what is ev?

Question

photo

Answer 1

Eh, yeah. What dollarbu said. But in practical terms... with regard the the EV button on your camera:
If you leave the EV setting on zero, you let the cameras built-in exposure meter do all the work.
If you dial in a value bigger than zero, you manually override the cameras calculations and over-expose (the bigger the number, the more you over-expose). This is something that you *want* to do with snow landscapes, bright beach scenes, etc.
And if you dial in a negative number, you under-expose. There are times when you want to do this, too. Like when your subject is a lot brighter than the rest of the scene.
Using the EV setting only works when the camera is in automatic mode, aperture priority, or shutter priority. With manual mode, you already have full control over the exposure.

Answer 2

In the olden days, it was a measure of the level of light relative to film speed, as explained (better) above. You could actually lock in a certain EV value between the aperture and shutter speed and then just twist the dial one way or the other, depending on whether you wanted a faster shutter speed or a smaller aperture. This was a way to control sharpness or depth of field for various kinds of photography.

These days, it means the same thing, but we use it differently. As OMG explained, you step up or down from the metered reading (or "recommendation") when you have reason to believe that you can outsmart the camera. You add or subtract "EV" to accomplish this.

This is just "enhancement" information and you should vote for one of the answers above as the best, because they were first.