does anyone know why after i import video to my computer, it looks so grainy and horrible.
A) camera
B) computer
C) monitor
D) cable/transfer method
E) video settings
The problem could possibly be due to shooting interlaced video.
Here’s a description of interlacing from Wikipedia. Read up there and especially the external links in the Wikipedia article. 100FPS is a great link that has pictures of what interlaced video looks like when displayed on a computer (ignore the technical stuff there cause he makes it more complicated than it needs to be).
Regular TV is interlaced. Computers (and progressive HDTV modes) are progressive. Interlaced video looks terrible on a progressive display.
You can run your video through a de-interlacing filter. That will remove the interlacing but leaves artifacts. If your source video is 640x480 or above you can remove the interlacing by running the video through a filter that reduces the resolution by half (shrink the 640x480 video to 320x240). It’s quick and dirty but gives good results, certainly good enough for YouTube that will get shrunk down anyways.
If you’re shooting video that is destined for the computer and not your TV then check to see if your camera will shoot in progressive scan mode. That will eliminate all interlacing at the source. Your video on the computer will look great. You’ll be a video star.