Bitrates!?

[sonofisis]

Okay, i'm fairly familiar with bitrates, and I have a simple question.. Okay, i use NeroVision Express 3 to make dvd's, and whenever i put in a movie that's over 2hours, it gives me the option to lower the quality so that it may fit onto a 4.7 GB disc.. well, obviously the bitrate must be a lot more than 3382, seeing that in Standard, most of the my dvdrip movies are maybe 6 - 8 GB.. I noticed that you can customize what bitrate you'd like, which leads to my question.. Say Nero automatically shrunk my 2 hour long dvd to 3.2 GB with a 3382 kb/s bitrate. that means, if i customize to like 4500 kb/s, the file would be slightly larger, utilizing the space it had free.. well, i wanted to know, is it nessicary to adjust the bitrate manually to gain quality, or will the difference in quality not be noticalbe, since a bitrate of 4500 kb/s isn't too far off from 3382 kb/s?
Should I just let Nero do it's thing? honestly, i'm happy with the quality of a 2 hour movie after Nero shrinks it, it still retains maybe 80% of the quality and is still appealing on my bedroom TV, i was jus wondering would a tiny bit more make a diff in quality, is it worth it, to adjust it manually everytime, or are people like me, and content with the automatic process?

[Raga]

You can't possibly adjust it to anything higher than would fit on the disc - that is, if you want to fit the whole thing on one disc?

Exactly two hours gives you an average bitrate of about 4800kbps excluding audio. You can put approximately 170 minutes of 3382kbps quality video on a DVD.

Obviously it's a good idea to use as high a bitrate as possible, every bit contributes to a better picture. I wouldn't care for a hundred one way or another, but if we're talking several hundreds and we're in the 4000 range, it's definitely worth the trouble.

[thecoalman]

If your using full resolutio i.e. 720x480 the video quality decreases quite a bit once you go below 4000kbps. This will be particularly visible during high motion scenes. At the very least I would suggest you use that if the template is using 720x480. That or decrease the resolution.

There's a calculator here for figuring out the approximate max bitrate : https://www.videohelp.com/calc.htm

[sonofisis]

Ok, that makes a whole lot of sense guys.. you're confirming what i had thought in advance, so i held off on burning anything else until i got a response from someone.. the calculator is very useful too, i'm gonna aim above 4000 kbps, thanx.