"QUESTION:


It depends. Sites such as Vimeo only support 24p unless you pay for the full service and then you can get support for 25p. What ever frame rate conversion they use I doubt it'll be done with as much care as you would take. I've seen a fair amount of juddery pans on Vimeo.

If it's for download or streamed of your own servers then it will not matter except 30p can need more bandwidth than 24p.

"...or if you want to achieve some kind of effect right?

I'm not certain that converting 30p to 24p makes it look quite the same as something shot at 24p. I've converted 50p to 50i and the outcome feels different to shooting 50i, probably because of the 1/100th shutter speed.

Bob.

Bob's expanded answer is absolutely correct. Also, converting 30p to 24p or 25p is extremely difficult to do correctly.

OK, good thanks! :)

Reg 30 to 25. Even though this IS difficult, it is very depending on what content there is. Architecture / interior / slow moving yachts etc which I just converted to 25 worked very well. Had it been a game of tennis or car race etc things would have been different of course.

Lars

isn't 29.97 only for interlaced anyway? I've used lots of CG I've rendered @ 30fps & just made sure vegas imported it as progressive in a 29.97 project. Some has ocationatly been rendered to 29.97, some has been rendered to 30 (if i'm thinking, but it's all been under 5 minutes if that matters). Some is on youtube, some is on my website, some in SD, some in HD, some in 1/2 SD. I've never had ANYONE complain at all about stuttering, judders, etc. 29.97 is drop frame, just for timing, so it doesn't really have less frames in a video that's 30fps, just adjusts the length of each frame.

But if you CAN render to 30fps for delivery, do that. Since it's the same as the original, less possible issues that way. :) Computers don't really care though.... I've tested out 2.5fps to 120fps, always plays back smooth on my comp.

Computers don't care.
Only issue I've noticed is if the display's refresh rate doesn't match the frame rate sometimes you get problems with 'torn' frames.

However it does matter if you have mixed frame rates on the one timeline as they're all going to get rendered to the one frame rate and then you could have problems. Vegas does a very good job of converting 50i<>60i, almost as good as quite expensive hardware boxes. The problem is 25p<>30p.

29.97p<>30.00p is such a small difference that it can be accomodated with a simple speed change done one of several ways using Vegas, audio should be easily handled for that as well.
24p<>25p is the same although you can get audio problems such as the one Megabit had.
The problem that can arise if you ignore the problem seems to be that Vegas may simply drop a frame. It only happens quite rarely going 29.97p<>30p and even then it seems you may never notice it.

My policy is to try to get things right as it isn't that hard. Then if something wierd does happen it's one less thing to consider as the source of an issue.

Bob.