Questions about color photography

All three questions are included in the following.

The types of film are divided into black and white and color, and color film is divided into color reversal film and color negative film. Photographers can choose different types of films according to their needs.

For the image used to make printed matter, color reversal film should be selected when shooting to meet the high requirements of plate making and printing. Color reversal films are divided into two types: light type and daylight type. When shooting under natural light or flash light, you should choose the sunlight type reversal film. When shooting under indoor incandescent lamp or photographic iodine tungsten lamp, you should choose a light reflector. When used in sunlight, light retroreflective sheeting will produce a severe blue image; Sunlight retroreflective sheeting will produce yellowish and reddish images when used under incandescent lamps, which is a good way to obtain warm color images. If you need to make photos, you should choose black and white panchromatic film or color negative film when shooting. Black-and-white manuscript chart remake and black-and-white slide show can choose black-and-white positive film. In black-and-white photography, if you shoot outdoor buildings or scenery with infrared film, you can get a picture with gray tone.

For people, landscapes, buildings and products, we can choose medium-speed film or low-speed film to obtain a picture effect with fine particles, moderate contrast and high definition. When shooting some still objects, if the indoor light conditions are not ideal, you can choose medium-speed film, fix the camera on a tripod, use a wide-angle lens and expose it under a low-speed shutter with a small aperture, and you can also get a picture effect with high definition and ideal contrast. When shooting scenery and buildings under outdoor sunlight, you can choose low-speed film to get a picture with fine particles and moderate contrast. In dim light such as stage performances, sports competitions and news scenes, you can choose high-speed films and ultra-high-speed films. Using ultra-high speed film will produce pictures with coarse grains and low contrast.

Professional and amateur films

All kinds of movies can be divided into professional and amateur types. Professional film is different from amateur film in photographic performance, film preservation and color reproduction.

The box of professional film is marked with the word "professional". Professional film manufacturers use mature emulsion in the production process, and the film directly produces ideal color effect after shooting and developing. Professional films are distributed by professional photographic materials stores and kept at low temperature. The validity period of professional films is shorter than that of amateur films. From the comparison of the results after shooting and developing, the photographic performance of professional film is better than that of amateur film in contrast, latitude, color saturation and granularity. Of course, its price is higher than amateur film, which is mainly used by professional photographers.

Amateur film, also called ordinary film, is used by amateur photographers. Considering that amateur films will be stored in shops and photographers for a long time, and the interval between film leaving the factory and developing after shooting is long, manufacturers all use photographic emulsions that are mature after leaving the factory to extend the validity period of films as much as possible.

For architectural photography, advertising photography and other photographic creations with strict requirements on color reproduction and high quality of photo production, you can choose professional film; You can choose amateur movies to record general family life and travel scenery.

Preservation and effectiveness of film

When the film leaves the factory, it is marked with the film validity period, which means that the photographic performance of the film emulsion is relatively stable, usually two years. Pay attention to the expiration date when buying film. The expiration date of the film is printed on the film box.

For films that can't be used up after purchase, they can be stored in the refrigerator; Take it out the day before use and let the film preheat before use. Do not take it out and use it immediately. Otherwise, the film will "sweat" and affect the imaging quality. The film should not be stored at high temperature, which will affect the photographic performance of the film and shorten the validity period. If the film is stored at high temperature for a long time, the haze will increase obviously, the contrast will decrease, and the tolerance and sensitivity Ul will also be affected.