Originally posted by vonBaloney Yeah, my film days are solidly behind me anyway, but if I wasn't doing the printing then I just wouldn't be interested. To me, that's most of the game. Of course, if it is cheap enough and they wanna send me some small prints then I can use those instead of a contact sheet as a starting point. I was reading about caffenol in another thread, which I had never heard of (which was strange because in school there were all kinds of "alternative processes" explored -- Liquid Light, etc). Turns out it was invented after the last time I did any darkroom work. It was been a while, but if I wanted to shoot some b&w film these days, I'm sure that's what I'd do -- all developing and printing at home but with less nasty chemicals.
The problem with caffenol developer is the coffee. There is no way of determining if the Nescafe you used last time is the same as the Maxwell House you are using this time. Does the composition of instant coffee change over time enough that keeping the same jar of it specifically for mixing developer will give consistent results? The nice thing about it is that there should be no toxicity.
OTOH, the amount of Metol in D76 is very low, Hydroquinone is used in skin creams, Sodium Sulfite is pretty benign unless one abuses it, and really, the quantities involved in a home based darkroom are going to be so small that there will be no environmental issue anyway.
As with anything, a little common sense goes a long way.
---------- Post added Jan 7th, 2022 at 12:53 PM ----------
As promised, how to determine film speed. This is enlarger based, not scanning based, but one should be able to modify the methodology to scanning film.
Note that once this is dialed in we are no longer metering the shadows but rather we are metering the highlights. The nice thing about this is that light meters are generally more accurate at higher light levels anyway.
I think a lot of people inadvertently get it
backwards, and try to match paper to negatives.
I think it best to match negatives to paper.
Film is much more responsive to control than
paper.
Figuring out how to expose a film starts in the
darkroom.
Take an unexposed piece of the film you want to
use. Process it as per the manufacturers
instructions.
Set your enlarger head to a height that will
give a nice magnification for the print size you
want to make, most of the time.
Default to 8x10 if you can't decide.
Focus the lens and set stop it down 3 stops or so to its best aperture if you know it.
Do not change these settings for the duration of
the procedure
Put the processed film into the neg carrier and
make a series of exposures to find the time it
takes to make D-max.
You now have your stock exposure time for that paper, aperture and print size.
Now it's time to figure out your ISO.
You can set up a test target. or just go out and make pictures. What you are doing is finding out how your film speed/ developer combination handles bright areas. I like sunlit clouds for this, as it's about as bright a white you will get in nature.
Shoot a negative or series of negative and process the film however is normal for you, and expose it to your chosen paper using the settings you calculated for the D-Max paper test.
If your clouds are blown out, you need to shorten your development time, and may also need to lower your ISO. After a couple of exposure tests, you will probably know where you have to go, and how far until you get a suitable ISO/developer time to retain detail in the highlights. If you find your shadows are getting murky, you might find you need to lower your ISO, and/ or adjust your base exposure to the paper if you have had to shorten your film development time a lot. You might have dropped the base density + fog.
This technique is far better with sheet film, but will help quite a bit with roll film as well.
Now when you go shooting, you are metering the highlights rather than the shadows, as St. Ansel recommended.