I need help understanding digital video resolution sizes

[JTDennis]

I don't have much experience with digital video. I need some help understanding resolution sizes. I'm trying to put together some video podcast training videos (not on digital video thank goodness). I'm using Snapz Pro X to for my screen captures. The only software I have to edit the video is iMovie and Quicktime Pro. My question has to do with the video dimentions. What is the best size to capture the video at (720x480, 640x480)? The real problem for me begins in iMovie when I import the .mov files. It seems to have a mind of it's own and unless I've captured the video at 720x480 my video is distorted. I guess I could settle and capture all my screen captures at this size, but for me it's a little long width wise for a video podcast. I've noticed that most video podcasts are pretty square or around 640x480.

Could anyone help me understand video dimensions a little better.

Thanks!

[The Repro Kid]

What video format are you choosing when you create your initial project? I would think MPEG-4 would be the logical choice and the most likely to accept your 640x480 captures without stretching them. Just a guess. I don't use iMovie.

Second thought, have you tried doing the work in the distorted manner it is displayed and then manually setting the correct size when exporting the movie. It's a bit buried but it's there:

Go to File menu Share... then select "Expert Settings" in the "Compress movie for" pop-up then hit the Share (enter) button wait a bit and then select "Movie to MPEG-4" in the "Export" pop-up and choose the Options... button then select "640x480 VGA" in the "Image Size" pop-up. This could also work.

Even if you choose MPEG-4 as your initial set up and your capture was not distorted, I would still think you'd have to go through the expert settings procedure and select the MPEG-4 and the proper export size. This is also where you'll be able to control your compression and streaming settings, all of which will be necessary if this is intended for a blog.