Some Developer Theory needed here

Discussion in 'Black and White' started by julien_boudreau, Dec 22, 2010.

  1. Greetings,
    I've been exploring B&W film for about 6 months now, and can say that this is the direction I wish to pursue (I sold my D90 to afford a lens and two film bodies, along with some chemicals, film and processing equipment). I also took at B&W photography class at the University Fine Arts department, where I developed film and printed in the darkroom. I was extremely pleased with the results, and ultimately, the experience. This being said, I always felt I needed a bit of "theory" to be clarified;
    1. If you pull a film, say shooting TriX @ 200, do you develop this said roll at the 400 times or 200 times? My assumption is that you want to pull film to OVERexpose the negative by 2/3 to 1 stop, pulling more shadow detail. Wouldn't developing for 200 times just counter this over exposure?
    2. Other than the film's intrinsic properties, what determines contrast? What are the effects of developer dilution, time, and film rating. I know that pushing film will boost contrast. Does pulling reduce contrast?
    3. Grain. I love it (when it's well defined, and crisp). Does pushing or pulling increase or decrease grain?
    4. I'm going to shoot some Delta 3200 over the holidays. I've been advised to rate it at 1600, as this is really a 1000-1600 film. Do I develop at the 3200 times or the 1600 times? Is the point of rating at 1600 to overexpose a bit to prevent a thin negative?
    I've had a lot of success with Rodinal 1+50 and TriX. I love that look. The tonality is stunning. I'll be experimenting with stand development and different dilutions soon. I also have DDX on hand for the newer grain films, such as Delta 3200.
    Thanks,
    J
     
  2. Pulling a film means to shoot it at a reduced box speed then reduce development. It gets confused with shooting a film at a reduced E.I Exposure Index. So if you Pull a film you shoot it at a speed lesser than the rated speed and develop it at the lower speed. Now if you want to overexpose a film to get more shadow detail you use the lower E.I. and develop it at the normal time.
    I know that was as clear as mud. Now if you Push a film you underexpose the film say it is an ISO 400 film and you shoot it at 1600 you under exposed it by 2 stops so you develop it longer. With most developers it adds contrast and density with a loss of shadow details and increased grain. Here is where it gets tricky. Some developers tend to give a speed boost of 1 or more stops without the increase of grain and with little or any loss of shadow detail. Examples of these are Diafine Acufine and XTOL. Xtol mostly 1/2 a stop gain. More tricky is that not all films react with these developers in the same way.
    I hope you have a great Festivus and others can confuse you more than I did.
    Larry
     
  3. Larry,
    Thanks. That was very clear. I think I want to overexpose to gain some shadow detail. I'll most likely be printing them in a darkroom within the next year (taking the class again, building darkroom with friends). With TriX I was getting good results by over exposing slightly. It was easier to print, and Rodinal gave it some good punch. I started using Xtol, as this was the school's developer. I never liked it much - found it a bit flat. Everything "came to life" with Rodinal.
    So this being said, with 3200 film, if I want to really pull out some shadow details, I could rate this at 1600 and develop for the 3200 times? I'll be using DDX, which I believe has s slight speed push?
    Festivus for the rest of us (Restivus?)
    J
     
  4. Another Conundrum 1600 and 3200 speed films are really 1000 and 1200 speed films designed for push processing. They are flat contrast films designed with the knowledge that you will push them so this adds contrast. They being 1000-1200 speed allow more shadow to be captured but are mostly shot in high contrast and low shadow areas.
    I tend to find that I can get better grain with some ISO 400 films shot at 1600 and then pushed than using a 1600-3200 film and pulling it or developing it normally. Now back to the last post Neopan 400 in acufine at 1250-1600 7 minutes 20c to me is sharper and has less grain than any of the 1600-3200 films on the market and with shadow detail.
    Example.. Warning this is real ugly.
    http://www.flickr.com/photos/jokerphotography/5257325882/sizes/l/in/set-72157625462845683/
     
  5. Julien, if your Xtol developments came out 'boring' then you should have developed for longer, which inevitably gives you 'snappier' negatives.
    Second if: you spend so much money on film as in 'shoot Delta 3200' then you better shoot it at 3200, and develop it with a DD-X time between 3200 and 6400. That will rock (bigish grain), believe me. Why not Delta at 1600? Xtol-pushed TMY-2 or Neopan400 just look sweeter* at 1600 than Delta3200 at 1600.
    * yes, I admit it officially: this is rather subjective!
    Remember that redish light tricks your meter towards underexposure by 0.5 to 1 steps/apertures (i.e. it is too 'optimistic' with the exposure time)
    Have fun, Pete
     
