Help with Rendering..

[wizekraker]

Ideally how big does 30min video should be?

That depends on what you mean by "ideally". If you mean best quality, you could get up to 2GB/min, if you mean lowest filesize, you can go as low as you can get; for a decent middleground, my rendered videos would be around 700MB for 30 mins.

And are those vides better quality than the video I posted? because I think my size roughly the same too

[KoffeinFlummi]

You see for yourself (those are the only battlefield videos i have that are not full rounds):
http://www.youtube.com/watch?v=TaO9_UL05EY&hd=1
http://www.youtube.com/watch?v=02YpIVXSlXM&hd=1

They're not super-high quality, but i think it's better than the video you showed.

[Hgx]

Ideally how big does 30min video should be?

That depends on what you mean by "ideally". If you mean best quality, you could get up to 2GB/min, if you mean lowest filesize, you can go as low as you can get; for a decent middleground, my rendered videos would be around 700MB for 30 mins.

And are those vides better quality than the video I posted? because I think my size roughly the same too

Usually for my case, a 30 min video, recorded full size in Fraps, compressed and then rendered in 720p at 60fps is 1,80gbs.
In 90fps that would be.... 2.20gbs maybe.

Quality example here:

Full Size - 60fps - 720p - 25 mins - 1,7gbs
http://www.youtube.com/watch?v=h-CUNlZdGtE