Choosing the right film

Before taking pictures you'll want to select the kind of film you plan to use. Do you want color or black-and-white photos? Prints or slides? Kodak offers a variety of films for 35 mm cameras. This section describes the characteristics of several Kodak films. Knowing the characteristics of these films will help you select the best one for the kind of pictures you want to take.

Color slides vs. color prints

There are a lot of different Kodak color films to choose from, but all of them fall into one of two categories: color slide films (also called transparency or reversal films) and color print (or negative) films. Color slide films are direct positive films; that is, the film that goes in your camera and the slides you get back are the same film. With color print films, the film that goes in your camera is processed to a negative that the processing lab enlarges into color prints. Which is better? It depends on your needs and your tastes, and also the particular shooting situation. First, consider your preferences. By far the majority of amateur photographers use color print (negative) films because they are so convenient. With print films, you get back fairly large prints that are easy to view and can be readily shared with others or stored in an album for future viewing. Print films yield excellent enlargements and can be transferred onto video tape. Color slides are used mainly for projection or viewing in hand-held viewers, but you can also use them to make color prints and enlargements, or have them transferred to video tape. Color slides are also less expensive, since no printing stage is involved. If your primary interest is in giving slide Shows, use color slide films.

Each type of film also has technical characteristics that may make one or the other better in a given situation. Color slide films, on the whole, are more contrasty and can therefore add more snap to dull or low-contrast scenes. Correct exposure is also much more critical with color slide films. Color negative films, on the other hand, can record a wider contrast range and allow greater room for exposure error.

Film speed

The film speed indicates relative sensitivity to light. Film speed is expressed as an ISO number or an exposure index (EI). The higher the speed, the more sensitive or faster the film; the lower the speed, the less sensitive or slower the film. A fast film requires less light for proper exposure than a low-speed film. For example, a film with a speed of ISO 25 is slower-requires more light than a film with a speed of ISO 200. To find the speed number for your film, look on the film carton, in the film instructions or on the film magazine. You set the film speed on exposure meters on cameras with built-in meters to obtain the correct exposure. Some cameras automatically set the film speed by reading a code on DX-encoded films.
ISO speeds have replaced ASA speeds. ISO speed numbers are numerically the same as ASA speed numbers. For example, if the speed of a film is ISO (ASA) 200, you would set 200 on the ISO (ASA) dial of your camera or meter.

Film grain and sharpness

Two important aspects of image quality related to film speed are sharpness and graininess. Sharpness refers to the film's ability to record fine detail with good definition. Generally, the lower a film's ISO speed, the greater its ability to render subjects sharply. Graininess is the sand-like or granular texture sometimes noticeable in prints and enlargements. Grain is a by-product of the structure of the films light-sensitive emulsion. It is more apparent in pictures made with faster films. As speed increases, so does the size of the grain pattern.

Enlargement of the negative also affects apparent sharpness and graininess. At moderate print sizes (5 x 7-inch or smaller), grain is barely noticeable, even with fast films. But as enlargement increases, graininess becomes more apparent, and image sharpness diminishes. If you're planning on making extreme enlargements, you'll get the best results with low and medium-speed films.

Recent improvements in film technology, such as the KODAK T-GRAIN Emulsion, have minimized the problems of graininess, even with very fast films and at high degrees of enlargement. Most Kodak films now take advantage of this new technology in some or all of their image-forming layers.

The relationship of film speed to grain and sharpness sometimes forces you to make crucial quality decisions. With action subjects, for example, you have to decide if you want to use a slower film for sharper finer-grained pictures or a faster action-stopping film. If you opt for slower-speed film, you'll lose some action-stopping ability; but if you choose a faster film to stop action, you'll get increased grain.