Microfilm is not designed for pictorial photography. It is made to optically reproduce printed media for storage and retrieval. That said, some commercial films have leaked into the market advertised as, "High Definition." Films like Gigabit (sounds high tech), Bluefire Police (sounds official), Technical Pan (sounds technical), and Adox CMS 20 (sounds weird) have long been available to photographers. However, you pay a premium for the film and (often bundled) developer. Here we will use plain vanilla, reference librarian grade microfilm to get similar results.
Why and why not use microfilm? Microfilm Pros: 1. Its fine grain,
ultra-fine grain, super-ultra-fine grain depending on which hyperbolic advertising you believe. Grain is the "noise" of the film world. Meaningless data that gets incorporated into the image. As you can imagine, film that is designed to record information, grain is a bad thing. So microfilm is about the finest grain films you will encounter this side of some esoteric holography film. Many films embrace grain and do it well (e.g. Tri-X Pan), but microfilm is not one of them. If you are into blowing up your film to mural size, microfilm is for you. 2. Its cheap.
Professionals wouldn't trust slightly outdated microfilm with their precious, precious information. So there is little demand for outdated microfilm which leads low, low prices. I recently bought 3000 feet of 35mm microfilm for about $40...delivered. Put into more familiar terms, that is about $0.07 per 36 exposure roll. Outdated....yes, but this type of film deteriorated very little over time. 3. Longevity.
Microfilm is designed to last for a guaranteed 500 years. Well, any properly processed black and white film will probably do the same, but is not guaranteed. Since most corporations won't last 500 years, its a good bet for microfilm manufactures. Think of that next time you are looking for a 500 year old disc drive to retrieve your digital photos! Microfilm's (many) Cons: 1. It is slow.
Most modern microfilms can be successfully rated at 25 ISO. No problem when microfilming, but for general photography, it will lead to slow shutter speeds and large apertures. Not too much of a problem if you own a tripod and like bokeh. It should be noted that some pictorial films are this slow as well. On the plus side, slow films last much better over time, so microfilm is usually just fine decades "out of date." You can also get microfilm duplication film designed to make working copies of your microfilm. Since these are exposed in the lab, they are very slow. I'm talking ISO 1! About as fast as photographic paper. Although limited, you can still use this type in camera on a nice sunny day with a fast lens. 2. It is contrasty.
When you only have to resolve black print on white paper, high contrast is beneficial. Luckily there are ways to tame the contrast, however the contrast will always be "compressed" compared to most purpose built black and white films. Some people actually like the either all black and all white world of high contrast photography....for those, microfilm is a definite plus. 3. It is unperforated.
Microfilm is (usually) designed to use all the film area of the film with no allowance for sprockets. However, most cameras these days need sprocket holes to position the film correctly. Luckily, some cameras can take unperforated film just fine. 4. It has a clear base.
This increases the contrast of the film, but also makes it great for 35mm slides, if you are into that sort of thing. 5. It has minimal antihalation
properties. Antihalation prevents light from bouncing off the rear of the film or the base plate and reentering the film to make additional exposure. Pictorial films have this in spades, but microfilm has just enough to get by. This can lead to some "light piping" and weird halos in your exposures. 6. Its black and white only
. Color microfilms do exist, but they are rare and expensive. If you are buying microfilm, it is probably black and white microfilm. 7. Odd tonality.
Even though most microfilm is panchromatic (sensitive to all colors of light), it renders colors as grays in a fashion unlike regular black and white film. Not to say the tonality is unpleasant, just different. For most exposures, you will not notice, but with skin tones you might see some differences. Duplicating microfilm can be totally orthochromatic (sensitive to blue/green) to only blue sensitive. Since it does not "see" reds, they are recorded as black. On the plus side, you can work with them using a safelight. On the down side, your photos will look like they were taken in the 1930's (white skies, black lips).