Edge effect photography

Some density distortion in the image is caused by local drug interaction during cleaning, which is called edge effect. This is also called proximity effect, or boundary effect. This effect occurs at the boundary of two areas, which are exposed to different degrees of radiation, thus producing different degrees of chemical activity during the washing process. Usually, the edge effect is due to the penetration of exhausted developer or inhibitory by-products into an area, which reduces the chemical activity. In these two areas, it is exposed that the development is increased at the edge of that area, which produces a very thick density, which is the so-called "Mackey line". When the Mackey line is at the two edges of a very narrow * * * same area-or when this line surrounds the inner edge of a very small point-the Mackey line merges to produce a comprehensive density, which is the so-called "eberhard effect". The decrease of development between the edges of two areas with basically the same exposure is called "Cosinski effect". This phenomenon is manifested in the obvious displacement between the two images, or the narrowing of the images of objects (such as parallel lines) in very close positions.