dhananjay_n

It's a great rig. It will handle all of those focal lengths without any problem. Cheers, DJ

Brush agitation probably provides the most even development. Development requires by-products to be removed fromthe emulsion and replaced with fresh developer. Unfortunately, you have a laminar layer atthe emulsion surface - a thin layer of the solution is literally stuck to the surface of the emulsion. Most agitation schemes rely upon diffusion at the laminar surface to excahnge developer and by-products of development. Brush agitation is obviously much more efficient since the bristles literally break up the laminar layer.

 

Brush development was/is used by the astronomy crowd. The downside is that you have to do one sheet at a time and you need good technique. There is also some risk of scratching the emulsion if you use poor quality brushes or poor technique. I think you might find some discussion on the technique at either lfphoto.info or apug.org - some of the folks there do use brush agitation. I think a hake brush is recommended (the Japanese type without metal ferrules). Ideally (and this is possible with smaller negs like 4x5), use a brush wide enough to cover at least the width, so one stroke covers the entire film surface. If not, you will need to work on technique to ensure even brushing. As with all developing techniques, agitation and a steady, consistent action are the goal.

 

Cheers, DJ

The stain in a properly processed negative should actually be somewhat difficult to see (unless you had a neg developed in a non-staining developer on hand for comparison). Staining developers provide two kinds of stain - image specific (good) and general (bad) stain. The tanning and staining itself is the result of the byproduct of pyro oxidation. Pyro oxidized by reducing silver results in staining and tanning closely allied to the reduced silver (image specific stain). Pyro oxidized by aeriel oxidation etc results in an overall, general stain that acts as fog. General stain is easy to see because the whole negative has this overall stain. Image specific stain is more difficult to see - it is visible primarily in the highlights where there is more black silver density interfering. Obviously, if you have a comparison neg made in a normal developer, the comparison makes it easier to see. The easiest way to figure out the spectral charateristics of the stain on your negatives is with the help of a color densitometer.

 

The exact color of the stain is dependent on a number of factors. The process is basically one of tanning and is heavily dependent on the gelatin and on a number of other factors.

 

Cheers, DJ

The following may be a possible solution. Most enlarging lenses have a standard Leica thread (I don't know if this is true for the larger focal lengths, but it seems true for most enlarging lenses). I remember that Rodenstock used to make a Leica to Copal 1 adapter (I believe this is also available through Calumet). Any enlarger lens with a standard Leica thread can be screwed into the adapter and the adapter is screwed into the Copal shutter - so you basically end up with a front mounted enlarging lens. Use the aperture on the lens and the shutter for timing exposure. The advantage of this setup is that you can use multiple enlarging lenses on the same shutter. Cheers, DJ

Depends primarily on the paper you are using. Enlarging papers are very fast and a low wattage bulb will work fine, around 25W should be plenty. If you use a contact paper (Azo is the last of these, but the results are quite superb), you will need a brighter bulb (300W R40 bulbs are used by many folks who use Azo, although at least some people have reported good results with dimmer bulbs that have more UV output). If you print negatives larger than 8x10, you may want to invest in a vacuum frame because traditional contact frames are said to do a poor job of ensuring firm and even contact with large areas. Get a large sheet of black board/card and a metronome.

 

To work, place neg and paper in frame. Cover with card. Switch on metronome and light. Uncover the frame by removing the card and count off beats on the metronome. To end exposure, cover paper with card and switch off light.

 

Cheers, DJ

I doubt your Speed Graphic has enough bellows to handle a 19" lens. As you mention, the Artars are not telephoto lenses and so you would need about 19" of bellows to focus at infinty and more to focus on anything closer. 19" is about 480 mm, not 210mm. The Artars are superb lenses but you may want to look at something like the 8.25" or 10.75" focal length. You should be fine with coverage on 4x5 - even with movements. The Artars have about a 45 degree coverage angle. The 19" lens actually will cover 8x20. Since the Speed Graphic has a focal plane shutter, a barrel lens would be an economy.

