Search results
Results from the WOW.Com Content Network
Different kinds of camera lenses, including wide angle, telephoto and speciality. A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses (compound lens) used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.
Mirrorless interchangeable-lens camera. Similar to a digital single-lens reflex camera, but having an electronic or rangefinder type of viewfinder in place of the mirror and pentaprism, to allow a more compact design. See also EVIL camera. MTF: Modulation transfer function. A technical measure of the ability of a lens to create a finely ...
In other words, a real image is an image which is located in the plane of convergence for the light rays that originate from a given object. Examples of real images include the image produced on a detector in the rear of a camera, and the image produced on an eyeball retina (the camera and eye focus light through an internal convex lens).
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.
Until recent years, focusing of a camera lens to achieve a sharp image on the film plane was achieved by means of a very shallow helical thread in the lens mount through which the lens could be rotated, moving it closer or further from the film plane. This arrangement, while simple to design and construct, has some limitations, not least the ...
Zoom lenses (i.e. lenses of variable focal length) involve additional compromises and therefore normally do not match the performance of prime lenses. When a camera lens is focused to project an object some distance away onto the film or detector, the objects that are closer in distance, relative to the distant object, are also approximately in ...
Many lenses include scales that indicate the DOF for a given focus distance and f-number; the 35 mm lens in the image is typical. That lens includes distance scales in feet and meters; when a marked distance is set opposite the large white index mark, the focus is set to that distance.
For a lens projecting a rectilinear image (focused at infinity, see derivation), the angle of view (α) can be calculated from the chosen dimension (d), and effective focal length (f) (f is defined as the distance of the lens with respect to the image plane. For a thick lens, it is the distance of the rear principal plane of the lens w.r.t the ...