filmscanners: Photoshop Curves vs Levels

[Alan Womack <arwbackup@worldnet.att.net>]

Last couple of days I was working on a scan from my ScanWit from Fuji Super G 
400 of my 2 year old son playing with his trucks.  I had used a couple of flash 
units and screwed up the light level a bit and certainly the background shadows.

The local minilab printed crap, but the expression was cute..  So into VueScan 
I went, aweful.  Color balance wouldn't come close, way too blue.  Also there 
was bad posterization in highlights from his face.  I went to MiraPhoto and 
found I couldn't control where it placed the actual highlights what so ever, it 
was mapping the brightest part (those skin reflections) up to 255.  Obviously 
this wouldn't work.

I took a look at a RAW scan from VueScan in PS and found there was a difference 
in skin values or maybe 3 RGB and way too much blue.  7-10 points more blue 
than red, which is typically in my children 30-40 below red when skin tones are 
in the low 200 range.  (the Raw scan was in the 37 to 41 range)

I then took up a curve that was nearly straight up to move my highlights in tke 
skin into the  200 neighborhood and spent another couple hours fixing the skin 
tones.

So my question is:

Is there a fundamental difference between using levels to stretch the histogram 
versus using curves to stretch the same with a very steep line?

alan