I keep making the same mistake by uploading iMovie videos with the automated “Upload to YouTube” option. The videos uploaded this way look absolutely horrible. I just did a vacation video with a Canon 5D Mark II and Canon lenses at 24fps with great video quality – but the upload looks worse than my old $300 Casio camera.
So convert the iMovie videos first onto your hard drive then upload through your YouTube account. I mean it’s just a boring vacation video but $4,000 of Canon gear should look better than a $300 Casio right?