 

I would keep my eyes open for a red dot Artar. These are coated and some have the formula tweaked a bit to make them perform better at infinity distances (the Artars were originally designed for close work on repro stuff but the design holds its correction remarkably well at infinity distances also). The coating is more important - with four air-glass surfaces, flare can be an issue.

 

Cheers, DJ

There will be differences in the way tones are reproduced depending on the relative sizes of the areas in which the tones occur. There are unlikely to be differences between the formats in tonalities of large areas, since the characteristic curve is the same. Said differently, if the white dress lands on zone VII and the black tux on zone III, those tonalities will look the same on a print regardless of format. The differences start showing up when you start looking at smaller areas. This is obviously related to the differences in the sizes of the formats - the larger format records small areas with more film area, compared to smaller formats.

 

An analogy might help. Imagine you are a painter and you are dealing with a region of grey with small differences in tone. If you were painting the whole this on a small canvas, you would probably use one shade of gray to represent this small region of grey. If you were painting this on a larger canvas, you would probably use a few different shades of grey to capture the subtle differences within this area. In image reproduction terms, it really doesn't matter whether the limitation is the fineness of a brush or the limits of grains of silver. In other words, there is always a limit at which the medium throws away information or is insensitive to information.

 

There is always some amount of irradiation within the film emulsion - that is light from bright areas bleeds into the the edge of an area that should be recorded with light from a dark area. This reduces resolution as well as local contrast. In larger formats, this affects much smaller regions compared to smaller formats. That is, in a smaller format, the loss of local contrast happens to larger objects in the scene as compared to larger formats. Imagine a small rock with actual differences in tonality. In a small format, irradiation will reduce the local contrast between regions of differences in tonality i.e., the rock will look grey (with some variation but much smaller variation - just a sort of grey rock). With a larger format, irraidation affects the information about the rock to a much lesser extent. The local contrast in the rock will be preserved to a much higher degree. There will be more contrast within the rock in a print and it will appear livelier and more contrasty. This does not mean irradiation is not happening in the larger format - it just affects smaller things, for e.g., a rock loses local contrast and looks grey in a print from 35mm, a pebble would look grey from 4x5 and a small rock chip would look grey from 8x10.

 

There are lots of other differences, for e.g., what Patrick pointed out about adjacency effects not translating equally across formats. This makes it difficult to draw more than broad generalizations about this. The light and the subject and the medium interact to either enhance or diminish these differences. But the general principle is that larger formats will preserve local contrast out to smaller objects. In MTF terms, the larger format will have higher contrast on smaller frequencies.

 

So, to answer your question. No, it is not that any tones are missing but the fidelity of distribution of tones relative to subject is different across the formats.

 

Hope this helps. Cheers, DJ

I have not actually made the tests you suggest. However, I have tried both approaches (TF3 and regular rapid fixers) empirically and have some thoughts on the issue. In my opinion, many post development processes that are used to accentuate stain (e.g., the post fixing bath in alkaline solution or used developer) only serve to increase general stain rather than image stain. In using ABC pyro, I have found scant difference between using an alkaline fix and a regular acid fix. I know that acid environments inhibit stain formation but the crucial question is how long does the stain take to form and stabilize - the recommendation for an alkaline post-fix soak only serves to increase general stain, in my opinion, and based on recent recommendations of others like Gordon Hutchings. So, the image stain has clearly stabilized prior to that. My sense is that most of the image stain forms during development in situ around the developed silver grain. Any stain after that seems basically general stain, the stain equivalent of fog. Unfortunately, image stain is very difficult to see since it is so localised to the silver. The general stain is a lot easier to see - the whole negative will have a greenish (or other, depending on the developer) color. I think it is a need to see the stain that has prompted so many people to accept high levels of general stain.

 

So, to answer your question, I would hypothesize that having a low sulfite content is crucial at the development stage during which most of the image stain forms, but not later.

 

Caveat: These are observations made after developing lots of film using alkaline and regular rapid fixers. It probably is well worth running some more controlled tests of these different factors.

