-
24 fps debate
Hi,
This is actually a re-post of a reply i did to another thread, for which I got no response. I really would love to have somebody’s opinion on this topic.
Thanks Eric
Read on
——-
Am I wrong in saying that the “film look” part of the panasonic cameras have nothing to do with 24p?
I’m going to put down a few conclusions I have come to, and I would like to know your thoughts and also know if my perception of the subject is wrong.
Ever since I saw the first shots to come out of a DVX 100 at 24p a few years back, My first thoughts were: “I like this cinegamma feature, but could someone get rid of this awfull strobing!”. I feel the same now when I see 24p HD.
I love working in progressive and I love the “non-ntsc video” gamma but I dont understand what there is to like or that compares to film in the 24p strobing.
Here is my technical interpretation, tell me if I’m wrong.
(This applies to projects being finished for North American TV, I know and understand that 24p is most appropriate for film delivery)
If we do the math, every 24p camera availlable today (exept the Sony 900) have a timebase of 59.94. Therefore when shooting 24p the camera actually captures a frame at an exposure of 1/60th and marks it for playback for the duration of 1/24th. Then the 3:2 pulldown, etc… is then applied for playback on video systems.
On the other hand, a film camera running at 24fps, given the fact that the shutter be at 180, captures a frame at an exposure time of 1/48th and is played back at 1/48th.
Film plays back motion at the same rate that it was captured in realtime, outputing a sequence of contiguous moments in time, blurring motion that was faster than 1/48 of a sec.
The 24p video camera takes a short exposure and plays it back at a slower than it’s realtime capture rate, then, it skips to another “short” frame taken at a non-contiguous moment in time and repeats the process. This gives you choppy movements in your footage that you dont get when playing back 24fps film even on video with 3:2 pulldown.
This is what my eyes see when I look at 24p. And when I look at a still frame from digitized film footage and compare it to a still frame of “film gamma” HD, I love what i see in HD no matter what the recorded frame rate was, so this has nothing to do with 24 or 30 fps playback or record. Also, when you need to time strech your footage, 24p is even choppier that you can’t really go under 70% of real time and still have a watchable motion.
Therefore, I’m in favor of 30p when working exclusively for TV or DVD deliverable projects and I tend to discourage the use of 24p in such cases.
Hence my conclusion is that 24p for video has nothing to do with “film look” and is more of a nuisance than a “special feel”.
I have had countless philosophical debates on these issues, but never with people that actually had the sufficient technical understanding of the subject matter.
Please get back to me on your opinions of my hypothesis.
Thanks
-
7 Replies
-
Yes, you are wrong.
No, the VariCam at 24 fps & 180
-
Legreck,
When shooting at 24p with all but the Sony Cine Alta system, and of course the shutter set to 1/48th (or 180 degrees) like a film camera, the playback on tape is exactly the equivilent (as far as motion) as film shot at 24p and transfered to tape via telecine. If you don’t like the motion, then you wouldn’t like film either! Granted you can shoot film at 30 fps too, either with the shutter on (1/60th) or off (1/30th)and that provides another “look”. Pick your poison!
As far as Cine Gamma, you are correct, this development which can be found in the DVX’s, HVX’s, HDX’s, Varicams and Cine Altas (and others I’m sure) goes quite a long way in making video less video-like and more film like. The ability to extend the dynamic range, holding details in the highlights while at the same time being able to look into the shadows better can’t help but improve the imageing capabiliies of these cameras vis-a-vis shooting film, either 16 or 35mm. Furthermore, the HD imagers having up to essentially a 2K capability in 1920×1080 mode (and the improved HD optics) increases the sharpness at the same time relative to standard definition video.
To me there really is no debate; there are essentially three choices of frame rate, nameyt 24p, 30p (as you suggest) and 60 (either i or p depending on the networks’ preferance). If you are from the camp that would rather shoot film but have chosen HD for other reasons (economy usually) or are replacing film in your workflow for the ability to preview the final look on the set, or for whatever reason, then 24p is the natural choice. If you’re exhibition is intended for computer (i.e. internet) then 30p might be a better choice, or if you prefer a smoother motion, and finally, if you want the ultimate sharp, live video look, then 60fps should be your choice.
