I ran several contact prints of some negs I recently shot of one of my sons football games.

I exposed for 8 sec @ f5. My results on the contact sheet were very close to what I would like to see on a finished print. However my prints are more "washed out" than my contact. I have a Besslar 67 Dichro/w Nikor 50mm lens.

I am sure that I am missing a step. This is a new enlarger and lens and I am finding that it is like starting over compared to my old beginning enlarger and lens.

Any help or advice would be appreciated.

Jeff RIehl

-- Jeff Riehl (jtriehl@netzero.net), October 04, 2000

Answers

If your enlarger is the same height from the easel during the enlargement as it was during the contact printing, and the f stop is the same, then the time should be about the same. In practice, the appearance of the contact print usually doesn't relate all that well to what the enlargement will require, at least when using 35mm or medium-format negatives. If I have to use a higher contrast to get good contact prints, I know that I'll have to use higher-than-usual contrast in enlarging, but that's about as much enlarging info as the contact print yields. This is not to say that you can't work out some math to relate f stops and enlarger altitude, etc. I'd just rather spend my time printing, since I'm not that good at math.

-- Keith Nichols (knichols@iopener.net), October 04, 2000.

The lighter enlargements are due to the 'Callier effect' or more correctly the Callier co-efficient of the film.
When light passes through film it is scattered or diffused.
If you think of light radiating from the film surface in all directions after passing through it, then you can see that contact printing catches nearly all that light, and gives a certain density of print.
When you put the same film in the enlarger, then a lot of that scattered light doesn't even reach the lens, so you get a less dense print.
The amount of light loss will depend on the film and its density range, and the lighting system of your enlarger. I would expect that the exposure would need to be increased by at least 1.4 times from your contact print, though.

-- Pete Andrews (p.l.andrews@bham.ac.uk), October 05, 2000.

Jeff, when making your contact sheet, expose it so that the black in the sprocket holes just about matches the black of the unexposed film edges. That is, expose your contact sheet to the point where you can just see the holes. Stop the exposure before they merge.

When you do this, your contact sheet has received optimum exposure. Images that are too dark now represent underexposed negatives. Images that are too light indicated overexposed negatives. [Given that your development was ok].

If you use the same film all the time, you should be able to work out pretty consistent enlarging times - at least for the properly exposed negatives.

I know this does not exactly answer your question, but hope it, along with the other posts, will get you there.

Cheers - chris

-- Christian Harkness (chris.harkness@eudoramail.com), October 05, 2000.

Jeff,

The secret here is in consistency. Set your enlarger to the height you would use for an 8x10. Mark this height on the enlarger column so that you can repeat it. Focus the enlarger (use the edge of the negative carrier to ensure accuracy.) Now produce a good contact print. The aperture and exposure time you use for the contact print will be an excellent starting point for an 8x10 print from a negative that looks good on the contact. I think that your enlarger head is a diffuse source, so you should not have to adjust contrast much. The "Callier Effect" does not really apply to photographic printing at all.

This issue was popularized by Ansel Adams in his writing. Callier's work had nothing to do with what happens to light passing through film, although the subject was similar. If I remember correctly, Callier's work involved light scattered by very small oil drops, suspended in a mist. Adams (or someone) picked up on this work and used to explain the fact that diffuse source enlargements and contact prints tend to have less contrast than condensor enlargements.

-- Ed Farmer (photography2k@hotmail.com), October 05, 2000.

I'd say the most expedient way to guess from contacts is to make a test strip for the first of a set of similar shots. Educated guessing on the basis of the contacts should allow you to get pretty close to the adjustments in time and grade for the other shots.

As for the Callier effect not affecting photographic printing: Ansel Adams usually used large format. I think you won't notice much of a Callier effect there. I think almost everybody else agrees that the effect is there (as documented by the fact that you usually need contrastier negatives for diffuser enlargers as compared to condenser enlargers).

-- Thomas Wollstein (thomas_wollstein@web.de), October 09, 2000.

To quote:

"Unfortunatly, Callier was not studying the same kind of scattering phenomena which occur when we enlarge film. The kind of scattering Callier studied is related to the kind that makes the sky blue. The kind we're concerned with is related to what makes water clouds white and dust clouds gray . . . So, if you must refer to the "Callier Effect," remember it's no more than a conveinent name. Sadly, Callier has little or nothing to tell us about photographic printing."

This is from a artical by Ctein in the Jan/Feb 1999 issue of PhotoTechniques.

Yes, prints from condensor enlargers are more contrasty. No, it is de to the Callier Effect. Adams, or someone before him, latched onto Callier's work and used it to explain this. You see this effect just as much in large format work as small format work, unless you are only making contact prints. Contact prints will show the qualities of diffusion enlargement.

-- Ed Farmer (photography2k@hotmail.com), October 10, 2000.