Developing To Control Contrast With B&W Film

 

One advantage that black & white film has over color film is that you can control image contrast in B&W film by changing the developing time of the film. This is a useful technique when photographing in high contrast scenes, as the examples below will show you.

 

 

Example #1 (click images to see a larger view)

 

Black and white photograph of a white house in harsh sunlight. The film was developed normally.

Kodak Tmax 400 film, exposed at EI-320 and developed for the normal developing time of 10 minutes in D-76 1+1 at 68 degrees (20C).

 

Black and white photograph of a white house in harsh sunlight. The film was given a shorter developing time to reduce contrast.

Kodak Tmax 400 film, exposed at EI-160 and developed for 7.5 minutes in D-76 1+1 at 68 degrees (20C). This is 25% less than the normal time.

This house was photographed on a sunny spring afternoon. The sunlight is harsh, casting deep shadows; and the white house means the brightness range of the scene will be even greater. The normally developed example has too much contrast. Notice the deeply shadowed vegetation on the right side of the scene, which is too dark. In addition, there is poor tonal separation within the hedge in front of the house, and there is not enough tonal separation between the hedge and the grass.

The version that was given a shorter developing time has more open shadows, and better tonal separation in dark tones and midtones. In addition, the white aluminum siding on the house is slightly less bright. If this house had wooden siding, there would have been more texture and detail visible in the siding in the reduced-development version (aluminum siding is smooth and textureless).

 

 

Example #2 (click images to see a larger view)

 

Black and white photograph of a bungalow in harsh sunlight. The film was developed normally.

Kodak Tmax 400 film, exposed at EI-320 and developed for the normal developing time of 10 minutes in D-76 1+1 at 68 degrees (20C).

 

Black and white photograph of a bungalow in harsh sunlight. The film was given a shorter developing time to reduce contrast.

Kodak Tmax 400 film, exposed at EI-160 and developed for 7.5 minutes in D-76 1+1 at 68 degrees (20C). This is 25% less than the normal time.

Like the first example, this house was photographed on a sunny spring afternoon. The sunlight is harsh, casting deep shadows. The covered porch is a lot darker than the sunlit parts of the house. The normally developed example has too much contrast.

The version that was given a shorter developing time has more open shadows, improving the tonality of the part of the house shaded by the porch overhang. It is hard to see it in the small screen-sized images, but the sunlit areas of the white-painted wooden parts of the house show more texture and detail in the reduced-development version.

 

 

How It's Done

The amount of reduction in developing time varies depending on the film and developer you are using, and can be anywhere from 20% to 30%. If you look at my Tested Developing Times, many of them show a Normal time and a time labeled "N-1." This is the time you would use for that film and developer combination to reduce contrast. If you do not see an N-1 time listed for the film and developer combo that you are using, try a 25% reduction as a starting point.

 

Film Speed

You will notice that in my examples above, I shot the normally developed photographs at EI-320 (my normal exposure for Tmax 400 developed in D-76 1+1), but the reduced developing time versions were shot at EI-160. This gave the reduced development films one stop more exposure than the normally developed film.

This is because reducing the developing time also causes a drop in the film's effective speed. With most films and developers, the speed loss is about one stop; so the normal procedure is to simply set your meter to a one stop lower film speed. Because of the speed loss, you must plan to use development to control contrast when you actually shoot the photographs. If you expose at the normal film speed, then decide to reduce developing time afterward, your images will be underexposed.

If you are shooting on 35mm or 120 roll film, you must shoot the whole roll in the same lighting conditions using the same reduced exposure index. Make sure you mark the rolls after you shoot them so that you will know what developing treatment each requires when you get back home!

 

Can You Adjust Contrast Without Changing Film Developing?

Yes, it is possible to do so. If you scan your film, you can manipulate the exposure using curves in Photoshop to open up dark shadows and bring down overly-bright light tones. If you print in the darkroom on traditional photo paper, you can use a lower-contrast paper (or alower-grade contrast filter with variable-contrast paper). In both Photoshop and the darkroom, further adjustment can be done through dodging and burning (selectively darkening or lightening parts of the image without affecting other areas).

Although you can use a normally-developed negative and adjust the contrast in the darkroom or in Photoshop, it is much easier to work with a negative whose developing has been tailored to the scene contrast. It is always better to start with the best negative possible because it is a lot more work to get a good image from a film that has too much contrast, and the image quality will ultimately be better from the properly-developed film.

 

Can You INCREASE Contrast?

Yes, you can increase contrast by using a developing time that is longer than normal. In the real world, this is probably something you will never want to do if you are aiming for a realistic rendering of the subject. It is far more common to encounter lighting conditions that work with normal developing or that require reduced developing. In the 30 years I have been shooting black and white film and developing it, I have never once needed to increase developing time to increase contrast.

Some photographers like very high contrast renderings, which is a valid artistic decision. If you want more contrast, I recommend increasing developing time by 25% (multiply normal developing time by 1.25) for Kodak Tmax 100 and Tmax 400, and Ilford Delta 100 and Delta 400 films. For other films, increase developing time by 50% (multiply normal developing time by 1.5). Tmax and Delta films build contrast faster than other B&W films.

Increasing developing times will not have as much impact on the film's effective speed as reduced developing times do. With most films, you'll see no more than a 13 stop increase in the film's effective speed. I recommend either shooting at the normal speed that you would use for that film and developer combination or increasing the exposure index by 13 stop. So, for example, a film you normally shoot at EI-320 would be shot at EI-400 and a film normally shot at EI-100 would be shot at EI-125 when using a longer developing time.

 

 

 

 

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