-100% Rule: determine what the tightest framing of a picture will be without scaling the picture above 100% in FCP or AVID.
-open the picture in photoshop
-make the Info palette visible
-set options to Pixels
-select the Marquee tool
-eyeball different zooms on the picture using Marquee
-on the info palette read the width of your tightest framing.
-devide 1920 by that number
-in my example 1920/987=1.9
so I know I have to blow this picture up about 2x to be able to zoom in as far as I want.
-Image > Image Size
-Enter the new number for Width
-Check Scale Styles
-Check >Resample Bicubic
-Resolution > leave unchanged