Well, I can tell you how I scan. I have a Epson Perfection 4490 photo scanner, I use it in professional mode which gives me control over all it's functions. I scan a @ 600dpi minimum and the file output is jpeg but some prefer png for better image correction in photoshop or other image editing program. I use the histogram adjustment and tone correction functions to adjust light, dark, contrast gamma etc etc. Histogram has input functions which are eyedroppers in my program. For dark, grey and light tones of the image. For dark I usually pick the darkest area I can find usually near the eyes, the pupil or eyebrows but sometimes any dark area will do. It's just a matter of trial and error to find the right look. Light is the same method, but finding the lightest area and normally I will pick either the highlight in the eye or the white of the eye. But again any white spot might do and again it's trial and error. Tone correction has linear, lighten, darken, flat contrast, high contrast, open shadow and a few of my own settings. Again it's a matter of trial and error to see what you like and don't like. Then it's a matter of adjusting your scanning area to minimize the amount that may have to be cropped out later. I also have unsharp mask and descreening filters that attempt to minimize the moire effect from scanners. Some folks don't use the descreening filter and let their image editing program deal with it. My suggestion to you is scan it, post it, and let the photoshop pros do the editing.