Variable Frame Rate question- opinions? facts?

[roro20]

Looking for your opinions, or better yet for anyone who has done a comparison... My project will be alot of fast moving action. Probably half of the footage for the project will need to be slowed down (either in post or in cam). The other half of the footage will be "real time". Not all of the "slowed down" footage will be slowed down to 50%- some will be 70-80%.

My question is... If I shoot in 720P 30PN and Acquire at a 60 Frame Rate (in camera 50% slow mo) would 720P 60P acquired at 60 Frames and slowed down to 50% in post give me the same quality.

Same question the other way... Would 720P 60P at 60 Frames give me better resolution at 100% speed than "speeding up" the 30PN/60Fr footage to 200%Since at least half the footage will be either slowed down (or sped up, if I end up going 720/30PN @ 60 Fr), I am just looking to see what is going to give me the best looking footage overall.

I have done my own tests- I just want to see what everyone else thinks to see if my thinking is along the same lines.

Opinions? Hope this wasnt TOO confusing. Thanks.

 

[Barry_Green]

1. Depends on what you mean by "slow down in post"; if you're talking about having the computer synthesize frames or something, you wouldn't do it that way. You wouldn't "slow down in post", per se, you'd just reconform the frame rate. And yes, the results will be 100% identical.

2. 60 fps is 60 fps. As long as you're playing it frame for frame, it's going to be identical in both cases.

 

[roro20]

Reconform the frame rate? I guess I am not quite sure what you mean by that. Typically when I wanted say a 75% slow mo in post I just do a 75% time remap in After Effects. How do I reconform the frame rate as you suggest? I use PPRO CS3 and AE CS3 if that helps at all.

Thanks for your help, Barry.

 

[Coldpizza]

Reconform the frame rate? I guess I am not quite sure what you mean by that. Typically when I wanted say a 75% slow mo in post I just do a 75% time remap in After Effects. How do I reconform the frame rate as you suggest? I use PPRO CS3 and AE CS3 if that helps at all.

Thanks for your help, Barry.

For best VFR I shoot PN on the sweet spot FR. I cut on FCP and normally the clips are acquired to a 25FP (PAL zone) time line and play back in there intended speed. FCP puts none PN clips through a Frame Rate converter I think that is what Barry means by reconform. To my understanding the camera always shoots 50 or 60 fields 720 or 1080 except PN. If a VFR is selected the camera will tag certain frames of the recored ones. These tagged frames later on when passed through the frame rate converter will be displayed while the others are not. PN records only the tagged ones so no Frame Rate Converter needed. As a rule of thumb the less software and process to pass your footage through the better. On the basis of this I recon for best result with the least hassle shoot PN to the FR you want for each scene.