  6. 2. Other than the film's intrinsic properties, what determines contrast?​
    For the chemistry, the composition of the solution can determine or influence contrast. Keep in mind that exposure to liquid energy is similar to exposure to light energy. The composition of the developer, in terms of bulk of each ingredient and in terms of proportions of ingredients to one another, can be used to regulate contrast.
    There are similar properties of intensity, duration, sensitivity in the wet side of development; it's the wet and dark version of the same sensitivity and reaction problems you're probably used to solving with light and aperture and shutter with the camera. In the wet, they're frequently solved with duration, dilution and design of the solution. Agitation is just a variation of dilution by using mechanical action; no matter; look for duration, dilution and design. By design I mean, what's in that developer recipe?
    One famous example is in Ansel Adams' use of Beer's Two-Part Developer. The recipe is in "The Print." Beer's Two is used with two bottles of developers whose solutions are combined in water in varying proportions for the purpose of changing the contrast of the print. [It's meant to be a print developer, but it the same general principles apply.] Pretty much what you'll see there is that one part is hydroquinone-heavy. The other is Metol-heavy. Hydroq will have a fast-acting, but harsh, developer. It brings in great cold blacks. The metol is much softer, but is "slower" and softer. Metol is so slow and soft you just about have to send it an engraved invitation to get it to burn in some blacks. The two kinds work together well as part of mixing their characteristics; and, together, become super-additive developer solution which is much more powerful in its intensity then either component alone. Together, a super-additive developer of hydroquinone and metol will have about five times the power of each by itself. So, if you get to reading recipes, you might notice that hydroquinone only or metol only developers seem to need about five times as much of developer in the recipe. In a superadditive developer recipe, quantities of near or below 5g of each would be common. To see what I mean, look up recipes like D-23 and compare them with the recipe for D-72 or D-76.
    Next, those other ingredients in the recipe. What are they for? I have felt that those other ingredients, excluding water (which is more media and temperature influence), settle in to two kinds of functions: setting environment and/or contributing a characteristic.
    By setting environment I mean, some developer recipes will have plain hypo in them, I think, just for lowering the pH. [pH can be used as an intensity gauge for developers; film developers will be near pH 9 (some at 8); paper film developers will be near pH 10.] The hypo is handy in the lab, and won't really contribute much fixing characteristic; so, if you need to drop the pH, add a pinch of hypo. It'll carry a pH in water near pH 4. So, by adding a little 4 you could bring down a borderline 10 to a high pH 9.
    By contributing a characteristic I mean, provide some quality to the solution the developers can't provide. Like, take buffers for example. Borax (Go, Mule Team!) buffers slow down the reactivity of some of the compounds. This has a couple of effects. Time does count in developing, so sometimes a physically slower reaction is helpful for bringing out a characteristic; the reactions aren't just start and stop, but start-progress-at-maybe-an-inconsistent-rate to a point then change-rates-of-progress then-stop. Well, the buffer can smooth some of this out. Also, since the solution can be reacting the entire time, not just when it's providing us the desired reaction in the presence of film, a buffer can have some "preservative" type qualities. As a rough rule, I've found that salty items and sulfurs are usually there as characteristic contributors. Borax is a salt; it's a common buffer. Sodium sulfite has some buffer qualities; it seems to slow down the reaction enough so that the other components don't consume themselves immediately.
    Part of feeling these recipes out has to do with recognizing that this stuff will be reacting as long as it is in the presence of itself (like, when wet) and also in the presence of film. When it has film emulsion to chew on, the rate of reaction will step up quickly; but, it'll still need about ten seconds to overcome inefficiency by soaking in and getting started.
    I'm not a chemical engineer, but by reading some published recipes it's not rocket science to start extrapolating your own ideas about some of these components. Every component contributes to the solution; it may make multiple contributions or do very little; the commercial solutions were put together by people who knew what they were doing. Some of these solutions seem to rely on some complex, custom-made components; many seem to have been built hard to understand on purpose, for commercial reasons beyond just the effectiveness of developing. Was the designing of metol, for instance, a quest for a softer developer, or one that just someone owned outright for decades? Depends. I have no idea, and don't pretend to know; but, if you read a bunch of recipes and have some lab sense, you can start to feel some of this out as a general idea.
    A free copy of one of my homemade recipes is on the web page below. Try "guest" and "agxphoto" if you hit a password challenge. I had to lock it up just because.
    https://guest:agphoto@www.agxphoto.info/cover/mirrors/ch3/chapter3.html
    The Plain Jane Beta Chi will come out similar to Dektol, but it's rougher.
     
