getting back to the histogram on the back of your camera.

As you look at it from left to right.
the very left hand side is the colour black,
the very right hand side is the colour white
on a grey scale, each channel will have its own histogram, the one on the back of the camer is
normally an averaged out grey scale of your image.
the height of the graph is the amount of that particular colour.
so looking at the histogram you can guess that the image hame more dark colours then light colours.
If you look at this one

you can clearly see the explanations for over exposing and underexposing and how the appear on the hisogram.
if you look at the overexposed one you can see that the graph is over to the right hand side and you have lost all the detail in the bright parts,
If this was your flat then you would loose all the flat detail in this area.
If you look at the OK one, again there is some over exposure on the right as the graph goes up to the right hand side.
wha you want is for the graph to go about 2/3 across the screen so that you dont loose any detail.
If you are doing a flat image then you will probably have a graph like this.

Mac.