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Film Selection

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? 

Color Slide vs. Color Print Film
Color Temperature
Processing
Film Speed
Exposure Latitude
Film Speed for Enlargements
Film Speeds
DX-Encoded Films
Film Grain and Sharpness
Versatility of Films

Color Slide vs. Color Print Film

There are a lot of different 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.

Films are available in ISO speeds 25, 50, 100, 200, 400, 800 and 1600. 100 speed film offers extremely fine grain and very high sharpness. Use it when you want high quality in a medium-speed film. 200 speed film provides excellent results for general-purpose photography. It offers plenty of speed for moderate action and some existing-light situations. 400 speed film is a multi-purpose film that offers flexibility in a variety of lighting and action situations. 800 speed film features high-speed and high image quality. It provides sharp prints under the widest range of picture-taking conditions.

Color Temperature

One other technical consideration that you should be aware of when choosing a color film is its color temperature or balance. All color films are designed to be used in a certain type (temperature) of light, and you will get the best results when you are careful to match the film to the existing light source. Using the wrong film/lighting combination will result in distracting or unattractive color casts. Daylight films used indoors with incandescent lamps, for instance, will produce pictures with an overall reddish or orange cast. Similarly, indoor (tungsten) films used outdoors will have an overall blue color.

Virtually all color negative films sold for amateur use are balanced for daylight and will yield the best results under daylight or with electronic flash (both have a color temperature of about 5500 degrees K). Because photofinishers can improve color balance when printing negatives, you can get good results with a variety of light sources, or you can filter the light source during picture-taking to improve color. Color slide films, however, are available for several different temperatures of light, including daylight, tungsten light (3200 K) and photolamps (3400 K). Since no color corrections can be made when slide films are processed, they have less tolerance for error. You should choose a slide film that is balanced for the light you'll be photographing under.

You can use slide films balanced for one type of lighting under a different type of lighting if you use color-correction filters. However you will get optimum results if you expose a particular film under the light source for which it is balanced.

Processing

Have your film processed promptly after exposure. You can process many 35mm films for general picture-taking yourself. You'll need a film processing tank, a room that you can make totally dark, an accurate thermometer, and chemicals that are available from your photo dealer. For black-and-white film, obtain the following chemicals: film developer, stop bath, fixer, and a wash solution. With most slide films, use process E-6. Process color negative films in chemicals for process C-41. 

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. Every time you double the ISO number you cut in half the amount of light necessary to properly expose the film. 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. Most cameras automatically set the film speed by reading a code on DX-encoded films.

Exposure Latitude

A film´s latitude is the degree to which it can produce a usable image even if given less or more exposure than its film speed calls for. Slide film is tolerant of underexposure; it´s best never to be more than half a stop overexposed. Print film is tolerant of overexposure; it´s best never to be more than half a stop underexposed.

Film Speed for Enlargements

The ISO or ASA value of a film corresponds to the film´s sensitivity in conventional film photography. Film with a lower ISO, such as a 25 speed film, necessitates more light to produce the same image as a film with a higher ISO like 800 speed, consequently higher ISO films are appropriate for taking high speed (or) low light photographs. Faster films are inclined to be more grainy with inferior color quality to that of slower films.

Film Speeds

Film is classified according to its measured sensitivity to light, and the scale is an exposure index of film speed numbers. The most widely used index is that adopted by the American Standards Association and the International Standards Organization (ISO). Each number in the ISO scale represents a 1/3 stop change, and the ISO doubles every third number. Each speed in bold above varies from the one above or below it by 1 f-stop. The ISO for a film indicates the amount of exposure required to produce an image of "normal" density. The higher the ISO number, the faster the film. The faster the film, the more sensitive to light it is, and the less light is required to expose an image on it. The lower the ISO number, the slower the film. The slower the film, less sensitive to light it is, and the more light is required to expose an image on it. Both contrast and latitude correlate to film speed. Films are low contrast if large changes in exposure result in small differences of density, and high contrast if small changes in exposure result in large differences of density. Films with "fast"speeds (ISO 400+) are less contrasty and have more exposure latitude than "slow" films. Since medium and fast speed films exhibit less tonal contrast than slow films, they may be more suitable for subjects that have both bright highlights and deep shadows.

DX-Encoded Films

DX-encoded films were developed by Kodak to help camera manufacturers make automatic cameras even more automatic. DX-encoded films provide compatible auto-exposure cameras with vital information about the film you're using. All of this information is encoded in a checkerboard pattern on the film magazine. When you load the magazine into the camera, sensors in the film compartment read the code.

DX-encoded films offer great convenience because they save you from having to set the film speed manually each  time you load the camera. More important, they make it impossible to set the wrong film speed or to forget to change film speeds when you switch from one film to another. Also the camera knows when it has reached the end of the roll. And by providing information about the film's exposure latitude, the DX encoding can help the camera make important exposure decisions.

DX-compatible cameras are programmed to a specific range of ISO film speeds. This range is quite wide for SLR cameras, typically ISO 25 to ISO 5000. For simple cameras, the range may be narrower. If the camera cannot read the film speed, it will typically set a default speed of ISO 100. While this film-speed range covers most ordinary films that you will be using, there may be occasions when you want to go beyond this range or when you want to set a speed that is different from the manufacturer's designated speed. In such cases, it's usually possible to set a different speed manually. Many cameras display the film speed set by the camera, so you can check that it is correct.

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. 100 speed film excels in producing big enlargements. 

Improvements in film technology, such as the T-Grain emulsion, have minimized the problems of graininess, even with very fast films and at high degrees of enlargement. Most 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. 

There will undoubtedly be times when you'll want to use a very high-speed 35mm color-slide film. This may occur when you're shooting by existing light, when you want to use a fast shutter speed combined with a small lens opening, or when you need a small lens opening to get good depth of field under dim lighting conditions. For best quality, use the normal speed rating of the film. However, if your shooting situation requires a higher film speed, you can double the rating of most slide films and ask the photofinisher to use push-processing.

Versatility of Films

While color films are designed specifically to produce color slides or color negatives for color prints, they also give you a great deal of versatility. You can have color slides made from your color negatives and color prints made from your color slides. You can also have color prints made directly from finished color prints. 

In addition you can have black-and white prints made from your color negatives, or you can make them yourself. Kodak manufactures KODAK PANALURE SELECT RC Paper for this purpose. When color negatives are printed on KODAK PANALURE SELECT RC Paper, the gray tones in the print accurately represent the tonal relationships in the original scene. When color negatives are printed on black-and-white paper designed for printing black-and-white negatives, you don't get this accurate tonal relationship. KODAK PANALURE cannot be used with your regular safelight for black and white paper.

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