Russ,
I noticed something looking at your post. The histogram in the upper right corner of your 498 image opened in Camera Raw reveals something. (I’m assuming that is the histogram of the image right off the scanner) If you notice the image looks kind of “flat”, or low contrast. Looking at the histogram shows your black point (shadow) in the original scan needed to be set to the right (or a higher value). As dark as it seems, your image is not all the way to a value of 0 on the shadow side. That made the image scan with a lower contrast. It looks like you bumped up the contrast in the levels adjustment, but getting it right in the original scan will always yield better results.
The single most important setting in scanning , is to get the black and white points set correctly. Each image will have a unique set of these, and is the reason that batch scanning on one setting is a poor compromise at best. The shadow point (on the left in most histograms) and the highlight point (on the right in most histograms) show the lowest and highest density. If you don’t adjust your scanner to these points in the scanning software, effectively you are not using the full capability of the scanner. Setting these points is somewhat of a trial and error process. You have to at least do a preview scan. Then using the histogram produced by the preview, move the black and white points to the ends of the histogram. The scanner has 256 levels of exposure available. If your image has say, only 240 levels, you can move the shadow-highlight points so that when the 240 level image is scanned, it is scanned with all 256 levels available in the scanner. Also, if the overall image is dark, after the black and white points are set, then you can adjust the gamma/midpoint/brightness (all three terms are used at times) to lighten or darken the image to suit.
Those steps will help ensure that you get the most you can out of the scanner. Keep in mind that any editing done after the initial scan will always be removing something from the image. By maximizing the scan quality it will also tend to minimize the amount of editing needed.
Edited 4 time(s). Last edit at 01/30/2015 08:16AM by jgunning.