What happens when lengthening the dvelopment of the negatives?

Question

Will it build up or decrease the density of the negative? also, will it help to increase or decrease the contrast of the image?
Thanks!

Answer 1

When you increase the development of negatives, it increases their overall density (shadows included, contrary to the previous answer), increases their graininess, and their contrast is increased. You can use this technique for artistic reasons, such as to achieve a high-contrast look, or to try to save a poorly exposed roll of film.

Answer 2

This applies to Black & White film only.

If the film is properly exposed and over-developed your highlights will darken more as development lengthens.

Increasing development is usually used when the film has been underexposed, either intentionally (known as "pushing" the film, i.e., exposing at ISO 800 instead of the rated 400) or accidentally.

The best negatives and prints will result form correct exposure and processing.

If you need additional information, get a copy of the Kodak Darkroom Data Guide. The book "Object & Image: An Introduction To Photography, Third Edition" by George M. Craven would also be a good addition to your personal library.

EDIT. Well, Robert M., I'll stand by what the Kodak Darkroom Data Guide and the section in "Object& Image" on processing B&W says on the subject. I taight B&W darkroom classes years ago.