How to determine normal development?
I do my own B&W film at home. Can anyone give me any tips on how to tell a negative has had "normal" development? I'm trying to experiment with altering development times, but if I can't tell what is "normal", it's going to throw me off completely.
I took one class last fall, and I think I remember the teacher showing us that you can tell the negatives are properly (normally) developed if the lettering on the edges is a good solid black. Does that sound right?
I've gone back through some of my more recent negatives and noticed that the lettering is not very dark or easy to read. It's kind of greyish. Would that indicate underdevelopment? ...or overdevelopment? Or am I way off base?
Any help is appreciated.
Thanks,
Paul
Re: How to determine normal development?
I'm no expert when it comes to developing b&w film so take this with a grain of salt. :) There are so many variables (temp, agitation, strenght of chemistry) that can affect the outcome of your developed film that I think it would be hard to call anything "normal". What I would consider "normal" would be to follow the manufacturers developing directions as closely as possible and use that as your basis for experiments.
I just read an article in a photo mag that was talking about the new C-41 B&W films and how it's much easier to get consistant results with it, be cause the development is controlled by machines, and no people. They also talked about how they shot 30 rolls of B&W film back in the 80's, all of the same subjects, all exposed and bracketed the same. Then they took those rolls of film and dropped them off at dif. labs all over the city. They used mini labs, drug stores, supermarkets and custom b&w photo labs. There was no consistancy to any of the film.
Since you are the one doing the development, I think the best thing to do is to create your own, repeatable process and use that as your starting point.
Minimum black contact sheet...
First of all, the basic time/temp/dilution guidelines that come with your developer should give you a very good "normal" starting point.
Gauging over and under development by looking at negatives is pretty tough to do. If you want to fine tune the manufacturers numbers, the best way is the traditional minimum black contact proof sheet. Now, this assumes you do your own bw printing.
You create a base proof sheet exposure time by doing a test strip of fresh photo paper with NO negative. Set your enlarger lens at f/8 or f/11, and make the cone of light so it is wider than the entire contact frame. Create the test strip by giving the paper a series of timed exposures in 3 or 5 second intervals.
Process the print fully and evaluate it in room light. The exposure time you want to use for all your future proof sheets is the SHORTEST time that gives your paper a full black tone. So, it would be the first strip on the print that is completely black.
When you make a negative contact sheet using this minimum black exposure time, you get a very accurate idea of how your negatives were exposed and developed.
Combine this with what processing times you used to decide on any changes.
A properly exposed and developed negative, when proofed on a minimum black sheet, should look like a "normal" photo, with good tones and contrast.
So, if your proof looks very light (dark negatives), and you used a "normal" developing time, you are most likely over exposing your film in the camera. And so on...