When I upload a video onto youtube, the result is a somewhat darker image than if I view the video via any other means (VLC player, windows media player, etc). For instance in this video: http://www.youtube.com/watch?v=MTBI6IJKtnc at the 1:53 mark the dark background should have little white static hairs on it (using the hair FX from Sony Vegas), which appear fine when played locally, but after the youtube upload it's so dark that they're practically invisible. That's not to mention dark scenes in videos that of course look much, much worse than normal. I am outputting the file as an mp4 with Sony Vegas, and even after outputting it it looks fine on my computer, just not after the youtube upload. I have tried viewing on different computers also, and it's always the same.
I ve had the same experience with my Youtube videos. I couldn't figure it out. A first I thought it was a problem with my computer. But now that you mentioned it I see that is maybe a Youtube Thing.
Right, but I've seen plenty of other videos on youtube that don't have the same problem, so are they just oversaturating their videos intentionally knowing that youtube will make them darker, or is there something else at work here?
Well you think they don't have the same problem but you really don't know without seeing the original video they UL'd. Yes - the problem is with youtubes (as with many streaming sites) encoding of the vids. Like others have suggested make a few tests adjusting the saturation or contrast by 10%. Once you find a version that uploads well use those same specs for future UL's.