16mm Footage Rough and Jumpy…

[Steven Gonzales]

Did you convert this footage from video rate (29.97) to film rate (24 or 23.98 frames per second)? If so, the footage can get “jumpy” if the sequencing of the reverse telecine is not correct.

[Please_do_not_use_all_caps_for_your_name_or_when_posting]

thats what I thought too… but the raw footage before I bring it into the timeline is 24fps and still it is jerky and actually looks interlaced which seems odd to me since it is a capture from 16mm. I didn’t do the capture from the digibeta to vid myself so is there a chance something could have been done wrong in that capture?

[Steven Gonzales]

Digibeta is a 29.97 format, so somewhere along the line it was converted, and perhaps incorrectly. It was either converted via software (reverse telecine) or hardware. You should find out the history of the clips to find out what went wrong.

[Please_do_not_use_all_caps_for_your_name_or_when_posting]

I know that it was transfered at a reliable commercial house from reel to 16mm then someone with access to a digibeta deck did the transfer from the tape to an external drive which I now have. The clips show up as 24p and to me they look odd, camera movements are very jumpy looking and there is a good deal of what i think looks like interlacing issues. Im wondering if I go back to a commercial transfer house and just pay for a transfer from the original tape back to my hardrive if it will look better. 16mm should not look interlaced correct?

[Steven Gonzales]

Interlaced isn’t the problem. What happens during film to video transfer is that the transfer is done by fields in a 3-2 or 2-3 basis.

So the first film frame (A) (using 2-3) creates 2 fields, or one complete video frame we’ll call 1. The next film frame (B) creates 3 field, which is complete video frame 2 and 1/2 of video frame 3. Then another two fields are created from film frame (C), which is the 2nd half of video frame 3 and the first half of video frame 4. Then 3 fields are created from film frame (D), the 2nd half of video frame 4 and both fields, the complete frame, of video frame 5.

So the 5 video frames are composed like this:

AA BB BC CD DD

So video frames 3 and 4 share frames from different film frames.

When you try to go back to 24 frame video, you need to extract properly. If you start extracting assuming 2-3 sequence at video frame 1, you get the correct 4 video frames for 24 fps playback:

AA BB skip a field CC DD skip a field. Four video frames with the correct information.

however, if you start the same extraction on the second frame, you get

BB BC skip a field DD DA skip a field. Four video frames, 2 of which have information from two different film frames (perhaps what you see as “interlace”.)

If the method extracts only the first field, and starts on the 2nd frame, then even worse things can happen:

AA BB BC CD DD

B skip field B skip field skip field D skip field D skip field skip field

You end up with no A frame and no C frame at all.

This is a simplification, but you can see a lot can go wrong.

[Please_do_not_use_all_caps_for_your_name_or_when_posting]

yeah seems pretty complicated. Do you have any suggestions in terms of trying to go about fixing the issue. I cannot really find out the settings used to pull the quicktime from the digibeta tape. Im basically just looking for a clean image and the current one is pretty jerky and the image even seems a bit muddy. I guess I’ll just pay the commercial house for a clean transfer and hope that solves it

[Steven Gonzales]

I don’t think you need another transfer. I think you need to get the original files on disk (from the digibeta at 29.97, before converstion) or recapture the digibeta and convert it to 24 again.

[Please_do_not_use_all_caps_for_your_name_or_when_posting]

So the best thing to do is to re-capture the footage from the digibeta onto the hardrive? I tried reversing the telecine in cinema tools but I get an error when I try. it says that the footage is not in NTSC format.

[Steven Gonzales]

Either that or find the files from the original capture, before they were changed to 24.

[Please_do_not_use_all_caps_for_your_name_or_when_posting]

great thanks,
I think I will just pay for a professional transfer from the digibeta to make sure that everything is optimal…