If I have an image of 720 x 480 (NTSC) and would like to make it widescreen with the format 4:3 (not 16:9!). How large do I need to crop (inserting the black bars) at the top and bottom? Also, do I need to add right and left black border? here's what i want - type 01: here's what i want - type 02 (this one has blackborder in both L&R side): Just want to know the professional size of it... ty

It depends how widescreen you want it. For a 480-line (NTSC) 4x3 video, to make it 16x9, you need to make 60 pixels at the top and bottom black (leaving 360 pixels of the original picture in the middle). You can make 8 pixels left and right black too if you want, but there's no need. Hope this helps. Cheers, David.

This might help you as well: Aspect ratio calculation tool: