Woody is correct about keying

Woody is correct about keying with older gear. I used to do it a lot with miniDV footage and never had any problems. Very important things to consider are how the screen and talent are lit as this makes a LOT of difference in the keying process. The tool(s) used make a difference too as some are better than others. Telling us what editing software you're using will be of some help for us to help you.

Mike