24fps vs 29fps

Hi guys,
I'm in a bit of a dilemma here. Some of the footage I purchased is in 24 fps and some of it is in 29 fps and I have to combine all the clips. So, either I convert the 24 to 29 or vice versa. Which would be the best route to take here and would not destroy the video quality. Btw, I will be using Twixtor for the conversion.

I feel it is always better to convert downwards; 29 to 24. 24 to 29 has never worked for me. It looks jerky.

It's much more effective in software to make frames than throw them away so 24 to 29 is better.

You can, if the footage is appropriate, slow the footage slightly by going from 30 to 24, no frames will go missing and it might be fine or even better. Just do an interpret footage on the 30 fps to read frame for frame on 24 fps timeline.

Great idea Zanyzeus, maybe that would work. Does the quality of video drop if I use a plugin like twistor for conversion?

I don't know twister. But the quality should be just fine if you whatever you use, interprets it frame for frame. I know in Premiere it's just a matter of using the Interpret Footage menu.

If you happen to be using Sony Vegas, you can edit all the clips on the same timeline which is great, BUT! you MUST remember to right click clip properties (or access "switches") and select "Disable Resample" or you will get a strobing. It's a really stupid issue. Must be done anytime the clip is being rendered at a different frame rate than it was shot at, or if the clip frame rate does not match that of the Project Properties.

Thanks Mizamook, but I'm using Adobe After Effects.

Guys, thanks for the help so far! I forgot to mention, but I also have to apply the slow-mo effect to the Video and I've heard that 29 fps can handle it better. So, in that given case would converting the 25 fps footage to 29 fps result in a better slow-mo effect and video?

No, not really - "true" slow motion is that footage shot at higher frame rate than it is played back. Even if you "convert" 24, 25, etc to 29, you are not adding frame data, and the software must interpolate to create the new in-between frames. After Effects does this pretty well, up to a point. That point is of course up to you as an artist, but in your test renders you'll start to notice, which is likely where you'll have to chill out a bit. While it works to slightly slow down footage, and yes, it has been used a bunch, to good effect, in mainstream work, it is better to always go from higher frame rate to lower whenever possible. Now this is where Twixtor comes in. I haven't used it myself, but this is a program specifically designed to fill in the blanks, so to speak, and there are some very good examples of how well it can work. However, it does not work without artifact on all material - it depends on the type of motion in the clip, and whether the camera is moving, how detailed the clip is, etc. It's not a simple program.

I'm very curious to see what you are working on. Keep us posted!