What are the advantages of 24p?

[Sean Parker]

I've played around a fair amount on a friend's 7D, and tried out doing a 24p vs. 30p comparison. I tried doing the same shots (with a fair amount of motion involved) at varying shutter speeds on both frame rates (for those curious, the shutter speeds I tried were 1/30, 1/50, 1/60 and 1/80, and all had the same concerns). The results had me wondering.

What, exactly, are the benefits of 24p?

I say this because the 24p shots looked... stuttered somewhat, choppy even. It wasn't "bad" but I felt that the 24p framerate was too slow for my eyes. It was as if I could see where each frame began and ended as the footage played back, a problem I've never had with anything 29.97 or higher. I've seen good 24p footage from other cameras (even thought 5D material converted from 30 to 24 looked fine), but something about the 7D's 24p doesn't sit right with me.

Granted, I could have done better tests. The camera was handheld, and a tripod would've allowed me to compare the two in situations that would more closely match the work I do (which is independent narrative film). Still... when I did try using the 7D on a tripod, my brief time with it seemed consistent with my findings, and that any sort of camera movement (like panning) made the stuttering obvious. Not "drop-frame memory buffer"-type stuttering from having too slow of a card, but consistent, disappointing choppiness. And if 24p on the 7D is the kind of thing that you need to have a static camera for to make it work, that would really disappoint me because I really want to try Steadicam and dollying footage on my next project.

It disappoints me because I hear many praises spoken of 24p and its "cine-like" qualities. But after what I've seen, I fear that unless one were planning on laying back the footage to actual film stock, 24p offers little benefit to me. Or so it appears.

I am willing to be enlightened if I am horribly wrong. In one month I will begin filming a feature and want to make sure my thoughts on framerates are sound. If anyone has any advice or thoughts, I would really love to hear it. Thanks!

P.S. - I don't know what this might make some users on here think of my taste in the technical side of things, but I think 30p on the 5D looks good. Really quite nice, I have no issue with it whatsoever. Which is why it concerns me when I hear sweeping dismissive statements from outspoken individuals (on other noteworthy sites) that boil down to "The 5Dmk2 is a nice novelty, but until it gets 24p, its output is completely and utterly useless." I wholeheartedly disagree, but to each their own. Anyways, thanks again for your time.

[Perrone Ford]

Hmmm,

Well 24p doesn't work for everything. Unless you are going to handle the camera like you were shooting film, it's always going to look like crap.

Advantages:

1. It takes up significantly less space than 60i or 30p allowing less compression (and higher quality) in the same space.

2. For internet streaming, the lower bitrate is easier to move along the internet.

3. Obviously easier if you intend to lay back to film

4. Not all external recording devices can sync to 30p.

5. If you need to distribute outside the US, 24p is a LOT easier to do with quality than 30p or 60i.

6. Aesthetic. When shot well, it's a really nice look. But it takes skill and practice. If you are seeing choppiness when you pan, then pan slower. The 24p on these cameras is no different than film 24p. This is why you don't see a lot of panning in Hollywood.

[Sean Parker]

Good points, Perrone. I'd forgotten about the benefits of lower bitrate and ease of conversion for international distribution.

You're definitely right about panning, can't say I've seen it much myself in the industry. Do you think that dollying would have any of the same issues?

I think I'll try some more tests sometime, because I definitely want to get the best sense of what 24p is all about. One more question — when shooting 24p, do shutter speed rates sync up as they would when shooting 30p (i.e., do I still use 1/60 for artificial lights in the U.S.)?

[Mike Peterson]

With dollies the background moves a lot slower than with a pan, add to that the fact that most dollies are very slow and you tend not to have any problems

[Barry Green]

The benefits to 24p, and why it's such a hot topic, are that it emulates the motion signature of 24fps film.

