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24fps w/ the Kona LH card – question…
I recently shot some footage w/ my HVX-200- set to 480/60i – recording to tape. And my wish was this footage to be recorded in 480/24p . . . And I know from reading Barry Green’s notes, that to convert 60i to 24fps is a “no-no”, because of the “field/frame blending-mishMash.” I tried a couple of ways of converting this footage:
1) Placing the 60i clips in a FCP 24fps timeline and have FCP convert it.
2) Using “Film Effects” plugin from Nattress (nattress.com)to convert the clips to 24fps.
3) Using my Aja Kona LH card to digitize the 60i footage using the 8bit Uncompressed 23.97 setting.
The worst quality was #1, the second best was “Film Effects” but the best results came from the Kona card. The captured footage has a very subtle “film look” at 24fps and I find it even more pleasing than footage shot in 480/24p w/ the HVX.
Now my question is, what exactly is the Kona card “doing” . . . is it looking at the SDI signal as if it were “camera footage” and capturing it in 24fps on the “fly”? . . . or is it doing more stuff digitally: using mathematical calculations, etc. Just curiouis….
Grant Taylor
(for Gary Adcock… Varicamp L.A. July 2006) -
5 Replies
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The Kona card is attempting to remove normal pulldown on the fly. So what’s it’s doing is skipping what it thinks is a pulldown frame and leaving you with 24p. It’s totally not the right way to do it. Step though your footage frame by frame and you’ll see what’s going on. Even though you shot it 480i60, are you sure you didn’t set the camera for 24p in 480? 24p is recoded in a 60i stream. It is then up to you to remove the pulldown (normal or advanced). FCP has ways to do this as does the Kona card.
Jeremy
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[suncloud] “Now my question is, what exactly is the Kona card “doing” . . . is it looking at the SDI signal as if it were “camera footage” and capturing it in 24fps on the “fly”?”
actually it is being dumb and trashing the standard 3:2 pulldowns redundant frames,
bet you Used “CAPTURE NOW” didn’t you.
That is one of the little “undocumented features” that recording Uncompressed direct into the computer without deck control will give you a 23.98 frame rate, it is actually not supposed to work that way, but AJA has not ” fixed” it yet.
By the way it works with 720p 60fps footage also so you can achieve non slo- mo @ 24p
but that only works over HDSDI.
Thanks Grant.
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsMy DVD’s are available @
https://www.rastervector.com/dvd/dvd.html -
[JeremyG] “It’s totally not the right way to do it.”
and Jeremy is totally correct it is not the correct way to do this type of conversion.
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsMy DVD’s are available @
https://www.rastervector.com/dvd/dvd.html -
Thanks for the replies. Yes, I DID do a “Capture Now” . . . so Gary, are you saying that the Kona card is NOT doing the 3:2 pulldown? . . . so it’s just capturing 23.98 fps on the “fly”, . . . just capturing random frames on it’s “own” (sort of speak)? If so, I know it’s not the “way” to do a 3:2 pulldown, but it sure has a nice pleasing affect. Interesting . . . !
Thanks,
G.
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[suncloud] “so Gary, are you saying that the Kona card is NOT doing the 3:2 pulldown? . . . so it’s just capturing 23.98 fps on the “fly””
Grant
It is my understanding that because you are asking it to remove the Standard 3:2 pulldown, which in the SD world of the offline process did not originally have any flags to determine cadence. So the NLE’s were designed to just remove the 1,3,4 frames based on a 0-5 frames as counted in 24fps.
The board is assuming that you are sending it 24 frame material you told it that and you are sending out ANALOG video from the HVX, so it is not looking for flags it is just capturing the 24 frames a second – dynamically reverse telecining your material whether it is supposed to or not.
by the way Pulldown is traditionally thought to be the addition of frames.
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsMy DVD’s are available @
https://www.rastervector.com/dvd/dvd.html
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