 

Cheers, DJ

If you are having trouble seeing the areas you have to dodge and burn (because there is no projected image), place a work print next to the contact printing frame to assist you in finding the required places. Also, you probably are using a dim light if you are using enlarging paper. Switch to a slow contact printing paper (Azo), and use a bright light - it makes it easier to see where things are on the neg. It really is very easy to do. If the dodge/burn patterns are very complicated, place a tracing paper over the negative and smudge some pencil over the dodging areas - you will end up pwith a dodging mask. Cheers, DJ

Comparing Dagors and Ektars can be hard - they are quite different designs. The commercial Ektars tend to be Tessar derivatives (except some of them, notably the 203mm f/7.7 which is a dialyte). Dagors are among the first anastigmatics and consist of two symmetrical cells arranged around a stop, each consisting of three cemented elements.

 

Both of them are very good lenses, and whether you would see any difference would depend on the application you are putting them to. The Dagors have more coverage, especially as you stop - coverage reaches about 87 degrees at f/45. Commercial Ektars have less coverage (while wide field Ektars based on a double gauss design offer more coverage, the wide angle Dagors offer more also). Dagors tend to be uncoated but the ebenfits of coating to a design like this is minimal, with the low number of air-glass surfaces. Kodak Ektars would generally be coated, but again the design really does need the coating. Dagors are supposedly notorious for the uncorrected zonal spherical aberration that is responsible for focus shift, but I think this refers to the use when you remove one of the element and use only one element to get a focal length approximately 1.8 times the regular focal length i.e., if you try using it as a convertible, a task some say it was not really designed to do (the individual cells are not corrected for coma, unlike the Protars). When you use the full lens, it is a very sharp and flexible lens. Like I said, they are both excellent lenses and I would use other considerations (e.g., condition of the lens, price etc.) to aid i nthe decision.

 

Cheers, DJ

Carl Meyer is not to be confused with Hugo Meyer. Hugo Meyer were a reputed German firm (Paul Rudolph designed the plasmat when he was working for them). Carl Meyer was the name under which Burke and James marketed lenses assembled from surplus stuff. The name was probably coined as a combination of the prestigious names Carl Zeiss and Hugo Meyer. The general opinion is that these are poor lenses.

 

Kodak lenses are of pretty uniformly high quality. Their quality control was considered excellent. The designs are fairly staid but tried and tested ones. You can tell the age of the lenses using the serial number which will have two letters - the year of manufacture is obtained using the keyword CAMEROSITY (C=0, A=1, M=2 etc). An L inside a circle denotes that it was lumenized, the Kodak term for coated.

 

Cheers, DJ

The Sinarons were made for Sinar. So, I guess they have the Sinar seal of approval, maybe they went through two quality checks. The lenses are highly likely to perform identically. Cheers, DJ

I'm presuming this is B&W. For long exposures that get long enough to require reciprocity correction, you actually need to do N- processing. The reason for this is that the correction is to ensure adequate exposure in the shadows. But the highlights are getting more light and will not be suffering from reciprocity failure to the same extent as the shadows, so the correction pushes them higher up the scale. The actual amount depends upon the amount of reciprocity failure. As a starting point, look at N-1/2 for exposures over 1 second, N-1 for exposures over 10 seconds and N-2 for exposures over 100 seconds. Cheers, DJ

The position of the stop is important in correcting certain abberations. Also, the barrel distortion from the stop in front was considered preferable to the pincushion distortion from the stop behind. Having said that, there are a couple of other issues worth keeping in mind. When you use a single element behind the stop, the nodal point is actually behind the glass, so the bellows draw is generally longer than the marked focal length. Similarly, when it is placed in front of the stop, the nodal point lies in front of the lens, which does takes on a somewhat tele construction. So, if your camera does not have sufficient bellows, the single element can be placed in front of the stop. The performance will probably be lower, but given that the stop position is probably not optimum anyway, it may not matter. I am not familiar with the Mamiya lenses that were mounted with all elements in front of the stop. Is it possible that this was a leaf shutter and the entire barrel of the lens was front mounted on to the shutter with a separate iris at the correct position? If that was the case, the iris (which would be the stop) would be in the correct position and the leaf shutter is only a way to control the exposure. Cheers, DJ

