in any form and of any sort buy photo grade or better. This is to insure quality. Due to the limited number of companies supplying chemicals, some of our photo grade chemistry comes from the same source that Kodak uses so there will be no problem. I myself use photo grade and I know that is what I have (see photo below). BTW, Edward, I think you mean XTOL not Microdol X, but that story and the effect of Ferric ion in the water or one of the chemicals is a case in point. There was also a pacakging problem with XTOL IIRC that caused oxidation. Ron Mowrey Large photo attachment: <a rel="nofollow" href="http://static.photo.net/attachments/bboard/00U/00UC7K-164439584.jpg"> (Photo Grade Ammonium Thiosulfate -- 534 x 802 photo) </a> <a rel="nofollow" href="../photodb/user?user_id=379849">Alessandro Serrao</a> , Aug 12, 2009; 09:19 a.m. For example, just today I've bought 5kg of sodium bisulfate as a pool ph minus. It's 93,5% sodium bisulfate but for my use (as an acidifier for the bleach in the reversal process) works just fine. The permanganate comes from pharmacy (sold in 250mg tablets for personal use). <a rel="nofollow" href="../photodb/user?user_id=391082">Jordan W.</a> , Aug 13, 2009; 10:56 p.m. There have been some interesting cases in the world of organic chemistry that illustrate the pitalls of relying on purity specifications. In one widely reported case (around 2005 or so) a British research group reported that they had succeeded in carrying out a reaction called the Suzuki coupling in the absence of its usual catalyst (a palladium compound). The catalyst is normally absolutely essential for this reaction. On further examination they found that the research-grade sodium carbonate they were using for the reaction contained unreported ppb levels of Pd, which was enough to cause the reaction to "go". Another example of this is playing out in the literature right now -- a group in Germany found some interesting chemistry that appears to be catalyzed by CuI, an unusual finding in this case. However, when they used rigorously purified CuI, their yields dropped. It turns out that the original CuI sample contained small amounts of an Fe salt, and that the Fe and Cu were both required for reaction. I'm sure stuff like this happens in photographic chemistry, too -- perhaps not in B&W development, but maybe in colour, emulsion-making, or some exotic processes. Higher purity may not always better, and in some cases the chemistry just isn't well-characterised enough to draw firm conclusions. <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 14, 2009; 09:57 a.m. Jordan, what you report happens in photographic chemistry as well. I have seen chemicals pass every purity test and yet fail when put into their respective photo application. In many cases, we never found out what was wrong even after exhaustive analysis. Allesandro, you have 6.5% of unknowns in your sulfite then. Lets hope it does not affect image quality. Ron Mowrey

<h1>Myths in B&W photography #10</h1>

<a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 13, 2009; 08:55 p.m. Well, in spite of the heat, I am going on to #10. I had to search for some references before I posted this here, but this one might be of special interest. #10: All variable contrast papers give you a good range of contrasts and are equally useful. This is a myth. Some VC papers supply such poor performance in terms of curve shape (characteristic curve) that they do you a severe disservice. This is particularly true at extremes of contrast. In their article in Photo Techniques magazine (March/April 2005), Dick Dickerson and Sylvia Zawadski show the curves of several brands of VC papers. They are not identified as to brand, but are quite revealing to the discerning photographer. Some of the papers are simply not usable! VC papers are generally a blend of a green and blue sensitive emulsion, one with high contrast and one with low contrast. At extremes of Green or Blue filtration (Magenta and Yellow in the enlarger) you will get the highest and lowest component and in between you are to get a mix of the two to make a smooth intermediate curve. Many companies don't do this blending correctly and what you see is either a break in contrast in the mid tones or a fall off in the dmax or dmin area of the paper. Since their material is copyright, I cannot show their published curves here, so I suggest you test your own paper with a step scale and varying filtration or you look at the original article. Not all VC papers are created equal. Ron Mowrey

<h2>Answers</h2>

<a rel="nofollow" href="../photodb/user?user_id=2129232">Yann Roffiaen</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub4.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 14, 2009; 12:52 a.m. Well, in spite of the heat, I am going on to #10 Actually, I find your posts very interesting, if there are some debates, it's because nothing is absolute, and everyone wants to share his own experience. I'm still developping my own films and there are people like me me who are looking for some clues for better results in this forum. Thanks a lot Rowland. <a rel="nofollow" href="../photodb/user?user_id=448865">Edward Zimmermann</a> , Aug 14, 2009; 04:26 a.m. I've never heard this myth! The argument that I recall on West Coast (USA) when these papers were introduced on a larger scale--- and the argument one continued to hear in Germany as long as people bothered to talk about them (these days just accepted since there is hardly much of anything else)--- is that variocontrast papers allow one:

<ul>

<li>

to have multiple contrasts on a single page though multiple mask filtering, resp. split filtering.

