Fri 30-Nov-12 07:29 PM | edited Fri 30-Nov-12 07:35 PM by Chris Platt
"Why not just try to get the underlying exposure right?" "Is it just an experience thing?"
You can certainly just try to get the underlying exposure right. Very often (most of the time?), the camera's exposure solution is the right one and you don't need to compensate.
As suggested in another post here, when in matrix metering mode, the camera can employ Nikon's very sophisticated scene recognition system to compare your scene to an internal database and deliver its own compensated solution. I.e., the camera's exposure solution when using full matrix metering may be different than the exposure solution when using center weighted or spot metering or that you might get from a hand-held exposure meter.
If you know from experience or study, that the camera's "right" solution is not going to be what you want there are several approaches to adjusting that solution. One way would be just to use manual exposure. In that case you will be able to see the camera's recommended setting through the viewfinder and you can adjust the shutter speed or aperture either way to get the exposure solution you want - but you are still "compensating" for the camera's recommended solution.
If you want to stay in automatic exposure mode and are not using matrix metering, there may be a higher probability that you will want to use the compensation dial, but knowing that you can also adjust exposure in post processing, you may decide that exposure compensation at capture isn't necessary. In post processing you can also adjust mid-tones, shadows, and highlights separately.
There are many routes to the "right" exposure both before and after the shutter is pressed. It takes study and experience to know what you want to do and even then, there may be trial and error. Fortunately, experimenting is fun.