Quote Originally Posted by Bill Burk View Post
CHHAHH,

Welcome to APUG,

I never know. I just make a test strip and if I don't see "too light" and "too dark" on that strip, I'll change something and try again.
That's the basic idea.

There are lots of refinements, gadgets and systems for determining print exposure, but you can, as I do, just take the low-tech and simple route. IMO it saves time and a lot of frustration.

1: stop your enlarging lens down 2-3 stops from wide open.

2: make a test strip. Start with a ten-second base exposure and then cover the strip in intervals. I like expanding intervals, so I use 2 seconds, 3 sec. 4 sec, 5 sec. etc. Your goal is to end up with a strip that has from approximately 10 to 30+ second strips on it.

3: develop your test strip fully. Evaluate it. If you don't have a strip that is too light and too dark, you need to make a new test strip. Choose a different time sequence or change your lens aperture appropriately and use the same sequence you used before.

4: repeat till you have a test strip with a too light and a too dark strip. Now, use the highlights as a guide to proper print exposure. Choose the highlight value you find correct and make a test print at that exposure.

5: evaluate the print. If the contrast is not correct, change paper grades. This will change the print exposure time, so you need to make a new test strip at the new contrast grade.

6: repeat the above till you get a print that has the approximate highlight and shadow values you want before beginning manipulations (dodging, burning etc.)

Keep notes. That and experience will tell you next time what exposures you need for a test strip from a particular paper at a particular contrast grade.

Best and good luck,

Doremus