Ultimately there is no one “best” speed; we’re very fortunate that the manufacturers have built speed flexibility into the cameras (like the film cameras before them) so that the producer, with consultation with the DP and post production supervisors and client can determine and choose what is best for that particular project or intended exhibition scheme. If nothing else, I’d call this progress!
One other advantage to 24p of course is for conversion to PAL standards, mastering at the speed makes a better conversion motion-wise than the 30 or 60 options. There are times when this is very important, at other times, not at all. Whatever your framerate, also remember that you have shutter control too to “adjust” the look that is determined by the motion.
JS
-
I think one of the major causes of that “strobing” you are referring to from 24p video cameras is due to camera movement. A lot of people want to shoot 24p on these cameras to get the “film look” but then use the camera like they would any other video camera, hand held, fast pans, shakey shots, etc. If you look at 35mm film shot in this style you will also see the “strobing”.
-
Wow- this is like a flashback to 2003. I thought we were all over the whole ’24p isn’t really filmlook’ threads. Thanks for the memories, good times… 🙂
-Noah
Unlock the secrets of the DVX100 and Final Cut Pro!
https://www.callboxlive.com -
I find that people looking to see if there’s strobing in 24p usually find it.
I also find that if I look for it myself in film originated material, I find it.
24p video suffers from the fact that there’s people who will go looking for the fault…not realizing that if they don’t go looking for it, they won’t find it.
New website, new work online:
https://www.nateweaver.net -
I ecently took delivery of my new HDX900. I have shot some tests prior with the various 24/30/60 frame rate settings while deciding on a “look” for an upcoming architecture series. I thought I would visually alter the look between the on-camera interviews and the b-roll (mos). I decided to go with 30 for the interviews and 24 for the cover material.
The client has just taken delivery of the new 1400 deck and we were looking at the rushes in order to agree on the visual approach. I noticed some severe “sflicker” on the horizontal plane which was not what I was expecting. I’ve used 24P with the varicam and never encountered it. I’ve shot 35mm and 16mm and loved the idea of a reasonabled priced alternative that the 900HDX offered. When i saw this test I was confused.
It turns out (after speaking with a Panasonic rep) that until the material is digitized into the non-linear environment this “flicker” while viewing the raw tape off the 1400 is a natural artefact of the dropped frames.
“The flicker that the customer saw was probably the pull down artefacts. When 24pa 2:3:3:2 is removed you should have a 24fps time ” Final Cut has a frame rate converter built in to the software.
Visualeyes
-
One thing about the film look that you may not be considering is the butterfly shutter in every film projector since about 1937 What happens in the theatre is that each frame is actually projected twice. So the actual number of frames you see per second is 48. This of course is done to smooth out the flicker. The old silent films (pre butterfly shutter and lower frame rate) were of course called the flicks! for the obvious reason.
In many years of shooting film for TV especially in 16mm. When we could afford the extra footage we often shot in 3ofps. The results to my eye were better looking. There is nothing magical or beautiful about 24fps it is simply the slowest rate that film could be run with the early sound recording striped on the film.
When we consider the film look I feel it is always important to talk about how the camera is smoothly supported in movement with dollys steadicams and cranes. The look of wheels operating. The careful and often artistic lighting, and the approach to each shot which involves much more time planning blocking lighting and care in composition than is typical of video shooting.
Although not technically accurate about the Varicam I feel the first poster here has a point about the attempt to have Varicam video look like film. The predominant beauty of film has more to do with, the gamma, the dynamic range, the ability to capture subtle shading of both bw and color information and finally the craftsmanship exhibited by the more experienced and larger crews who typically shoot in film. Inasmuch as video cameras move the gamma curve extend the dynamic range and differentiate between shades of bw and color they will be capable of looking more like film. This will work out especially well when the crew/support/and style of shooting are similiar to the long proven methods used to produce movies.
At this point video cameras do not produce the full range of image quality of 35mm film. Certainly they are rapidly getting closer. IN some ways (such as overall resolution) they exceed film. 24P by itself without the other changes which are both already developed and coming in next gen. Electronic Cine. cameras is really just a marketing ploy to move people toward accepting electronic images as some how more film like. Really film is beautiful it is not just a flicker and pull down artifact.
Reply to this Discussion! Login or Sign Up