The bit depth or color depth of a digital image is the number of binary bits (bits) used to encode the color of a single pixel.
It is necessary to distinguish between the terms bit per channel (bpc – bits per channel) and bit per pixel (bpp – bits per pixel). The bit depth for each of the individual color channels is measured in bits per channel, while the sum of the bits of all channels is expressed in bits per pixel. For example, an image in the Truecolor palette has a resolution of 8 bits per channel, which is equivalent to 24 bits per pixel, because the color of each pixel is described by three color channels: red, green and blue (RGB model). Continue reading
Diffraction is an optical phenomenon that limits the sharpness of a photograph while reducing the relative aperture of the lens. Unlike other optical aberrations, diffraction is fundamentally unremovable, universal and equally common to all photographic lenses without exception, regardless of their quality and cost.
Diffraction can only be seen at 100% magnification. Notice how the image becomes less and less sharp with increasing aperture.
With the passage of light through the aperture, the bulk of the light waves continues to move rectilinearly. However, those waves whose path lies near the very edge of the diaphragm deviate from their original direction, trying to go around the obstacle that has arisen on their way. The smaller the size of the aperture Continue reading
A scatter spot (circle) is a distorted image of a point projected by a photographic lens onto the camera’s matrix or film. These distortions are caused, firstly, by structural factors, i.e. natural imperfection of optics and photosensitive material, and secondly, functional reasons, and above all – selective focus. An image of an infinitely small point can be a point only when it lies strictly in the plane of the matrix or film. If the image of the point is out of focus, the point turns into a blurry spot of rounded shape, the size of which increases with distance from the plane of the ideal focus (see also “Bokeh”).
Formation of a scattering circle. Continue reading