Canon's 24f Pulldown Issue

T

Tom Films

Active member
Can someone explain further the problem Canon has (specifically when editing with Premiere) with 24f footage? This is a quote from Jade's post in this thread

[In Reference to A1 footage shot in 24f HD and downconverted in the camera]

It automatically uses a 2:3 pulldown to embed in a 60i stream. Unfortunately you will not be able to remove those frames in your NLE (Premiere for sure) because Canon forgot to put pulldown flags on those frames. They'll have to be manually remove by other software. I seldom downconvert from 24F because of this issue.
Click to expand...

Can someone elaborate on this issue, what exactly it causes and the best possible fixes or work arounds?
 
When the A1 shoots in SD mode, it records exactly like any other 24p camera. That is to say the 24 frames are embedded into a 60i stream by adding pulldown frame. Normally these frame are flagged so that your NLE know to remove them, and this is indeed the case when the A1 shoots in native SD mode.

Now, when it shoots in 24F HDV mode, there is no pulldown frame added and the raw footage is captured as 23.976 fps. When you downconvert in camera, the A1 once again adds pulldown frames, in a 2:3 pattern to make it a 60i stream, and the footage is captured as 29.97 fps. For some reason these extra frames aren't "flagged" so your NLE won't know to remove them, and you still end up with 29.97 fps footage when imported. This means that while the 24 fps cadence is still there, you may noticed interlacing in the footage. As far as I know, the only way to work around it is to manually remove the pulldown frames by using After Effects to "guess" the pulldown pattern, then export out as 23.976 footage.
 
So is downconverted 24f footage, unusable? Is the interlacing very noticable?

And is this a Canon problem or a Premiere problem?

My plan was to shoot 1080 24f footage and downconvert to SD and edit in Premiere. Sounds like this may compromise my entire plan.

What are other people doing? Surely shooting 24f HD and downconverting is a widely used practice. I can't imagine it would not result in usable footage.

Are there any third party programs that would help with this?
 
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