Darkroom newbie

Photo Chemist · Mar 13, 2020

I finally had a chance to really get into darkroom printing the last couple of weeks. I have started with printing contact sheets. My question is about exposure time and development time.
1.) I usually have to stop down to f22 to get about 20-30 sec. exposure time, depending on the negatives. Somewhere I read that ideal times are 10-30. Why is that? Or does it not really matter? If f22 works for me, should I change it? (because from what I read, f8/f11 is ideal for 10-30 sec).

2.) Development: I use dektol. Suggested development time is 45 sec. - 1min. If I remove it before then (for example 30 sec), does that mean the chemical reaction wasn't complete on the paper? Can I control the appearance of the print that way? Or is it wiser to play around with exposure time and leave the paper in the developer for 1 min?

You guys have always been so helpful - I appreciate any insight.
Thanks!

pentaxuser · Mar 13, 2020

There might just( but not necessarily) be what I understand to be a diffraction problem with very small apertures such as f22 which is why f8/11 is recommended. Unless you need 20-30 secs for dodging and burning then I'd use f8/f11.

Developing is meant to be taken to completion so stick to the developer maker's time's and yes use exposure time, dodging and burning, if required and contrast control to alter the appearance of the print

Printing is a great adventure so enjoy the experience

pentaxuser

Fraunhofer · Mar 13, 2020

1) Nothing wrong with that, depending on print size and light source this can happen. When using very high magnification a high f-stop will result in diffraction effects, but I never encountered these in practice.
2) Paper is usually developed to completion, i.e. go with the time recommended by the manufacturer: if you pull early your blacks become greys. Developing longer is less of a problem but in extreme cases can lead to unpleasant shifts in tone. So use exposure to control your print and not development. There are exceptions, but these are for more advanced users.

Hope that helps.

Mr Bill · Mar 13, 2020

Photo Chemist said:
1.) I usually have to stop down to f22 to get about 20-30 sec. exposure time, depending on the negatives. Somewhere I read that ideal times are 10-30. Why is that? Or does it not really matter? If f22 works for me, should I change it? (because from what I read, f8/f11 is ideal for 10-30 sec).

Well, if you want to dodge or burn, which is manipulating the exposure on different parts of the image, you need enough time to handle the tools. As long as you have enough working time you're ok. If your exposures get really short then it's possible that you won't get consistent changes in exposure adjustment, so you want to be aware of that.

I wouldn't personally work at f/22; I think you may be visibly losing fine detail by then due to diffraction. Best way to judge this is to do a comparison test at a wider aperture. Opening up about 2 stops, to about f/11 ought to be enough. So if you make a critically focused print at f/11 and another at f/22, then inspect the fine detail in each, this should let you make a decision. I'm guessing that you'll find a slight degradation at f/22.

Photo Chemist said:
Suggested development time is 45 sec. - 1min. If I remove it before then (for example 30 sec), does that mean the chemical reaction wasn't complete on the paper?

I concur with giving a full development. Something I would do with a new paper/developer combination is to test the "sensitivity" of the developing time. I would expose two test strips and put into developer at the same time. At the minimum development time (45 sec) in this case, pull one strip out. Let the other go beyond the max time. (I'd probably go up to about a minute and a half in this case.) If I found that the extended time development gave a darker black then I would judge that the minimum time was not long enough. A second thing that I like to know is whether extended development can help to bail out a slightly underexposed print; an additional test can show this effect.

I think it's worth doing the tests yourself, even if only once. Then you have a real sense of how significant the effects are.

Photo Chemist · Mar 13, 2020

Mr Bill said:
Well, if you want to dodge or burn, which is manipulating the exposure on different parts of the image, you need enough time to handle the tools. As long as you have enough working time you're ok. If your exposures get really short then it's possible that you won't get consistent changes in exposure adjustment, so you want to be aware of that.

I wouldn't personally work at f/22; I think you may be visibly losing fine detail by then due to diffraction. Best way to judge this is to do a comparison test at a wider aperture. Opening up about 2 stops, to about f/11 ought to be enough. So if you make a critically focused print at f/11 and another at f/22, then inspect the fine detail in each, this should let you make a decision. I'm guessing that you'll find a slight degradation at f/22.

I concur with giving a full development. Something I would do with a new paper/developer combination is to test the "sensitivity" of the developing time. I would expose two test strips and put into developer at the same time. At the minimum development time (45 sec) in this case, pull one strip out. Let the other go beyond the max time. (I'd probably go up to about a minute and a half in this case.) If I found that the extended time development gave a darker black then I would judge that the minimum time was not long enough. A second thing that I like to know is whether extended development can help to bail out a slightly underexposed print; an additional test can show this effect.

I think it's worth doing the tests yourself, even if only once. Then you have a real sense of how significant the effects are.

Ok. that makes perfect sense. I will definitely do a development test to see the difference.

Fraunhofer said:
1) Nothing wrong with that, depending on print size and light source this can happen. When using very high magnification a high f-stop will result in diffraction effects, but I never encountered these in practice.
2) Paper is usually developed to completion, i.e. go with the time recommended by the manufacturer: if you pull early your blacks become greys. Developing longer is less of a problem but in extreme cases can lead to unpleasant shifts in tone. So use exposure to control your print and not development. There are exceptions, but these are for more advanced users.

Hope that helps.

Sounds good. Thank you for your help!

pentaxuser said:
There might just( but not necessarily) be what I understand to be a diffraction problem with very small apertures such as f22 which is why f8/11 is recommended. Unless you need 20-30 secs for dodging and burning then I'd use f8/f11.

Developing is meant to be taken to completion so stick to the developer maker's time's and yes use exposure time, dodging and burning, if required and contrast control to alter the appearance of the print

Printing is a great adventure so enjoy the experience

pentaxuser

I will open it up then. Thank you! And, yes, it's been an amazing adventure ... this far.

Luckless · Mar 13, 2020

My understanding is that the overall duration isn't overly critical to the exposure itself as compared to overall energy of the light involved, unless you're pushing it to either extreme... Brighter light over five seconds results in the same chemical reactions as a suitably dimmer light over 30 to 60 seconds. But you'll possibly run into issues trying to use really really bright and short fractional second duration [like high end lab grade electric flash kind of lighting], or if you're stretching too little light over too long of a time.

So if you're not doing 'anything fancy' with the exposure, such as dodging/burning operations, then it may be worth choosing the shorter duration exposure option. [Which is why some printers like to use mask layers on their negatives over manual dodging/burning. Consistent print-to-print reproduction on the operation, and you can get set up and do a long run of the same print with only a few seconds exposure time before swapping for the next sheet.]

All that said, which enlarger are you using? Being able to stretch out and pick a comfortable working time for your exposures is a handy thing, and the option to use a neutral density filter, or increased/reduced brightness options on the head may be something worth looking into.

Control and options are good things.

Andrew O'Neill · Mar 13, 2020

If f/22 (are you negatives quite thin?) is working, then Bob's your uncle. I always develop to completion.

Photo Chemist · Mar 13, 2020

Andrew O'Neill said:
If f/22 (are you negatives quite thin?) is working, then Bob's your uncle. I always develop to completion.

No, not all of them. Some are thin (I haven't made friends with Delta 3200 yet...those seem to always be thin for me; and the thin ones seem to be harder to print) but not all of them. I honestly wasn't sure what the issue was or "the right way" was. I'd rather learn it right from the beginning because it will be harder to unlearn it, and then relearn it the right way.

Luis-F-S · Mar 13, 2020

Read Fred Picker's Zone VI workshop. Available used for around $5 at auction. He'll explain how to determine if your negatives are "good" or if you can improve on them. L

jimjm · Mar 13, 2020

In the darkroom, there's not always a "right" way to do things, but there are recommended practices to optimize your results and get the final look you want. Usually, the manufacturer's recommendations for processing film/paper/chemicals is the best place to start, as these have been extensively tested in various situations.
Most (not all) camera and enlarger lenses are designed to perform optimally when closed down a few stops. Quality enlarger lenses may not show much difference at various apertures unless you make big enlargements, but there are very few "bad" enlarger lenses out there.
If you're making smaller prints like 5x7", it's common to get short printing times, especially with thinner negatives. Unless you need time to dodge/burn, and you're getting consistent results from print to print, there's nothing wrong with this. You can also use ND filters to lengthen the times, or multicontrast filters will also add time. If you're not using any filters now, a grade #2 filter will give approximately the same contrast level, but will require a longer exposure.
It is generally recommended to develop the print for the full recommended time, rather than pulling it early. Shadows and highlights in your image develop at different rates, so this is not the step where you want to compensate for improper print exposure or contrast setting. Plus it make it harder to replicate your results with any certainty.

voceumana · Mar 13, 2020

For contact printing, it doesn't matter what the f/stop is--it just controls the amount of light. When using the lens to enlarge a negative, most lenses perform best one or two stops closed from wide open. Diffraction reduces sharpness at very small apertures.

Time your exposure so your prints are fully developed in about 2 minutes with Dektol diluted 1:2 (the standard dilution). Your gradation will look better with a fully developed print.

kevs · Mar 14, 2020

Photo Chemist said:
I finally had a chance to really get into darkroom printing the last couple of weeks. I have started with printing contact sheets. My question is about exposure time and development time.
1.) I usually have to stop down to f22 to get about 20-30 sec. exposure time, depending on the negatives. Somewhere I read that ideal times are 10-30. Why is that?

Misinformation. Don't believe everything you read!

Photo Chemist said:
Or does it not really matter? If f22 works for me, should I change it? (because from what I read, f8/f11 is ideal for 10-30 sec).

All things being equal, it doesn't matter whether you expose for five seconds or five minutes. I recently made a few prints on a slow paper that needed six minutes' exposure at f11; mind you the neg is rather dense.

Photo Chemist said:
2.) Development: I use dektol. Suggested development time is 45 sec. - 1min. If I remove it before then (for example 30 sec), does that mean the chemical reaction wasn't complete on the paper? Can I control the appearance of the print that way? Or is it wiser to play around with exposure time and leave the paper in the developer for 1 min?

As others have said, unlike film, paper is developed to completion so leaving it in the dev longer is rarely a problem. If you remove prints from the dev too soon, you'll get weaker blacks, and mid-tones and highlights will be lighter or absent. It also depends on the temperature of your dev; cold developer won't develop prints as quickly as warm developer will but again this is rarely a problem.

Good luck and have fun in the darkroom.

M Carter · Mar 14, 2020

To control short exposure times (I print very large, but I start at 5x7 to get to know the neg, then up to 8x10 or 11x14 and eventually the big paper -so I'm familiar with trying to dodge a 4 second exposure...)

You can buy a sheet of ND lighting gel from any online camera store; they come in strengths like 1/2 stop, 1 stop, 2 stops. I'd grab a sheet of 2-stop. You can cut a piece out of it to fit your filter drawer, and you'll have plenty left. You can even stack it. It's about six to eight bucks a sheet and the sheets are something like 18x24" or so.

If you don't have a filter slot, you can use a standard camera ND filter and rest it in the under-lens carrier or the red-filter holder - get creative. Even a small one, 46mm or whatever will work. You can even get one to match your enlarger lens threads.

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