Crop factor is a term that added toa dictionary of photographic terms, the emergence and widespread use of cameras of the new generation. With the development of modern innovative technologies, more and more digital SLR cameras with the cost available to non-professionals began to appear on the market. Such buyers, besides the price, distinguish unless another category for which the camera is chosen is the number of megapixels. With the megapixels, they have somehow figured out and, dimly imagining what it really is, they still understand that the more of them, the better the device. However, as it turned out, another important characteristic that distinguishes the quality of digital cameras among themselves is the crop factor. Before you buy a camera, you should still figure out what it is.
Few amateur photographers wondered at least onceThe question is, why, if the lens and lenses are round, do they shoot a rectangular frame? There is nothing difficult in answering this question. When projecting the photographed image onto the media in the camera, the lens optics simply cut off the “extra” part of the image, giving it a rectangular shape. It is very convenient for the production of photographic film, consisting of a number of rectangular frames, and for making photographs, giving both, compactness and versatility.
Due to years of use of filmPhotos frame size on the film continue to apply as a reference size. No one even comes to mind to change it even now, when shooting on film is almost a thing of the past. Nowadays, with the accession of digital photography, shooting is carried out on a special matrix, which can be conventionally compared with a film.
Matrix that fits in sizefilm frame, called full-length. However, most digital SLR cameras have matrices with a size significantly smaller. Naturally, on such matrices only the central area of the image is impressed, which could get onto the full-size matrix. Visually, it looks as if the frame is photographed by a lens having a much greater focal length.
Hence the term defining "increase"focal length, which actually does not occur, because here, as in our example with round optics, the outer part of the frame is simply cut off. In English, the word “crop” means “cut off”. From here and the name of the term - a krop-factor which designates such artificially increased focal length. This accurately describes how the shooting process actually takes place, since in the physical sense the focal length of the photo lens has not changed, but only the angle of view has changed.
So, the frame size of 35-mm photographic film24x36 mm was and remains the reference, with which the Crop factor is now associated. For such a frame, it is 1. At the very beginning of the digital photography era, Nikon wisely decided that digital SLR cameras could be produced with the ability to use old optics with them, which were made for decades and often cost more than the cameras themselves.
However, problems have arisen with the implementation of this idea. Create a full-size sensor turned out to be too expensive, but in very very small there was no point.
As a result of research, a sensor was createdwhich diagonally was one and a half times smaller than a frame of a 35-mm film. Thus, for such a sensor, 1.5 is its crop factor. Canon, by the way, later found an even more optimal solution. The crop factor of his cameras began to equal 1.6.
To somehow differ from it, its crop factorNikon began to call the DX, and the full-size FX sensor. This encoding continues to exist now. It is used by many other companies besides Nikon.
Manufacturers of cameras with a crop factor,used the fact that the area of their sensors decreased by more than half. This allowed to save on the manufacture of powerful and expensive optics. Manufacturers began to mass produce digital cameras that are available for a wide range of amateur photographers.
