24P question

[Mick Haensler]

OOOOOOHHHHHHHH…..my head hurts now

[Paul Thurston]

When you telecine/transfer a 35mm film to video and the result is for NTSC frame rate, it gets transfered at 23.976 fps (23.98 fps).

It also is captured as RGB 4:4:4 and not Y, R-Y, B-Y (YUV) 4:2:2.

The difference between 4:4:4 and 4:2:2 makes a difference for motion representation and color. This difference in capture color space is what many point out as a strange difference between telecined 23.98fps and camcorder captured 23.98fps video.

What randy Strome saw, has been noticed since 2000. In fact, I read that the first person in SONY America to point it out publicly was fired. Not that it was a secret, by any means, but it was an issue that only engineers could point out and that most if not all viewers (non engineers) wouldn’t notice or care about.

NOW…

An interlaced HD video transfered to film and the result seen on a movie theater demonstrates the opposite. It looked like interlace HD video (movement and color space.) It did not look like film captured images.

On the other hand…

I have seen the last Star Wars episodes on film and on TV. They both look like film-captured images. The difference is that the HD data was in fact 4:4:4 captured and never went to 4:2:2 color space until broadcast masters where made.

You would probably not guess that color space could affect the representation of movement, but it does.

Now you can understand why the Sony F-23 4:4:4 camera head is so expensive (RGB 4:4:4 capture, F-11 at 2000 Lux, 98% reflectance.)

Please note that regular HD cameras and for that matter SD cameras that capture at 23.98 also portray movement correctly as film captured images would. The limitation here again is the difference between native all the way 4:4:4 color and native 4:2:2 color. You could say that interlace stuff definitely does not look at all times like film, when shot at 24fps/23.98fps, but the same is true of all 4:2:2 video (in the eye of a video engineer.)

Does this mean that 4:2:2 images captured with an HD camcorder should not be used for filmout or TV? The answer is: they should be used. Since the only people who will ever notice the difference between motion portrayal in 4:4:4 and 4:2:2 color space will probably only be… a video engineer.

-Paul

[Ron Shook]

Paul,

[Paul Thurston] “Does this mean that 4:2:2 images captured with an HD camcorder should not be used for filmout or TV? The answer is: they should be used. Since the only people who will ever notice the difference between motion portrayal in 4:4:4 and 4:2:2 color space will probably only be… a video engineer.”

This has been a superb thread and your explanation puts the capper on it. Thanks!!

Because of the entire thread discussion, I think that I now have an understanding of why I, like Craig and others have expressed, tend to feel that 30p looks in some ways more filmlike than 24p when run through a complete YUV, 4:2:2 production/post-production chain. Or maybe it doesn’t look more filmlike, because there are other things going on, of course, but it looks better to me, if it is destined to be video all the way. As John points out 24p in the film projection theater, whether coming from film or video, benefits from multi-blade projection which tames the judder/flicker of 24p.

And it tames the judder/flicker without resorting to artificial cadence pull-down. For video that won’t ever be optically projected, 30p tames the judder/flicker pretty good, again without pull-down.

Of course what I’m talkin’ about applies to NTSC. How Mark deals with the flicker of 25p PAL, I dunno? I suspect that a considerably higher percentage of folks can see flicker at 25p than at 30p.

Thanks to all,

Ron Shook

[Randy Strome]

Hi Paul,

More excellent info!

You wrote:
“The difference between 4:4:4 and 4:2:2 makes a difference for motion representation and color. This difference in capture color space is what many point out as a strange difference between telecined 23.98fps and camcorder captured 23.98fps video.”

I can certainly see how capture color space could impact the “film look”, but am still unclear how it would impact motion representation. Could you clarify?

Best,
Randy

[John Sharaf]

Paul,

The capture of the telecine is dependent on what recording format you use. It is inaccurate and misleading to say that “It is also captured at RGB 4:4:4 and not…”

I fail to be convinced that color space affects the temporal quality of the 24p film look. What if it was in B&W? The motion would be the same!

JS

[Mick Haensler]

So to sum it up…. If shooting for video, shoot 30. If shooting for a filmout, shoot 24. If you shot 24 for film but need to show it on television or DVD, apply 3:2 pulldown.

OTOH…. If you really think 24 looks better and are shooting for video, go ahead and shoot 24 and add pulldown in post.

Did I get it??

Mick Haensler
Higher Ground Media

[Ron Shook]

Mike,

[Mick Haensler] “So to sum it up…. If shooting for video, shoot 30. If shooting for a filmout, shoot 24.”

That’s how I grok it. Of course, if the temporal resolution is more important than the spatial resolution, such as with dance and sports, shoot 1080-60i or 720-60p. The EX does it all.

[Mick Haensler] “OTOH…. If you really think 24 looks better and are shooting for video, go ahead and shoot 24 and add pulldown in post.”

Yeah, but you don’t see pulldown in the optical projection theatre. It’s an artificial adaptation to NTSC electronic display and I believe does effect spatial resolution to some degree, which is why I prefer 30p production for electronic display. The other side of the coin is that we’ve gotten used to seeing movies on TV with pulldown, so we accept some degradation due to the pulldown that we wouldn’t see in the optical projection theatre.

So to each his own.

[Mick Haensler] “Did I get it??”

Ya gots it for me, but perhaps not for you or the next person. (g)

Ron Shook

Ron Shook
Shoulder-High Eye Productions
CreativeCOW Forum Host for Discreet edit*

[John Sharaf]

Mick,

Not so fast!

If you want it to look like film (on TV like displays) shoot 24p. The 3:2 pulldown will be added so it doesn’t flicker. Same speed if you intend to film out (unless your in a 50Hz country where projectors run at 25 fps, then use that rate).

For video, you can still shoot 24p (again if you want it to look like film with pulldown), or shoot 30p for smooth motion and some-what film look (progressive) or shoot 60 for live look.

It’s really great to have all these choices, you just must consider what your final product will be, how it will be seen and educate your clients about the various advantages and pitfalls.

JS

[David Burch]

I agree with the OP, and I’m not convinced the 4:4:4 colorspace is to blame. I don’t accept the projector explanation either. When comparing a DVD movie on a progressive screen to video shot 24p (either 720 or 1080) with the EX1, to me there is a huge difference in motion stutter and flicker. This has nothing to do with pulldown or projectors, as both sources are being displayed in native 24p. For some reason, the film source appears to have smooth motion, even in 24p, while the EX1 footage simply looks jittery. I’m glad I’m not the only one to notice this. I would like to figure this out because there are many advantages to 24p in regards to making a DVD, but so far the results I have seen simply don’t cut it.