Convertibles were compromises to keep weight and price down in an era when most stuff was contact printed. Especially when using only one of the elements, performance is noticeably down from using the full lens. That said, some of the designs are quite remarkable. The Protar, for instance, is a surprisingly good lens, even when using only one of the cells. The Turner Reich is based on the Protar design - one of the four elements of the Protar is split and you end up with 5 elements. Centering four elements accurately is pretty hard to begin with and the job gets really difficult with five. So, the quality of a TR can vary depending on how well the centering was done. I notice the lens was made in Fairport, which pegs it as a somewhat late lens - Guundlach moved from Rochester to Fairport sometime in the 30s, so this must be after that.

 

It is hard to answer your question without trying out the lens. It also dpeends on your intended use and how much you are planning on enlarging etc. But in general, expect the full lens to perform well at the kinds of stops used in LF photography. The individual cells will probably be worse than that, which might be what you want in a portrait lens. Although really pleasing portrait lenses get their effect from uncorrected spherical aberration.

 

Hope this helps. Cheers, DJ

It's a Turner Reich in a Rapax shutter. The TR is triple convertible, probably designed by Gundlach, and essentially like A a Protar VII. It consists of two cells around a stop. Each cell consists of five cemented elements (the Protar has four, odds are the extra element in the TR was to get around patent issues). When both cells are used together, you get the 7.5" focal length. You can also use each individual cell on its own by placing it behind the shutter to get the 11" and 14" focal lengths. When using both cells, you can expect good anastigmat performance i.e., something like a Dagor. When using individual cells, some of the corrections are lost and performance drops - there are ways to mitigate that loss. General rules for using triple convertibles. When using both cells, longer focal length element goes in front. When using each cell separately, the cell goes behind the stop. When using single cells, it is a good idea to use a sharp cutting monochromatic filter to restrict the spectrum (to reduce chromatic abberation) and stop down (to reduce other abberations). Coverage when using both cells is probably around 75 degrees, single cells will have much less, around 45 degrees. So your lens will be quite at home on a 5x7 or 4x5. Cheers, DJ

There was an article by Gordon Hutchings or Bob Herbst in View Camera a few months ago regarding using a UV densitometer which might be well worth a read. If your argument is that you can still calibrate your process to a particular paper without reading the stain density, I would agree with you. But then, you don't need a densitometer to calibrate your process to a particular paper either. I'm merely pointing out that the stain in a pyro negative is an inherent part of the density and contrast in that negative. To that extent, measuring the silver density alone is, at least technically, going to yield a wrong number. That is what I meant by having to reach for softer papers. That is, if you believe your paper requires a negative with a density range of 1.2 and you make measurements of only the silver density, you might adjust yor process to get a silver density range of 1.2, but the stain can add as much as 0.3 more density, which means you end up with a negative range of 1.5, which will require a softer paper. Now, it is only a number and the proper interpretation, as you have explicated, will obviously still allow you calibrate your process accordingly. I was only pointing out that the blue channel readings on a densitometer will yield different readings from the normal mode. That is because the stain blocks blue light much more effectively than white light. Hope this clarifies things. Cheers, DJ

The stain will affect densitometer readings. The stain is very effective at blocking light, especially UV light. A normal reading through a densitometer will only measure the silver density and ignore the stain density and you will find that your negatives are printing more contrasty than you would think - you will always reach for the soffter grades of paper. You could take a reading through the blue channel for a somewhat better idea and there are some densitometers that will give you a reading based on UV light. What you use depends on what the fianl use is. If it is for alt processes that are mainly exposed by UV light, you may prefer the latter. If silver gelatin, which is typically exposed with blue light, you may prefer the former.

 

It should be noted that for your speed point, which is the exposure that just produces density in the shadows, the stain should technically be irrelevant, since there is supposed to be no stain in the shadows but often there is some amount of base stain. And you will definitely find a fairly pronounced stain component in the highlight densities, so the stain defintiely matters for your N/N+/N- testing. Having said all this, it is worth adding that you can get much the same information from exposing film to step wedges, developing them to different contrasts and printing them on the paper of your choice.

