You could brighten the video a bit, it would help to see. I dunno how you capped the video, but if you used cl_Avidemo, then setting r_intensity a bit higher helps. Also, if you do that, be sure to add some brightness and contrast when rendering the outputted frames to a new video too. If you used fraps, then you'd probably have to do a second encoding to add in some brightness.
Also, a handy thing might be to narrate your videos so that the people watching might want to know how you did some of the stuff too. That way you could maybe pause the live video to explain something, or to highlight important things for the player.