</li>

<li>

reduce the numbers of papers one needs. No replacement for higher contrast papers but reasonably well for the standard hard, medium and soft.

</li>

</ul>

The debate among cognoscenti was if a given variocontrast paper is a worthy replacement for a fixed grade paper and there has never been any consensus. I, for example, has always argued: NO. The arguments were also: which variocontrast systems are any good. One should recall that although Ilford introduced the first variocontrast papers their "Multigrade system" was different from the others that followed after the war and, in particular, DuPont's Varigam (which is, more the less, the basis of today's variocontrast papers including those from Ilford).. Although vario-,poly-grade,multigrade etc. papers have been available since the 1950s they did not really, I think, take off until the 1970s together with the widespread market adoption of resin papers and the rapid consolidation of the B/W photographic paper market in response to the introduction and overwhelming success of cheaper colour films and processing. Although colour was long available it was expensive. Thoughout the 1960s TVs became more and more colour, TV and film productions went more and more over to colour and snapshots too become more and more colour and prices dropped. In the 1970s we saw the minilab arrive with a bang. By the end of the 1970s and into 1980 "1 hour photo" shops were popping up across Europe and the US. Monochrome was declared dead. It, of course, did not die but the availability of processing and their cost changed. The drugstore photo-lab did, with few exceptions, die and were replaced by service drop-offs (served by large service labs or megalabs) and mini-lab "colour only" (C41) on site machines. Demand for B/W photographic declined while at the same time the cost of silver and raw materials rose and environmental restrictions became tighter and tighter.... Variocontrast papers was the solution.. drop all the different surfaces.. focus on resin (with maybe a few Baryta papers) and one can reduce the production to a run on the coating machines every once in a while... Now only to convince the consumers that this is what they want................ <a rel="nofollow" href="../photodb/user?user_id=4260916">Jason Hall</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub2.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/1roll.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 14, 2009; 08:44 a.m. I am with Yann, I thank you for contributions! I am not printing my negatives yet, but I will be as soon as I can get it all together. Thanks Ron. Jason <a rel="nofollow" href="../photodb/user?user_id=108367">Conrad Hoffman</a> , Aug 14, 2009; 10:29 a.m. IMO, this is very important. I've tested papers at low filter numbers and found a "shelf". Different tonal values in that area don't seperate at all, and the result is visually awful. I haven't seen such problems at the high contrast end. It seems to help if the right filters (same brand and era as the paper) are used, and especially if they haven't faded. IMO again, VC papers work at their best with filtered incandescent light. FWIW it always bugs me when people talk about shortcomings in the full range of tonal values of VC papers- for me they all go from full black to full white, with every possible value in between! <a rel="nofollow" href="../photodb/user?user_id=889981">Rowland Mowrey</a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/hero.gif" border="0" alt="" hspace="1" vspace="1" width="19" align="BOTTOM" /> </a> <a rel="nofollow" href="../member-status-icons"><img src="http://static.photo.net/v3graphics/member-status-icons/sub6.gif" border="0" alt="" hspace="1" vspace="1" width="16" align="BOTTOM" /> </a> , Aug 14, 2009; 10:23 p.m. Conrad; You are right. Some tonal values do not separate with some VC papers. This is due to a lower contrast area in the characteristic curve, the "shelf". It depends on the paper. The article that I reference shows the curves. There is nothing absolute and a given manufacturer may make bad and good batches both. You should test to see if the VC paper is compatible with your needs. See myth #11 for more information. It will be coming soon. Ron Mowrey <a rel="nofollow" href="../photodb/user?user_id=1373412">Keith Tapscott</a> , Aug 15, 2009; 07:25 a.m. Ron Mowrey said: "All variable contrast papers give you a good range of contrasts and are equally useful. This is a myth. Some VC papers supply such poor performance in terms of curve shape (characteristic curve) that they do you a severe disservice. This is particularly true at extremes of contrast. In their article in Photo Techniques magazine (March/April 2005), Di

lex_jenkins · December 12, 2013

<h1 ><a href="/black-and-white-photo-film-processing-forum/00UGo4">Myths in B&W photography #13</a></h1>

<a name="00UGo4"></a><a href="/photodb/user?user_id=889981">Rowland Mowrey</a> <a href="/member-status-icons"><img title="Hero" src="/v3graphics/member-status-icons/hero.gif" alt="" /><img title="Subscriber" src="/v3graphics/member-status-icons/sub9.gif" alt="" /></a>, Aug 20, 2009; 07:49 p.m.

Well, here we go again. This is a coincidence. I was working on this myth and questions came up about it in my in-basket and in another forum at just about the same time.

#13: Developers and Fixes have limited lifetimes, usually about 4 weeks or so and should be stored in dark bottles with little air over them.

