http://www.rexer.com/cine/oar.htm

I always fix the pictures I know they are with wrong ratio in paint Shop Pro X.

Yes it is easier in PSP : you directly put the ratio in the appropriate field

Usually it is easier to remove black borders before trying to resize pictures to correct ratio, except in some rare cases where the ratio of picture is weird because a part of the border was really part of the picture.

In the link that you posted they mention 1.66 for european movies, it is rather 1.85 for these. 1.66 is more used for european TV-movies/series, or some "recent" US series.

Thanks Garco and antp for your advise

I have been using Media Player Classic to play the DVD and pause on the frame I want to make a screen capture of. It is easy enough to step forward by individual frame to select the best available view, but there seems to be no way to step in the reverse direction by individual frame. Is there some way to do this that I am just missing? I have been clicking as short of a distance back as possible on the little moving slider of the progress bar, but that always takes me back at least several seconds. I was just thinking it’d be a lot more efficient if there was a way I could go back one frame at a time that I was somehow overlooking.

It is annoying indeed. Unlike DVDs, with divx files you can go frame by frame in both directions, it is easier.
What I did is to assign Ctrl+Left/Right for framestep backward/forward, and just Left/Right for "Jump medium". So when I press the left key it moves of 3-4 seconds back. There is also a "Jump small" which may be better for what you want.