Microprism
From Nikonians Wiki - FAQs, Photo Glossary, Good Photo Locations, Help
Jump to: navigation, search ...
Microprism
Edit Read more: Glossary, Camera parts
Edited by Awcam
View full history ...
MICROPRISM COLLAR - Focusing aid in a viewfinder screen composed of small glass or plastic multiple prisms. An image that is in focus appears sharp and clear; an out-of-focus image has a broken-up, shimmery appearance.
Microprism
Minute glass or plastic structure of multiple prisms set in a viewfinder screen to act as a focusing aid. Breaks up an out-of-focus subject into a shimmer but images a focused subject clearly.
Microprism collar is a grid type ring found in the center of a camera focusing screen, usually surrounding a split image screen.
Millimicron (mµ) is one thousandth part of a micron.
SLR microprisms and split-images are optimized for slower lenses, so you don't; get the best accuracy with faster lenses.
Poor autofocus accuracy ...
Back in the 1960s and 70s microprism viewfinders were common in SLRs. These were special viewfinder screens containing tiny prisms on the surface. These prisms would break up the surface of out of focus areas, making it easier to focus.
MicroDrive MicroDrive is the brand name for a miniature one-inch hard disk that fits in a CompactFlash Type II media card slot. Find out more.Microprism A focusing aid located in the focusing screen.
in the case of a coupled rangefinder, when the lens is correctly focused. SLR cameras may have a prismatic split-image system in their viewing screen. Works on the same principle as a microprism, and is restricted to apertures of f5.6 or greater.
using vertically arranged +/-/- light emitting diodes (LEDs) on the left side of the viewfinder to indicate the readings of the meter versus the actual camera settings. The focusing screen also has 3 mm split image rangefinder and 1 mm microprism ...
 See also: Focus, Prism, Camera, Focusing, Shutter
  
|
RSS
