Introduction What is photography? The history of photography What this site will do for you Light: The most important element Why light is important to a photograph The many types of light Controlling light in your pictures The camera The basic function Types of cameras Choosing the right camera Putting the image together: the Lens How the lens bends light: a tutorial A brief introduction to apertures The variety of lenses Choosing a lens Exposure: a film tutorial How film records an image Understanding film speed Print vs. Slide film Film recommendations Taking Pictures Depth-of-field Apertures and shutter speeds Composition and experimentation: the basics Metering: when you can't guess The many types of picture-taking Photography with a point-and-shoot Accessories Tripods: for when you can't stay still Lens filters Post-processing: after development Scanning photos The digital darkroom Photo and equipment storage
If you look at the box of a package of film, it might say something like "ISO 100" on it. ISO 100? What does that mean? Is it important? Yes, it is very important, because it tells alot about the film. The ISO is the film speed, or how sensitive a single roll or sheet of film is to light. If the ISO is at 25, it is considered slow, or is not very sensitive to light. Because of this, it cannot work in very low light. However, ISO 6400 film is extremely light-sensitive, and can work in any type of light, including at night. So which film would you choose- ISO 25 film, or ISO 6400 film? If your first answer is ISO 6400 film, you would be wrong in quite a few ways. First of all, film is made up of tiny crystals, called silver halide crystals. The faster the film, the larger the crystals, and the grainier the film. Take a couple examples of fast films: Kodak Gold MAX 800 and Kodak Royal Gold 1000. Both can work in very low-light, and most of time people don’t complain about grain. Those people who don’t complain never enlarge their pictures beyond 4x6 or 5x7. If you tried blowing up ISO 1000 film to 8x12, the grain would be dreadfully obtrusive. So, just sticking with the fastest films wouldn’t be a good idea.
The world’s best films are usually in the range of ISO 25-100. These films have very fine grain, and superb sharpness. The color in many of these films (Especially Fuji Velvia, an ISO 50 slide film) is incredible.
Setting your camera to the proper ISO
Once the film is loaded, you will need to set your camera to the correct film speed (this should be printed somewhere on the box or roll itself). This can be accomplished be setting a mechanical or digital ISO dial.
In newer cameras, there should be a feature called DX Coding, which allows the ISO dial to be adjusted automatically. This is done by reading a code on the film, which tells its ISO.
So, which film speed should I stick to?
Keep a little bit of each film speed, since you do not know what conditions you are going to be in. It is safe to say that you should have ISO 100 or 400 film for all-around use. The film is fast enough for taking pictures indoors, and the grain is small enough that you can make huge enlargements.