>>Then take your shots. I've tried this before with my older camera, and I didn't actually have a tripod at the time, and improvised the stand for the extra lens from Legos... so it didn't really focus right each time, but I got good colors.
>
>Great idea! I had even thought while playing around with it in the software “it’s too bad that I didn’t know of something black in the photo.” It never dawned on me that an unexposed part of the film was the perfect black.
>I am surprised that there isn’t one set thing (or things) to do that would be right for every negative, or at least very close. After all, my scanner doesn’t differentiate between the different negatives and I think the color is right, and Randy mentioned that he likes what his film scanner does. Maybe they are smart enough to determine unexposed film and adjust. That would be pretty impressive.

My daughter has such a scanner - high class, slow and very good. I think its software gets this white balance by looking for edges of the shot and then measuring an area around it.

>I’ll try playing around with the white balance on the camera, but I won’t be able to come up with a blank frame for each roll.

You don't really have to have a blank frame - if you can zoom into a blank area an then measure the white balance there, that's it. It would also help to know where does your camera actually measure the white balance - does it take the average of the whole view, or is it center-weighed, or just a center area etc. You should usually be able to find sufficient blank space at the end of the roll. But then for those where it was just narrowly cut, you may be out of luck - finding a similar color blank strip may help to get it sufficiently close to some balance which can then be fixed by software.