Good stuff David. And I agree with Aaron, whether film or digital, under exposure is always better than even relatively slight over exposure. When over exposed, highlights are normally lost forever, and shadow areas merge with mid-tones, with saturation often beyond control - the image is burnt out.
With under exposure however, although still undesirable, the greater majority of an image can be rescued, by exposure and grade of paper when printing film, or by Gamma Correction, Contrast, Brightness and Saturation controls in photo-editing programmes.
It's still not a perfect solution, but at least an acceptable finished product can be achieved. I know - I've had to sue this recently, as I become accustomed to the various settings on my Nikon!