Out of curiosity, have you tried uploading the video to youtube at 18 fps?

+1

Yes John. If the entire timeline is 18fps, then I can set properties and render to 18fps and upload to YouTube and it looks good to me. Motion looks normal. To see the YouTube frame rate, I downloaded the YouTube file and the frame rate is 17.872.

When I integrate 18fps footage into a larger timeline of mostly 29.97 footage, it looks ok too. . but I'm not sure it couldn't be better. Something to do with the type of pulldown.

... but I'm not sure it couldn't be better. Something to do with the type of pulldown.

It depends on how your resampling is set. See Chienworks' explanation here.

If you're willing to open up the AviSynth can of worms, you could convert the frame rate to 29.97 using MFlowFps (part of MVtools) with a script like this:

AviSource("d:\fs.avi")
ConvertToYV12
super = MSuper()
backward_vec = MAnalyse(super, overlap=2, isb = true, search=3)
forward_vec = MAnalyse(super, overlap=2, isb = false, search=3)
MFlowFps(super,backward_vec, forward_vec, num=30000, den=1001, blend=false, thSCD1=352, thSCD2=110)
AssumeFPS(29.97)

Use Debugmode Frameserver. Render to an AVI intermediate (MagicYUV, Cineform etc.) in VirtualDub.

I have a related, very old tutorial here, which is over-complicated in this case because your source isn't interlaced. However it might help, and I recently added a list at the top of some specific tools I'm using for this type of stuff.

Setting this up can be complicated, but the rewards are nice if you're fussy about quality.

Nick -- I doubt if I'd go all the way in the AviSynth route you suggest .. but I disabled resample and that looks good to me. Thanks!

I wonder how it would be to render to 24 fps from both. Fairly common pullup/pulldown ratios, and the extreme 3:5 ratio from the 18 fps is avoided.

Good suggestion Musicvid. I'm going to try that later today or tomorrow.