overlaying a "transparent" clip darkens the underlaying clip
by Arthur
on
Jul 10, 2006 at 5:07:41 pm
I just noticed this after using the Virtual Dub subtitler plugin (through Wax) on a track: the plugin darkens the video.
The darkening is not noticable in the Vegas Preview window, but you can see it in the external monitor, and after print to tape.
After some tests I found out that I get the same amount of darkening if I just put a solid color (with alpha set to zero) on the track above my video. So it seems it the problem lies not with the subtitler plugin, but that anything with full transparency darkens the underlying clip.
It makes no difference if alpha is set to 'straight' or 'premultiplied'.
Any suggestions on what is going on here, and how to avoid that?