 

Cheers, DJ

D76 is the classic solvent developer. Solvent developers utilize a high amount of sulfite. Sulfite serves as both a preservative (protects the developing agent against oxidation) and as a solvent. Sulfite is used in most developers as a preservative, but when used in high concentrations (as it is in D76), its solvent action becomes an important part of the developer characteristic. The sulfite actually dissolves part of the silver, and some of this silver is replated back on emerging grains. The solvent action has a number of results on the structure of the image. It tends to increase speed because the solvent action uncovers latent image sites. It also tends to reduce graininess because the grain has been nibbled away at. It, however, reduces acutance or the perception of sharpness. This is because the replating action results in a somewhat poorly specified grain. Under a microscope, you will see a good amount of density at the centre of the grain and this becomes somewhat diffuse as you move to the edge of the grain due to the solvent action.

 

When you dilute D76 1:1, the sulfite concentration is effectively reduced in the working solution. It still has its preservtaive properties but the solvent properties are considerably reduced. Hence, slightly larger grain and somewhat better sharpness. As mentioned earlier, diluting the developer could also change the characteristic curve. Basically, as you dilute the developer, there is enough developing oomph to develop the minimally exposed shadow areas but there might not be enough in the heavily exposed highlight areas. So, the highlights often are held back, relative to the shadows, especially if you use intermittent agitation. You can experiment with many of these issues - for example, many people will develop to the same contrast (that is, they will extend development time so that they get the same density range), but because the highlights have been held back relative to the shadows, you will get better separation in the shadows as compared to the highlights (when compared to the developer used straight at full strength).

 

The 1:1 is used one shot for a couple of reasons. One, because the sulfite content is now low enough that protection against oxidation in storage is reduced. Second, the developing agent is also more diluted - you need a certain amount of developing agent to develop X square inches of film. The capacity of a diluted developer is going to be lower and there is often nothing to be gained by reusing it, especially given the risks of oxidation in storage. Maybe there are also issues of consistency involved - maybe it is more difficult to get repeatable results with the diluted developer.

 

Hope this helps. DJ

A sextet at this point. The Ries - time tested and abso-bloody-lutely solid and a pleasure to use. Cheers, DJ

Richard Henry in his book "Controls in B&W Photography" had some data that bears on this issue - if I'm remembering this correctly, I think he concluded that the silver content was not related to the Dmax that could be obtained (but I could be wrong on this). However, there is enough anecdotal evidence that there was something to some of the 'old' emulsions that has been lost. What I have heard very often is that modern films simply do not push well enough i.e., the gamma infinity seems lower. Older films, especially stuff like Super-XX was supposed to be very versatile on this count in terms of being able to get a huge range of gammas by varying development. I must agree with this take myself. It may not be an issue for folks who enlarge because they typically develop to much lower contrast indices. But if you are contact printing on Azo or any of the alt processes, you really do need a negative developed to a much higher contrast. I can eke an N+1 for these kinds of processes out of most films, but little beyond. I don't know if this is related to silver content or some other aspect of emulsion making, but I think it is related to something else. The Dmax has actually increased in modern emulsions, so I doubt that is the stumbling block. It is the maximum obtainable slope of the characteristic curve. Cheers, DJ

Actually, I don't think it is too far off the mark to say the only silver halide in a contact printing paper would be chloride. The silver halides have different sensitivities with chloride being the slowest and iodide being the fastest. They also differ in color and spectral sensitivity. Contact papers (or gaslight papers) typically used only silver chloride. The downside to silver chloride is that it is slow, but that was not a problem in its intended application in contact printing boxes that used huge amount of light. Enlarging papers are more likely to use bromide or a mix of bromide and chloride (sometimes iodide) because enlarging papers need to be faster and the increased sensitivity of bromide is necessary for this use - the use of these papers in a contact printing box would have necessitated extremely short exposures. Am I confusing cause and effect - is it just an accident of history that contact papers used only silver chloride or does silver chloride make for a contact paper? My own speculation is that in contact printing applications, the use of a silver chloride only approach does seem to provide something. Note that most of the alt processes based on silver (e.g., salt printing, POP) tend to be chloride based (note also that most of these processes tend to have the same long scale characteristics claimed for Azo). My guess is that silver bromide came into vogue in printing papers around the same time that enlarging became more popular and demand increased for faster printing papers. What I can attest to is the fact that when you try to contact print on an enlarging paper (that contains bromide), the results are quite different from a print made on a chloride paper. Can a paper with the same characteristics as the contact papers be made with silver bromide instead of silver chloride? Maybe, but I'm yet to see one. Cheers, DJ