24p is not more accurate at capturing motion than 30p or 60p, it's not as smooth in panning or anything else like that. But it happens to capture motion exactly the same way that movie film does, and that's why it's popular. When used with the same techniques and same care as movies are shot, you can replicate the feel of film-shot footage.

(24p doesn't make your footage automatically look like a big Hollywood film, of course; obviously lighting and art direction and all that other stuff are absolutely unrelated here; we're talking strictly about the motion of 24fps)

[Brian Drysdale]

It has been suggested that film frames have a slightly softer effect due to the mechanical shutter fading each frame in and out compared to the direct action of progressive frames in video.

The American Cinematographer manual does have a table of panning rates, I wouldn't say Hollywood doesn't do pans, more that they're controlled pans. Hollywood can do whip pans as well, just they're motivated camera moves.

[Perrone Ford]

Originally Posted by Brian Drysdale

It has been suggested that film frames have a slightly softer effect due to the mechanical shutter fading each frame in and out compared to the direct action of progressive frames in video.

The American Cinematographer manual does have a table of panning rates, I wouldn't say Hollywood doesn't do pans, more that they're controlled pans. Hollywood can do whip pans as well, just they're motivated camera moves.

Not quite sure how this works....

Shutter opens, shutter close, film gets pulled down, shutter opens, shutter closes. Where is the fade in that mechanical movement?

And yes, Hollywood pans. But the physical movement is generally much slower than what people using 2 pound handycams call panning. And yes, panning to keep a subject in focus is vastly different than unmotivated whip pans. Funny I just watched the Bourne Identity the other night. Frenetic, high motion, and all very, very controlled.

[Brian Drysdale]

I believe the theory goes that the mechanical shutter doesn't instantaneously expose the frame, but there is an extremely quick wipe on either side of the shutter as it moves across the frame. Less a square wave exposure, more a truncated saw exposure action. This is a thought that someone on CML had on the subject, it's only a theory and perhaps would need testing, but an interesting one.

[Brian Luce]

Originally Posted by Perrone Ford

And yes, Hollywood pans. But the physical movement is generally much slower than what people using 2 pound handycams call panning. .

Thank you. Of course Hollywood pans. What you won't see much of is zooming.

[Liam Hall]

The biggest advantage of 24p over other frame rates is simply that it is the frame rate of a cinema projector. So, if you want your $10 micro-budget feature to be in the running for an Oscar you better make sure it's on 24p.

Personally, I prefer the temporal resolution of 24p/25p to that of 50p/60p, but that's just me:)

[David Chapman]

Just to throw this in there, 24fps is less manual frame by frame animating, keying, tracking, per-pixel painting and overall shorter process for visual effects and post compositing. If you have a 6 second shot, the difference from 24fps to 30fps is 36 frames. That's 1 second and a half extra! Some studios are at $300 a frame, if not more. Michael Bay used Digital Domain for a last minute close-up shot of the Alice Pretender that wasn't shot previously. They had a team of 20 people working on less than 70-something frames. 24, 48, 72—that's 3 seconds. Three seconds in the 30p world would have been 90+ frames, depending on the exact cut.

[Sean Parker]

Thanks, everyone, for your input.

I did some further 24p tests today, and was rather impressed by the results. Action didn't strike me nearly as choppy as before — static camera shots were beautiful, and dollying/steadicam-type movement was perfectly acceptable. I did have a few issues with panning not looking quite as good as I'd like, but I was using a bad tripod and a fluid head would probably fix most of the issues.

So consider me a newly-converted 24p supporter. Only issue is that I may be forced to shoot my film in 30p unless Canon miraculously comes out with their 5D 24p update in early January and Tramm manages to make a record-time Magic Lantern update that incorporates it.

[Sean Parker]

I'm going to start up production on a feature in mid-January, and I come seeking advice.

