I am having trouble keeping the histogram away from the sides. Even though I set to matrix and have the light meter in the middle most of the histograms are jammed up to one side or the other. What am I doing wrong? Thanks
There really isn't a "normal" histogram. What it looks like would depend upon the scene. If there are mostly dark tones, it may be more towards the left, the opposite if there are mostly light tones even with matrix metering. If you shoot RAW, keeping the histogram to the right without clipping is often recommended no matter what the scene looks like.
Are the histograms clipped or just near the sides? Show us some examples and how you metered.
I updated your post above to add the histograms for the two images.
In this case I would not worry about the histogram being pushed to the left. These are indoor shots using flash so the backgrounds are going to be dark. Your subjects are properly exposed and nothing important is lost in the shadows.
In fact lookin at the on the right side, if you had exposed brighter you may have lost some highlights. The dynamic rage of the light is greater than the camera can record. In this case it is better to sacrifice the shadows.
The right side of the histogram is usually more important than the left side. If you overexpose, histogram bumped up against the right side, there is little room for recovering those lost highlights. The shadow detail is more easily recovered, especially at low ISO.
When you have a scene like this, that has a dark background, you can use active D-Lighting to help bring up the brightness without overexposing the highlights.
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Even if you're shooting raw, there isn't much you can do about how the histogram looks in post. It's best to use the histo in the camera first to judge exposure. If it doesn't look good there, then adjust the exposure.
Use the + button on the camera to zoom into the more important areas of the image and check the histogram. If it looks good at that point, don't worry about the rest. It appears the left side of the histograms you posted are for the background.