Electronic viewfinder
From Free net encyclopedia
An electronic viewfinder or EVF, is a viewfinder where the image captured by the lens is projected electronically on to a small miniature display for the purposes of lining up the camera on the object to be photograhed.
Operation
The sensor records the view through the lens, the view is processed, and finally projected on a miniature display which is viewable through the eyepiece. Electronic viewfinders in digital still cameras are very similar to those in video cameras.
Electronic viewfinders in still photography
Electronic viewfinder has the following advantages over opticals viewfinders:
- Lack of parallax, without the need of bulky reflex mirror. Cameras with a separate optical viewfinder show the scene from a different viewpoint from that of the camera lens.
- Information about the scene, such as a histogram, can be overlaid with the scene.
- EVFs can show an approximation of the final exposure when they are exposure-priority.
- EVFs can show a low-light scene brighter than it is when they are display-priority.
- Most EVFs show 100% coverage of the final image.
Electronic viewfinder has the following liabilities (2005):
- There is a noticeable lag between the changes in the scene and the electronic viewfinder display.
- The resolution of the display is too low to allow accurate manual focusing.
- In low light conditions, the EVF displays which do not auto-gain can be virtually blank, making it difficult to use.
- The electronic viewfinder has a high power consumption.
Many professional photographers and advanced amateurs prefer digital single-lens reflex cameras which do not currently feature electronic-viewfinders.