Film

Scanning, recognition, and choosing

Whether scanning or using, keep in mind that there are real differences in film. However, sometimes the points made remind me of the days before audio CD's. There were endless discussions about which cartridge, arm, stylus, turntable, and so on worked better on records. To a few with the time (and money) to pursue that sort of thing, there were said to be better results. It is the belief of the POASSB crew that, while you can save a lot of money by talking endlessly about photography rather than practicing it, such behavior defeats the purpose of owning a camera.

We should first say something about black-and-white film. "B&W" was the original photographic medium. It still exists, and even in the digital age remains a popular medium, something that I have explored in another column. Most of the points noted here about color print film apply to B&W.

B&W has generally been available as print film, producing a negative, however, there are black-and-white slide films. It was a difficult process, and never very popular.

Traditional B&W film is very stable when processed. There is also a chromogenic B&W film. It is processed in the C-41 process commonly used to develop color negatives. This arose because the C-41 process was available just about everywhere, while the traditional process was essentially done by hand. Chromogenic thus became the popular form for producing prints that could be copied in office copiers. Along the way, photographers discovered that chromogenic films have wide latitude — they're great for night shots because they don't wash out the lights.

I haven't noticed much difference in scanning chromogenic films, although some scanners may try to give them a color cast. A little software manipulation will usually relieve that. But chromogenic films should be stored like color films: cool, dark, and all that.

There are two very different kinds of color film: prints and slides. When print film is processed, it is developed into a negative. If you look at a negative (top image), the colors are strange, because they are the reverse of what you saw, and an orange tint or mask is also added. The negative is then printed onto paper (a print, which looks like what you saw, center), and both the negative and print are returned to you. When slide film is processed, it is developed and put into a cardboard or plastic mount (typically), and returned to you. If you look at the slide, it is basically a small representation of the scene you photographed (bottom).

The chemicals and procedures used for negatives are different from those for slides. If you look on your print film cartridge, you'll probably find "Process C-41" somewhere; on slide fillm you'll find "Process E-6", or, if you have Kodachrome, "Process K-14." Kodachrome is very stable, especially if stored properly. You can scan old Kodachromes without too much concern. Some scanners have a separate channel for them, because their color range is wider than other films.

Ektachrome and similar processes are not as stable in the long-term as Kodachrome. If you are scanning these, older slides may be faded. Again, some scanners have a separate channel for faded slides, and it can make a big difference. You may run across some other oddities. Ektachrome was available in an infrared-sensitive form. The colors on this are all over the map, depending on filtration. And sometimes people will deliberately use the wrong process, creating odd-looking slides on negative film, or odd-looking negatives on slide film. careful.

A slide looks best when projected, and that means setting up a projector, screen, finding a good room, and so on. However, the projector lamp can be very damaging. If the slide falls out of the gate in the projector, it can melt. The light itself can change the dyes, so slides should not be projected for long periods of time. I expect this to become more of a problem as projectors become obsolete, as people will substitute lamps that fit rather than use the correct ones. Slides can also be viewed against a light source with a magnifier.

Traditionally, slide film produced "sharper" results than print film. However, beginning in the late 1980s, print films improved rapidly, closing the gap. The first generation of high-speed (ISO 400 +) of both slide and negative films were also very grainy.

One area that should draw more concern than it does is exposure. Slide films are persnickety about exposure, and many in-camera meters cannot handle them properly. If you are going to use slide film, you need to develop a good sense of exposure; if you are scanning a slide, expect trouble if it's not right on — which is usually the case. The overwhelming majority of film used is print film, so naturally, that's what cameras are going to be adjusted for. Print film that is mis-exposed also won't scan well, but it may have more details that can be brought out than slides.

All film suffers greatly when underexposed (not enough light). Unfortunately, it is very easy to underexpose! With slide film, if you overexpose, you wash out the brighter, lighter colors, and they are lost. However, print film can stand several stops of overexposure. Some people routinely did that, because it produces better colors.

Just as digital sensors vary, so does film, and they will all scan differently. The big names in film are Kodak and Fuji. You'll also hear from Agfa, Konica, and private labels. Most scanners have a Kodak channel and a Fuji channel. Some will have channels for Agfa. The private labels are often from Ferrania, an Italian company, and resemble Agfa more than anything. As I scan more of this stuff, I'll report further.

revised 29 March 2010; original 14 July 2003