I love the picture above. It’s not so much the subject ( a throwaway portrait), it’s the aesthetic of the photo, and particularly, the grain. It has a beautiful traditional black and white 35mm look, a function of the classic optical rendering (a 50’s era Nikkor H 50 f/1.4 Leica Thread Mount), the tonality of a classic emulsion (Tri-X), and the overlay of grain inherent in the film process. Grain is the random optical texture of processed film caused by small metallic silver particles developed from silver halide. Unlike pixelation, film grain is an optical effect, the amount of which depends on both the film stock and observational distances. For me, its the grain that sets traditional black and white film photography apart from digital black and white and why many of us prefer the labor intensive film process to digital black and white.
Which is ironic, because as a general rule, back in the film era, grain used to be a thing we tried to avoid. We chased newer emulsions that gave use a cleaner, less grainy look. C-41 films like Ilford XP2 and Kodak CN400 gave an almost grainless rendering and were popular for that reason; or we handicapped ourselves by shooting slow speed films like Kodak Panatomic-X (iso 32) or Ilford Pan-F (iso 50) as much for their lack of grain as their enhanced tonality. If we needed decent speed but unobtrusive grain for 11 by 14 prints, we shot Plus-X (iso 125). Or we avoided grain altogether by shooting medium format. When we needed low light capabilities, the quick easy shot, we opted for 35mm Tri-X or HP5, maybe even pushing it a stop to 800 iso, developing in a speed-enhancing developer like Microphen and crossing our fingers.
But a curious thing happened with the advent of digital photography: we realized the power grain had as an aesthetic characteristic in itself. When seen in contrast to the sterility of digital capture grain revealed its inherent importance to the look of film photography. After we lost the rearguard battles of resolution, dynamic range and tonality to digital capture, we were left with the grain, and we finally recognized the particularity of film, its “look,” was the result of the organic quality of the grain and how the medium itself, with its random imperfections, was a necessary part of the image itself. And now we shoot film for the grain.
So, many of us who cut our teeth on film photography have now discovered the role grain plays in what we perceive to be a proper aesthetic of a photograph. We’ve found ways of changing film grain characteristcs in the darkroom by using certain chemicals, and we often choose film with specific grain for different occasions. In many ways, what sort of grain we want for a given look – coarse, subdued, plentiful – is as important as our choice of lens.
If film grain has aesthetic value, high ISO digital noise does not. Not all sensors produce ugly noise at higher sensitivities – some produce noise almost “filmlike” (The Ricoh GXR M Mount comes to mind), but it’s usually only a matter of degree, not quality. In digital capture, the equivalent of film grains are the individual elements of the image sensor, the pixels; just as small-grain film has better resolution than large-grain film, so too an image sensor with more numerous pixels will usually result in an image with better resolution. However, unlike pixels, film grain is not the limit of a given film stock’s resolution. While film grain is randomly distributed and varies in size, image sensor cells are the same size and are arranged in a geometric grid. In general, as the pixels from a digital image sensor are set in straight lines, they are less pleasing visually – thin, as it were – then randomly arranged film grains. Viewers will reject an enlargement that shows pixels, when a film enlargement with ample grain and lower resolution will look normal, and ‘sharper’ at a normal viewing distance.
Various software exist to mimic the generic “look” of scanned film by converting to grayscale and adding random noise to emulate film grain. However, the results are often not convincing, because:
real film grain is not random noise
real film grain looks dramatically different across different film stocks
real film grain expresses itself differently based on exposure
A discerning eye can tell it’s not film, because real film grain, and the real film look, is a function of innumerable variables that go into the choice, exposure and development of a roll of film. To add grain to a digital image so that it would completely mimic film grain you would have to match the measured dynamic range and spectral response of a specific film stock and then correctly incorporate that film’s actual film grain into the image, duplicating how that grain expresses itself relative to exposure, stock, and development process.
For me, film images look like images should look. Digital capture has a transparency to it that’s off-putting, even when you run them through an emulation like Silver Efex (see above). There’s a certain thinness to digital capture, because it lacks the organic texture intrinsic to the film image. The organic nature of film grain adds a layer of separation from reality, and this separation, far from adulterating the image, helps feed the viewer’s imagination. It’s this separation from strict reality that gives grain it’s power and character. Real film grain gives us something more than an indexical transposition of the “real”; it feeds the imagination. That’s why, in an age of crystal clean 3200 iso digital capture, I prefer to shoot HP5. And I always push it a stop to 800 iso, just for the enhanced grain, because its a look I simply can’t duplicate even with a dedicated black and white tool like the Monochrom and Silver Efex.