Light Meter/Exposure Compensation

Derek Zoolander · Feb 12, 2009

Are those 2 the same thing when I look into my viewfinder? I looked in my manual and I don't actually see "Light Meter" in the index. And what I thought would be the light meter, is actually called Exposure Compensation. The line that goes back and forth depending on how bright it is...

mrodgers · Feb 12, 2009

The display you are refering to is just that, a display. When in a semi-auto mode (Aperture priority, Shutter priority, or Program shift) it is the display for the Exposure Compensation. The semi-auto modes will always try to expose at the center of what the light meter reads. Exposure compensation is just telling the camera to shift the exposure that it's reading to that amount you set.

In manual mode, there is no exposure compensation. You set the exposure completely with full control over everything. The display now shows what your light meter is reading and you adjust aperture, shutter, or ISO to change the exposure. Change any of those and the display will move.

What I don't know is if there are more than one display with a dSLR. Perhaps the exposure compensation display is on the LCD and the display in the viewfinder is only showing what the light meter is reading. I am only assuming that the display in the viewfinder is the exact same function as the one on the back LCD with what I typed above.

Derek Zoolander · Feb 12, 2009

So that moving image at the bottom of the display is the light meter then? when im in manual, it jumps back and forth from + to - depending on the darkness or lightness of what im point at...

wish someone could post a picture of what they are looking exactly when they say they are looking at their light meter...

Big Mike · Feb 12, 2009

That 'scale' (along with the shutter and aperture settings) is what people are looking at when they say they are checking the meter or taking a reading etc. (unless they have a hand held light meter).

In any of the auto modes, the default is for the 'needle' to be on the --0-- (the camera changes the setting to make it so). But you can use exposure compensation to move the needle away from --0-- (which changes either the shutter speed or aperture).

If you put the camera into manual mode, it does not adjust the settings at all...so the needle will likely not be on the --0--...it might not even be on the scale at all.
A basic starting point when shooting manual would be to adjust the settings until the needle does hit the --0--. This would give you the same exposure as the auto modes.
(you would need to do with with the camera pointed at the scene).

Now, the key point here is that you don't have to take your shots with the needle on the --0--...you can choose to have it above or below that centre mark. In manual mode, you simply change one of the settings...but in auto modes, you would need to adjust the exposure compensation.