Things that are crucial in pics:
1)Lines of resolution..typically your average vidcap is not going to give you the lines of resolution than a digital camera can give you.
2)SIZE of frame..640x480 is always going to look more washed out than say a 320x240 or 352x240 vidcap. Sometimes smaller IS better.
3)Manipulating..make sure you use good editing software that allows for adjustment of color balance, sharpening and brightness/contrast. It's amazing how you can take a pretty crappy pic and really make it look almost brand new!

IF you have Vegas Video, you can do so many things with regular pics or vidcaps that I just can't recommend this software more than I have already.
If you're going to be serious about videos & pics, it's definitely worth the cost of investment.

Snagit does a good job, and another piece of software I've used for 4 years now is Ulead's PhotoImpact..again, a great tool for manipulation.