Why don't many photography agencies send negatives?

Because normal international practice should not be given free of charge, but at present our laws basically support giving, but the laws are still vague. It can also promote secondary consumption.

In reality, charging by piece is more often a helpless choice to increase sales and lower the shooting threshold. If it is a single person shooting, it takes hundreds or even hundreds of dollars to shoot a group of video photos, but for the long-term operating costs of photography institutions, if it is not daily business, there is almost no net profit.

Although negatives are of little use to photographers, if they are all given away for free, it means that the whole photography service is only worth a little money, which destroys the market value of photography service. Personal commercial photography is not like the rapid consumption of catering and other industries, and it can accumulate income. A small amount of photography consumption with extremely low frequency has a low starting price, and even with secondary consumption, it is difficult to offset the cost.

This is just to maintain the market value that is easy to fall with the meager income of a long stream of water. And the main difference of some photography packages is the number of negatives. If you send them all, it makes no difference, and no one will buy an expensive set meal.

Main information:

The negatives were also translated into movies. At present, the widely used negative film is coated with silver halide on the base of acetic acid film. When light shines on silver halide, silver halide becomes black silver, which is fixed on the film base after development and becomes a common black-and-white negative. Color negative is coated with three layers of silver halide to show three primary colors. In addition to negative films, there are positive films, one-time imaging films and so on.

In PCB terminology, the meaning of negative often refers to black and white negative. As for the brown "azo film", it was named by another photographic tool. The negatives used in PCB can be divided into "original negatives" and "working negatives" after copying.

Film sensitivity (ISO) refers to the data of the International Lighting Organization, and film ASA refers to the abbreviation of American Standards Institute. ISO and ASA refer to the same data.

Films are classified according to photosensitive speed, from the lowest ISO 25 degrees to the highest ISO 3600. According to the film size, there are 120 (large negative), 135 (most commonly used), 1 10, etc. , and 8"X 10 "large negatives for shooting advertisements or large posters.

According to the type of photosensitive film, there are black and white film, color film and infrared film.