There are two phenomena that are sometimes confused with each other. True solarization is due to gross overexposure. Normally , increasing exposure will increase density. However, you reach a point when extra exposure actually decreases density - this phenomenon is called solarization. Take a look at Ansel Adams "The Black Sun" fro an example (I think it is printed in "The Negative"). I think the effect you are referring to (although it is hard to say from the description) is the Sbattier effect, which is sometimes incorrectly called solarization. The Sabattier effect is typically achieved in the following manner. Expose a print and start developing it. Halfway through development, turn on the light i.e., expose the print again. You will get tone reversals and often a line across the zone of tone reversal. Ed Buffa;oe has a page on the Sabbattier effect and controlling it at www.unblinkingeye.com which might be worth a look. Cheers, DJ

To each their own and I'm admittedly biased since I use DBI, so take this with the appropriate amount of salt. But with regards to some of the comments made so far.

 

1) Fogging: When done correctly, there is no fogging from the dark green safelight. I have tested this with a step wedge and a densitometer - admittedly, I was using a pyro developer that further desensitizes the film and hardens the emulsion but there was no increase in base fog till about 3 mins of continuous exposure to the green safelight - typical inspection times are much shorter than that. If you are truly uncomfortable with this, use a desensitizer or infrared inspection. Note: The dark green safelight was turned on after three-quarters of the developing time was over.

 

2) The eye is a lousy densitometer: Perhaps true, but it is not as bad as folks make it out to be. Actually, the problem with the human eye is that it is extremely context dependent and is hugely influenced by sorrounding values. If you use two black cutout cards with holes in them and use them to estimate densities by comparison with a calibrated step wedge, you would be genuinely surprised at how well it does.

 

Also keep in mind that folks like Michael and Paula (and a whole legion of others) print on Azo - two grades available (2 and 3) and apparently the negatives print OK - they got to be doing alright. DBI may not be for everyone and I'm not for one minute suggesting the eye is as accurate as a densitometer, but I think there are lots of judgment calls - aesthetic and technical - in the system leading upto a print. For example, deciding what should be a zone III etc really is a judgment call. Given all these judgments calls, that last bit of feedback can be quite useful to have.

 

The trouble is that most folks see this as a DBI vs time/temperature thing. The best way is to use them in tandem with one another. You should have a pretty decent idea about the time. The inspection allows you a check and feedback before the point of no return (i.e., fixer). A little practise gives you a good idea about what a properly developed negative should look like. As others have suggested, use time and temperature the first few times and take a look at the neg before dropping it into the fixer. Over time, you will develop the facility to recognize a propserly deevloped negative.

 

Having said all this, I think there is something else worth pointing out. Most folks who DBI seem to be large format photographers who contact print their negatives, typically on Azo or utilizing alternative processes. I believe the longer density range and higher CI required by these processes makes it easier to judhe compared to the thinner negatives required by enlargement processes.

 

Cheers, DJ

The f-stop is f=F/n where F is the focal length and n is the diameter of the entrance pupil. In the Stolze system, the stop is f^2/10. The system is similar to the old US stop system except that the US stop sytem uses f^2/16. These systems are proportional to exposure time. There probably were a bunch of other systems but the only system that has survived is the f-stop system.

 

I don't think the stops will conform to any of these systems. I think it is a millimeter scale and the lens just opens up way beyond f/18 for brighter focussing.

 

Cheers, DJ