True, false, ehhh, and true in order. ~smiley~ Yes, it is a mixed answer and how do you tell when things have gone bad?

Firstoff, developers and fixes go bad. No question about it. However, the better you treat them the longer they last. I have had Dektol and D-76 last in closed clear plastic bottles filled to the top for about 6 months, but I get the same results if I have a partial bottle with a nitrogen blanket over the top of the developer.

In an open tray with a plastic top laid over it, I have had working strength Dektol last for at least 3 days if not more and give the same results.

I have tried dark and clear bottles for developer and for fix and found no significant difference as long as the solution is stored out of direct sunlight and in a cool spot such as 75 deg F or lower.

As a general rule, high contrast developers go bad more quickly than low contrast developers as they use high pH or high developer concentration and the CO2 and O2 in air does them in faster.

A quick test is to take some 35mm leader and test the time it takes to blacken the film. Every time you go to use the developer, simply repeat the test and if the developer fails to blacken the film or takes an excessive time, then it is no good.

Now, on to fixers. They go bad as a function of pH. The more acidic fixers go bad more rapidly than more alkaline fixes. The key to this is seeing either a white or yellow residue develop on the inner surface of the bottle of fixer, and/or the development of a strong odor of Hydrogen Sulfide (rotten eggs). Of course, there is a fix test that is identical to the developer test above, except the time it takes to clear is the critical feature. When the fixer fails to fix in a reasonable time, then it is no good. A fixer can be pushed a bit harder than a developer when it is starting to turn, but don't overdo it. That white residue can end up within your film trapped in the gelatin and it can ruin your negatives.

So, here is a "myth" that is very mixed in nature and has to be considered for each type of solution, but fortunately, there are handy tests for you to apply to see if you are on safe ground to trust your pictures to the solutions at hand.

Ron Mowrey

lex_jenkins · December 12, 2013

<h1 ><a href="/black-and-white-photo-film-processing-forum/00UH5w">Myths in B&W photography #14</a></h1>

<a name="00UH5w"></a><a href="/photodb/user?user_id=889981">Rowland Mowrey</a> <a href="/member-status-icons"><img title="Hero" src="/v3graphics/member-status-icons/hero.gif" alt="" /><img title="Subscriber" src="/v3graphics/member-status-icons/sub9.gif" alt="" /></a>, Aug 21, 2009; 10:16 a.m.

#14: I should use a wash aid or hypo clearing agent in my work flow to a. conserve water, b. improve image stability, c. reduce pollution etc. etc. etc.

Well, this one is true and false at the same time.

With a good wash, you need no hypo eliminater or wash aid. Washing of film with a neutral or alkaline fix is rather rapid especially with modern films and papers from first class manufacturers. Therefore, any step after the wash is not needed except for any toning you may wish to do, and of course the associated steps that go with that toning process.

With a hypo eliminator or wash aid, you may reduce the amount of wash water you use, but then you have a rather concentrated solution of another chemical that must be somehow disposed of. This does not conserve water or reduce pollution. It adds to water consumption in an indirect and hidden manner that is outside of your view.

On balance, any post wash treatment for reducing water consumption or decreasing pollution actually either balances out to be equal or increasaes pollution. Therefore, a good wash is best done alone.

A good wash will improve image stability. Any post wash wash aid will not improve it much beyond this, but good toning will generally improve stabilty. Most toners are not good for the environment either.

Ron Mowrey

lex_jenkins · December 12, 2013

<h1 ><a href="/black-and-white-photo-film-processing-forum/00UMBU">Myths in B&W photography #15</a></h1>

<a name="00UMBU"></a><a href="/photodb/user?user_id=889981">Rowland Mowrey</a> <a href="/member-status-icons"><img title="Hero" src="/v3graphics/member-status-icons/hero.gif" alt="" /><img title="Subscriber" src="/v3graphics/member-status-icons/sub9.gif" alt="" /></a>, Aug 30, 2009; 02:22 p.m.

#15: Developers do not need to evolve as emulsion technology changes.

This is false. Modern film and paper emulsions are far different than those of 50 - 100 years ago. Just consider the fact that 100 years ago we used boiled emulsions or ammonia emulsions but today we use graded iodide emulsions. This is a huge change.

About 100 years ago, we used ammonia developers, but today we use Borate and Carbonate developers instead. Who would want to go back. Even Rodinal has evolved over the last 50+ years and some Crawley developers don't seem to work the same way as they used to.

The only developer that has maintained a constant formula that I know of is D-76, used by Kodak for release testing of all B&W films. However, there are many modern developers to choose from that work best with modern films and papers.

Just a reminder that papers are not excluded either. They have evolved from Bromide / Cadmium / Mercury to Chloride / Epitaxy with Iodide in some cases. This also should include developer incorporated papers to clarify the issue.

So, the world changes and Emulsions and Developers change along with this.

Ron Mowrey

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