Search results
Results from the WOW.Com Content Network
A lens with a focal length shorter than normal is often referred to as a wide-angle lens (typically 35 mm and less, for 35 mm-format cameras), while a lens significantly longer than normal may be referred to as a telephoto lens (typically 85 mm and more, for 35 mm-format cameras). Technically, long focal length lenses are only "telephoto" if ...
Diagram illustrating the flange focal length of an SLR–type and a mirrorless–type camera. For an interchangeable lens camera, the flange focal distance (FFD) (also known as the flange-to-film distance, flange focal depth, flange back distance (FBD), flange focal length (FFL), back focus [1] or register, depending on the usage and source) of a lens mount system is the distance from the ...
f-number. Diagram of decreasing apertures, that is, increasing f-numbers, in one-stop increments; each aperture has half the light-gathering area of the previous one. An f-number is a measure of the light-gathering ability of an optical system such as a camera lens. It is calculated by dividing the system's focal length by the diameter of the ...
How focal length affects photograph composition: adjusting the camera's distance from the main subject while changing focal length, the main subject can remain the same size, while the other at a different distance changes size. The two fundamental parameters of an optical lens are the focal length and the maximum aperture. The lens' focal ...
How focal length affects perspective: Varying focal lengths at identical field size achieved by different camera-subject distances. Notice that the shorter the focal length and the larger the angle of view, perspective distortion and size differences increase. Lenses are often referred to by terms that express their angle of view:
For cameras that can only focus on one object distance at a time, depth of field is the distance between the nearest and the farthest objects that are in acceptably sharp focus in the image. [ 1] ". Acceptably sharp focus" is defined using a property called the "circle of confusion". The depth of field can be determined by focal length ...
Depth of focus. Depth of focus is a lens optics concept that measures the tolerance of placement of the image plane (the film plane in a camera) in relation to the lens. In a camera, depth of focus indicates the tolerance of the film's displacement within the camera and is therefore sometimes referred to as "lens-to-film tolerance".
For example, a 28 mm lens on the DSLR (given a crop factor of 1.5) would produce the angle of view of a 42 mm lens on a full-frame camera. So, to determine the focal length of a lens for a digital camera that will give the equivalent angle of view as one on a full-frame camera, the full-frame lens focal length must be divided by the crop factor.