I have access to both a 7D and a 5D2 for the production, and would love to shoot in 24p. Phillip Bloom "reported" that the 5D update would be out in January, and if so, fantastic (by the way, has anyone heard similar reports — or does this seem unlikely?), but then there's the unclear issues of whether or not Magic Lantern will be able to utilize the new firmware, and if so, how long it might take. I don't depend on much from Magic Lantern aside from turning AGC off, so it wouldn't be the end of the world if it weren't doable (I could probably record externally or use some other workaround, heard about some sort of AGC-disabling accessory for the JuicedLink), but it is a nice piece of software and the zebras are nice. Any word on if Canon's update might do something about AGC? Jeez, it would be an easy fix to do...

I could probably do without the 5D for the beginning of the film and stick with the 7D, but I'd really like to shoot with multiple cameras simultaneously and I love being able to get a wider FOV from the full-frame off my lenses.

My question is: Would anyone recommend shooting 24p on the 7D, 30p on the 5D, and then converting the 5D footage into 24p afterward — then, once the 5D update comes out, switch to shooting 24p across the board? Or does that just sound like a bad idea? My other options are to stick with the 7D for a while or just go with 30p — not my preferred choice, but of course the framerate doesn't make the movie. Any advice would be appreciated. Thanks!

(Please feel free to consolidate this post into another thread if it's covering old ground.)

[Marty Welk]

why stop there if its so great, why not go to 18FPS and really wow them, look just like an 8mm film from 1950, cant think of anything that would be more progresivly :-) like film .

i wonder how much of this is not because of looking like film is having a rotten frame rate, but looking like film doesnt COMPRESS the video at 20-1 before it even gets to the NLE?
with less frames the compression isnt as high so it wont all look like Jpeg at 5.

we cant do the contrast capability of film, with video still stuck around 3or4-1 contrast, so becomming film itself reguardless of the chip size or the frame rate, the one great thing that film has , the ability to originally capture huge variations in bright and dark while still rendering the parts of bright and dark, dont exist in video yet.
Film doesnt dump 1/2 the color pixels to wedge it into things , film doesnt even plop its color on top of its luminecence
film doesnt need 3 chips or striped filtrations to re-assemble color, as there is such thing as color film

While it can certannly make "A film" it cant BE film itself (yet) only film is that to date, want to make a film, like film, use Film, want to make a good Film using video, then your using video and why were trying to get worse frame rates makes no sence.

if were supposed to BUY into something that assists us in video to Make a Film, the first thing we need is a vastly expanded contrast ratio.
the second most usefull thing would be a less compressed image
the third would be to add in some noisey grainey trash all over the picture , because that was a FLAW of film.

so while progress might suggest that we have holografic 3d images , that look like reality
ART suggests that a Painting looks better than a photograph, you just have to see in it the art
So in 2050 when everyone is viewing psudo reality 3d holografic images , as recorded on crystal data storages
woody allen is going to configure it back to 2D turn it black and white, put noisey grain in, and cut the frame rate to 24, and make another fabulous woody allan movie :-)

ahh its the Surealism, or realism , that is what is in a film, and that has nothing to do with any of that.

even a film transfered to video the film itself has collection "chips" that are closer to human eye contrast and color capabilities. with video things Blow out, with film you can capture much more, once on the collection media, transferring it from there is easy. that is why a film can be transferred to video just fine, but video cant give you the range of film (yet).

[Mike Calla]

Originally Posted by Sean Parker

My question is: Would anyone recommend shooting 24p on the 7D, 30p on the 5D, and then converting the 5D footage into 24p afterward —

My 2 (and a half) cents - Shoot one or the other!

Shooting on, what is essentially two different frame rates/formats might be fine for short form but for a feature it will just create more headaches than it solves, especially with sync sound!

My 1/2cent
Something else, besides the 24fps that the 7D has over the 5D is DOF. The DOF on the 7D is on par with S35 motion picture cameras. So now you have two things which make the 7D psychologically closer to film than the 5D.

But if you want really beautiful, almost surreal bloomesque images, then maybe the 5D is better.