  7. I realized that in the post above I failed to state outright that the developer solution itself will have components that fill various roles. The developer solution will probably hold: developer (active component), buffer, environment setters, other contributors, and plain media (like water; could be a colloid, depends; really, it's most often water). So, I guess to follow what I was saying above you'd have to realize that the whole solution would be named "developer" and an individual component inside that solution which does the developing: I also call it, "developer."
    Here's a good listing of some proven recipes printed from Unblinking Eye:
    http://unblinkingeye.com/Articles/Developers/Formulas/formulas.html
    It's a good page.
     
  8. A good mental exercise is to look over some recipes, like those at the Unblinking Eye page listed above, and start to parse the roles of the components. Notice also their quantities, as a proportion to other components and the solution as a whole. Quantity tells us about the minimum amount need to get going; and, proportion gives us a clue to intensity.
    So, with a big sheet of recipes like that, after a while, you should be able to read the recipes and note and understand ideas like: Okay, this says, developer, buffer, a pinch of environment setter for pH adjustment, another component to add a characteristic, maybe yet another component to keep one of these other parts in line and limit it, maybe another component to fuel the REDOX and get things going on that line of the recipe. Also, note the order in which items are added. It's part of mixing the developer, but it also tells us what would or should react with what and give us a clue about what's intended and what's to be avoided.
    So, a D-23 recipe should easily read:
    • Distilled water (temperature control and media)[Note temperature is a mechanical form of duration control, but has minimum and maximum limits.]
    • Metol (developer)
    • Sodium Sulfite (minor buffer and environment setter, promoting the work of the developer)
    • Cold water (dilution control and media)[Diluting the solution to use plain media as an intensity control, while not exceeding a maximum temperature; really, though, often at the end of a recipe like this just to stabilize the volumes involved without mucking up a hard to measure amount taken up by the particles of what's added before; some might be liquid or powder, etc.]
    So, the recipes you see would be not only lists of items, but lists of functions performed by developer components.
    Contrast ends up being a function of intensity. What'll happen is that some of this is not a steady-rate build up, but a pass or fail yes or no test that's brought to a maximum quickly in the event of a positive result; with the fuel consumed quickly and to its maximum, or not at all and to its minimum, the paper will be at its maximum black or white. It's that slow, steady, middle-grade development which is more likely to bring a variety of grays.
    Part of the point to feel out is that the development is not just a hypothetical pass or fail, steady progress; but, instead, is a real, tangible, physical item; this will place limits and generous inefficiencies on the process.
    The process is so inefficient that it could be reasonably said that no one had a good chance of understanding it until about WWII. We were simply too short on the laws of thermodynamics it takes to feel out some of the inefficient flows of energy through a media. When Matthew Brady made that photo of President Abraham Lincoln, there was a lot of chance involved in being successful. At the time photography was invented, we were way too short on the laws of thermodynamics.
    Well, so, I will stop now; but, one of the parts of the process which affects contrast is the cumulative characteristics of components within the developer solution. Hypothetically, it is entirely possible to manipulate contrast almost solely by adjusting the developer's contents. Developer composition and design is so influential, that I find it helps to make some suppositions about what developer I will use later when composing a photo in camera.
    Developer composition directly works on both the negative development and print development. Reversal processes or instant films are very tight, smoothly functioning subsets of real good developer choices.
    So, developer components count toward contrast.
     
  9. ...another contrast principle that is important to understand has to do with both exposure and development. That phrase, "expose for the shadows, then develop for the highlights," has meaning...which is that most shadow detail typically develops to its full extent within a relatively short development timeframe, while highlight values continue to develop for a much longer time. This allows the photographer to place the important shadow values high enough on the exposure scale to ensure that they don't get lost later in processing, and then to cut the processing time back, as necessary (depending on highlight values) to help ensure that highlights are held back enough to print with a bit of detail. Not all film/developer combos respond equally to these exposure/development variations, so you will need to do a bit of experimenting to get on the right track. For further reading, I highly recommend both the classic Ansel Adams book: "The Negative," and Henry Horenstein's "Beyond Basic Photography." Good luck!
     
