judging the time of processing for BW

pentaxuser said:

Other safelight and other sets of eyes may be different and better but I have yet to see anyone here say they could do it OK other than the reference to michael and paula

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I have done it off and on for 15-20 years .. mostly with 4x5 and 5x7 sheet film. the article tells you what you have to look for. if you don't have a bullet safelight with the right filter and the right wattage bulb it doesn't work very well. after 5-6 minutes in pitch dark I can see fine with the green safelight I have..

Green light inspection isn’t really safe light and I don’t think it’s reliable for determining time to “snatch”. I haven’t been good at picking snatch time even by infrared though I know its light is safer.

But you could catch the “oops I grabbed the water instead of developer” kind of mistake. Or wow that really was underexposed think I will give it some more time.

You can get away with green, dim light near the end for a few seconds inspection even though the light is not truly safe. Because fog exposure won’t have much time to develop since you’re near the end.

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To the idea of lower contrast negative, which is OK: If you make lower contrast negatives the technical quality of the negative is slightly better than full (about 0.62) contrast of the ASA parameters. I think all the charts out there aim for slightly less (about 0.55)… so don’t reduce the time further from published times.

The whole discussion so far seems to assume that there is one "best" exposure and one "best" development for a given negative. I find it more helpful to think of exposure and development "ranges." There is a window of exposure from the minimum to the maximum of up to a few stops (depending on film and size) that will get you an excellent print. Similarly, with the contrast controls available in the darkroom, there is a rather large window of development times that will get you a negative that will yield an excellent print.

The object is, with testing and experience, to find an exposure and development scheme that lies in the middle of those two windows. Start with manufacturers' recommendations for both, shoot some film, and adjust as needed. If you find yourself printing everything with a #4 or #5 filter, maybe you should increase your film development times. If you don't get the shadow separation you want, adjust your working E.I.

There's really no substitute for having made a lot of exposures and learned from them.

Best,

Doremus

Proof sheets are a good tool for evaluating film development. Do a test strip on the film leader (no image), and adjust proof lighting to get about 90-95% D-max (blackness), and then expose and develop the proofs (grade 2.5 paper here, BTW). Look at them carefully (once the print is dry), and evaluate the ones that look the best, they are the ones with the better exposure (IMHO).

Danner said:

Proof sheets are a good tool for evaluating film development. Do a test strip on the film leader (no image), and adjust proof lighting to get about 90-95% D-max (blackness), and then expose and develop the proofs (grade 2.5 paper here, BTW). Look at them carefully (once the print is dry), and evaluate the ones that look the best, they are the ones with the better exposure (IMHO).

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Proof sheets are good for evaluating composition and expressions etc. But are not good for judging exposure and contrast. The optical (flare etc.) conditions are very different between contact and projection. If your goal is to make projection prints your evaluation should be done using projection prints. Otherwise you will likely be subjecting yourself to working with sub-optimum negatives and making sub-optimum prints.

Make your primary evaluation of your negatives by the appearance of the print NOT how they look on a light box.

1. Photograph "typical scene" +/- 1 stop

2. Development time +/- 15%

3. make the best straight projection print on #2 paper with recommended paper development time.

4. select best print

5. fine tune 1/3 stop and 10% development time is close enough

6. Compare the best negative to future negatives on a light box for a quick evaluation. Compare film types with caution especially between coarse grain films (Tri-X) and fine grain t-grain films (TMX) .

Once you have established a close enough method then you can make adjustments as needed. Temperature is one of the biggest challenges if you live in a hot or cold climate to maintain consistency so you learn to adjust time based on that and/or use a water bath to keep temperature as consistent as possible. Dilution is the next logical step to alter for some developers such as HC-110 or Pyrocat formulas as you can increase your work time so that pour and dump times become less important and it is easier to adjust by 5%-10% when needed. Adjusting time by -30% or -40% may become problematic when you overexpose a roll/sheet and try to offset that with underdevelopment falling below 6 minutes, thus I try to keep time consistent and alter dilution. Agitation is a matter of convenience but also can make a difference with certain developers in the edge effects or oxidation of the developer. I found it better to agitate for a long period of time at the beginning of processing then short infrequent times afterward (example 2 minutes initial, then 15seconds every 2 or 3 minutes for my total duration around 12-14minutes) . Keep in mind if you are an infrequent developer you also have the potential for stock developer failure due to age.

Sheet film shooters have the benefit of processing one sheet and make adjustments for a second sheet shot at the scene. Roll film users tend to bracket to make sure they get the best exposure and use a standard method for developing the roll. But keep in mind you will likely have a mix of high contrast, normal, and low contrast scenes on the same roll so you are usually aiming for a middle of road processing that gives good results for the normal contrast scenes. Two schools of thought - use up the roll quickly in the same conditions/lighting/subject which will result in some not so great frames, or make every shot count and only shoot what is aesthetically pleasing to you, but know there are contrast differences. Keep a logbook of your shots and notes when developing so you can study them later to get a feel of what happens when.

Some people have a preference for thinner negatives while others like it thick and contrasty. Even using variable contrast papers with graded filters , still aim for a grade 2 -3 standard print and then adjust with split grade printing as needed. Or develop for scanner range and adjust it in photoshop/lightroom.

Find a fellow hobbyist in your area that can show you examples of properly developed and improperly developed negatives (ignoring content).