Thanks Tony and jjjnettie

I am using a yellow filter because the image is always overesposed and need to lower the exposure but since i can't control exposure times in video mode on my camera, i thought i can use a filter to get less light in
@Tony, does it mean that if i take 10x20second avi movies during a period of an hour for example, i can still stack all of them ?
Pretty sure i read somewhere that you can't take an AVI of Jupiter longer than 90 seconds somewhere
Regards,
Paul Fleifleh