  10. There is a general rule, expose for the shadows and develope for the highlights. What I have found is that most B&W films should be rated 1 stop lower than their nominated rated value, ie ISO 3200, rate it at 1600, this will give you good shadow details (I trust you are exposing manualy and setting your exposere based on mid Grey) If you develope the film normaly ie ISO 3200, then you should get a good negative, i have used this technique a lot with Delta ISO 3200. If shoooting on a high contrast subject, slightly reduce your developement time, if shooting on a flat dull day, increase the developement time to get more punch out of the negative, you will know when you have it right.
    The issue with 35mm film is that you are developing potentially for a range of contracts settings, so unless the whole roll of film has been exposed at a similar contracts range, it can be dificult to get a consistanly good negative.
    Good Luck and good to see some B&W traditional technique being used. Regards RE
     
  11. I don't believe any films have true ISO. Tri-X is supposedly around 320, and Delta 3200 is around 1000... nothing to worry about, just develop it at the 3200 time. Think about it - why else would one 400 film have a different development time to another 400 film, with the same developer?
    Since pushing film increases contrast, then pulling it will decrease contrast. I've never tried pulling, I think of it as a waste of speed. It does have benefits though; reduced grain and less base fog.
    An old film will have lots of base fog. Example (from experience) I used a Kodachrome 50 (or 64?) and used/developed it as 200 or 400 speed film. The film is basically too dense to be scanned. That's because the development time was long enough to bring out the fog; if I had used it at 50/64 it would be much better. Pulling it would give the film more light from a scene, which would need less development time to bring it out. Less development time will mean less fog is brought out.
    I follow the 1.5 rule, and so should you. Use 200 as 400? Multiply the stated development time by 1.5. In general, multiply or divide by 1.5 to the power of stops increase/decrease. E.g. 100 as 3200: say the 100 time is 6min. 6*1.5^5 = 45min. Long time! (100>200>400>800>1600>3200 is five stops) So I would increase the developer temperature to decrease the time, which will have effects too, I hear. For non-BW films just use the Tri-X time as a guide. Works well for me.
    Consider a see-saw. Development time (D) is one end, exposure (E) is on the other. With the exposure being brief (pushing) the E end hits the ground and the D end points up - with little light received, you'll need to develop it longer to bring out sufficient silver (i.e. enough density). With a long exposure time (pulling), E points up and D hits the ground; there's so much light hitting the film that it won't take long to bring out the silver.
    Lately I'm into BW reversal. What you do is, expose the film, develop it as you would, then bleach it - the developed silver is removed but the unexposed silver is left. After fogging, the film is developed again. All of the remaining silver can now be brought out. So, for example, if someone's jacket was light in real life, then a lot of silver on the film would be formed showing the jacket - that's dark on the film. After bleaching, there's a little bit of silver left for the jacket. It's then fogged and developed, so now the jacket is represented by clearness, not blackness. Try it!
     
  12. there are developers with different characteristics. This will definitely be of use http://shop.silverprint.co.uk/Black-And-White-Film-Developer/catalogue/462/
     
  13. iso200 or 400 colour film developed as 3200
    00djlS-560702184.jpg
     
  14. development increase grain (remember, more speed means more grain). Films like Delta 3200 are actually high speed emulsions, so they will have less grain at 3200 than, say, a 400 speed film pushed to 3200.
    00djlV-560702284.jpg
     
  15. woops, I just realised that this was from 2010. I made the mistake of assuming it was recent. *X&$#**X&$#**X&$#**X&$#*!
     
  16. Delta 3200 is a little unusual. If you look at it's characteristic curve, you find that there is no linear region. The ISO formula takes two points on the curve and assigns an ISO speed value.
    The speed rating is based mostly on the foot of the curve, the part that is important for shadows. In most cases, black and white films can be exposed at a stop or two more, which will help the shadows and still not overexpose the highlights. The exception is very high contrast scenes, such as with parts in the sun and parts in the shade. Consider two people, one in a shadow, maybe from a tree, the other in direct sun. Film can almost do this, and if you pull (to decrease contrast) you have a little better chance. The is well described with the zone system, and Adams "The Negative" the usual reference.
    It is basic to the chemistry that longer development gives darker negatives. But highlights (more exposed region) develop faster, and so pushing does bring up the shadow just a bit, but does even more on the highlights.
    Compensating developers like Diafine, or stand development, are two ways to give enough development for the shadows, usually with increased EI, while not overdeveloping the highlights.
    An important way that film works is that it contains large and small grains. The range of grains is what gives the lower contrast. The larger grains have a better chance to be hit by a photon, and so are more sensitive. (It usually takes more than one, but still.) With pushing, and with high speed films in general, the image is made more from larger grains, visible at higher magnification.
     

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