I finally got around doing a YouTube video, as requested by a small Finnish blues festival ( http://www.kaaviblues.com/english.html ). I must thank the other forum members for all the good advice I got, I don't think I could have made it without your help.
Anyway, here's the video, it's very basic, lo-fi, etc. but shall have to do for now.
I finally just ended up shooting this one with our cheap little digital camera, to get off the hook with the festival. The black and white looked actually nicer to me, than the colours. I think I have to give the matter a little further study, before trying again.
I put my Zoom videorecorder on a mic stand at my gig on a Berlin bar last Saturday, to see what it can do. Here's a Blind Boy Fuller tune I did that night: