flitcroft

If this wasn't answered, EV means "exposure value". EVs are relative numbers that are really only useful, with today's camera technology, in saying that a certain combination of settings will produce an exposure "one stop (one EV) lower" than another combination of settings. For instance, if a portrait is properly exposed at 1/125s shutter speed and f/11 aperature an exposure of f1/125s and f/8 is one EV higher (since the larger aperature lets in more light to the sensor). There are assigned numbers for these levels but with every camera having a decent internal light meter they aren't particularly useful to memorize.

When you see a camera with "+/- 2 EV" it is probably referring to the range that camera will bracket its exposures for you. Bracketing is when the camera exposes three frames for you: one at what it thinks is the correct exposure and then one each of a higher and lower EV that you can specify before you take the photos (in half-EVs or 1/3 EVs on better cameras). This function is useful when you don't have a graduated neutral density (GND) filter and you have part of a photograph that is in shadows and another part that is bright. Cameras cannot get both right without some tricks so you have to either use a filter to darken (only) the bright part of the image or combine two differently exposed photos in Photoshop. Obviously, this technique works best with still subjects and a tripod or the results will look off.

More on EV and LV (light value):
http://www.kenrockwell.com/tech/ev.htm


When are we going to have a photo meet?