Sunday, January 21, 2018

Film Grain and Image Aesthetics


Grain is present in all film, but as grain size relates directly to film speed, the rule is: when going for the finest grain choose the slowest film speed possible and, conversely, when looking to enhance grain choose a high-speed film. The "possible" in the low grain rule takes lighting conditions and whether or not you're working with a tripod into consideration.

This grainy rendition was created by exposing Tri-X 400 at ISO1600 and "push-processing" (extending development time) the film using D-76 at full strength (no dilution). This resulted in a dense negative that was then printed using a #3 grade paper. The background was extensively "burned in" during printing. Torrey Pines Beach, 1988, Tri-X 400 exposed and push processed to ISO1600.
        
Today there are both “normal” (random grain placement) and T (for tabular) grain films. Tabular means the grains are “cloned” to be consistent throughout the emulsion. While this may seem academic, T grain films have a “smoother” look overall when printed, while “normal” grain films have a more “photographic” look associated with them. For example, you can get Tri-X 400 or T-Max 400, the latter having grain structure that is somewhat smaller and more light efficient than the grains found in the older emulsion formulations. While these T-grain films do offer finer grain in equivalent speeds when compared to the older formulations, the faster T-grain films are still grainier than slower T-grain films.

Some photographers do everything possible to reduce grain in their images--they shoot with the slowest speed films; they keep developing times to a minimum; they enlarge on low-contrast papers; and use so-called "fine-grain" developers. (Use of these developers usually means the loss of a portion of the speed at which you rate the film.)

Other photographers go the opposite route, and do whatever possible to enhance grain for graphic effects. You can boost grain by shooting with the fastest film available; by overdeveloping film (within reason); and by printing on high-contrast papers (or multi-contrast papers that allow you to change the grade by filtering the enlarger light: for example, a magenta filter for higher contrast.). Another way to enhance or smooth grain is to choose between a condenser or "diffusion" enlarger, the latter yielding a smoother grain look. As the visual effect of grain is linked to the degree of enlargement (magnification), some photographers either enlarge their prints to huge sizes, or take small portions of the frame and enlarge that section (cropping) to increase the image magnification even further.

Smooth grain images result from using a moderate speed film or inherently fine-grain film like T-Max, developing for lessened time, being careful not to overexpose, and printing on a #2 or lower grain using a diffusion head enlarger. This scene was photographed in 1989 on T-Max 400 with exposure biased towards the highlights. The film was developed in T-Max developer at 30 seconds less than the recommended developing time with 1-minute agitation intervals.

Most photographers do not get obsessed with grain, as long as it doesn't get in the way of visual communication. There is a school, however, that expresses the opinion that grain is an inherent characteristic of the "photographic" image, and that emphasizing grain, or not being too concerned when grain becomes evident, stamps an image as eminently "photographic." Grain is also used by photographers to add a nostalgic, mysterious or even ominous note to an image.

The best way to discover ways to enhance or diminish grain is to test various film/exposure/development combinations. For example, shoot a few rolls of Tri-X and do a “ringaround” of exposure, changing ISO and even exposure compensation as you shoot. (In other words, make images in low and moderate contrast light, both of the same scene, and bracket both ISO and settings, say by one to two stops of exposure and setting ISO at 200, 400 and 800 ISO.) Do this with a few rolls and develop one in a fine grain developer (which, as mentioned will have you rating Tri-X 400 at maybe 200 or 320) and one in a more active developer such as D-76, diluting 1:1 and 1:2 with water.

After development make contact sheets and then pick a few images that are over, under and well exposed. Enlarge a few frames to a minimum of 8x10", and use a loupe to help “predict” the resultant look of the grain on future frames shot at the same settings.

Once you have done this, make notes for your future field work. These notes will become your “grain” diary and will help you make choices for various subjects, scenes, and settings, and create just the right degree of expressive grain for your work. That way you will “stamp” or embed each roll of film, making the frame an “original” that truly records your mood and aesthetics of the moment you snapped the shutter.

Note: Pushing (through development) and rating ISO 400 film at ISO 1000 and above will certainly yield more grain. You can also punch up grain by developing any film in a highly-active developer, such as a paper print developer, for about 1.5 minutes. This will yield a very dense, but printable, negative that has "popping" grain.