Viewfinder

The viewfinder is a device on a camera used for framing and focusing the picture.

In photography, cameras come with three basic types of viewfinders:

• TTL viewfinder (classic SLRs) - features a system of mirrors and a prism and allows you to see precisely what the lens projects onto the sensor
• EVF viewfinder (mirrorless interchangeable-lens camera, SLR EVF) - shows the same view as the lens, but the image is projected onto a tiny LCD within the viewfinder; generally weighs less than the TTL viewfinders, the image quality depends on the display and its resolution
• Optical viewfinder - an eyepiece with simple optics; the image is an approximation of what the lens sees, but you can preview the image on the display. The more advanced devices let you control other functions such as zoom, switching between video and photography, and various other settings.