As stated above,when you select "render as" thats just the beginning. Which template are you using?. Dont use the default.You must choose PAL or NTSC?, Widescreen or 4x3? Then click on 'custom' and select your render quality. Then click on the 'video' tab at the bottom and select your field order and video format. Remember you can always select a short piece of your timeline and select 'render loop region only' to do a short render test to see how its gonna look. Hope this helps.