The Sony XDCAM look vs. Panasonic Look vs. Canon Look ( or Frame Judder in 24p )

[Tyson Persall]

FRAME JUDDER in 24p. I hate it.
On the Canon XL2 its really awful during pan shots. It's obvious noticeable judder. However on the DVX100 I find it pleasing. Motion is much cleaner durning pans. It might have SOME frame judder but its not NOTICEABLE frame judder. I like the panasonic look. IN my experience with the DVX and XL2 (i own both) the DVX is much better for pans. The XL2 better Still shots.

Thus, I wonder how Sony XDCAM handles frame judder. I see judder in feature films and it really bothers me so I guess this is a personal taste issue mostly. -But I want to be able to see clearly during a pan. Not stop start stop start. I know, shoot 30p during a pan right>? But why should i when the DVX renders motion perfectly the way i like it. So this is my top concern. Frame judder. I want a camera that can handle moving shots well and still have true 1920x1080 resolution.

Perhaps some owners of other XDCAMs can tell me how frame judder looks on Sony XDCAMs. (Asumeing the EX will be similar).



* Note: I was going to get the Sony V1U when it came out but heard that frame judder is noticeable. Frame Judder on the HVX is probably like the DVX - but If the HVX had the true 1080p resolution of the EX then i would get it hands down. As we know its really only a 720p cam at best. (with all the upresssing and all)

[Vince Gaffney]

Are you referring to strobing? I'm not familiar with judder. Perhaps a description would help me.

vince

[Eric Pascarelli]

I can't think of what would cause "frame judder" in one camera over another, if frame rate, lens, shutter angle, pan speed and subject were the same (I am sure that rolling vs. non-rolling shutter is also a big factor, and of course interlaced vs. progressive).

What phenomenon causes the appearance of judder, other than the above? I have noticed the phenomenon myself but have never attributed to a particular camera - just the other factors. I have certainly seen it in 35mm film as well. I would be curious to know if there is something I haven't considered.

There have been long standing guidelines about pan speeds in cinematographer manuals to prevent strobing. One basic rule is to watch out for narrow, contrasty verticals in your subject (or horzontals if you are tilting). Large gaps in position frame-to-frame will cause the background to appear flickery.

One of the nice things about progressive video over film is the "360° shutter" which is achieved by turning the shutter off. I hope it becomes the norm to shoot progressive video this way as it makes all motion much smoother and in my opinion more natural (although to most of our film trained eyes it appears too motion blurry). This would be the first thing I would do to reduce judder.

The 180° shutter (1/48 sec at 24fps) that we normally use is based on a "film look" standard and is not necessary anymore, except for its particular aesthetic, now that we don't need that dark interval to drag film through a gate.

[Vince Gaffney]

Originally Posted by Eric Pascarelli

now that we don't need that dark interval to drag film through a gate.

So much for the mystique of film...

[Ron Evans]

Judder is what happens when one tries to emulate the technology of the last century instead of using the full capabilities of todays technologies. The judder is caused by insufficient frames of information for the speed of camera movement. 24 fps was a technological and economic compromise for film( not complete, but the slowest it could be for audio frequency response and film stock use). It isn't necessary today. Using the camera composition, movement and lighting for dramatic effect has nothing to do with frame rate( unless you like your image juddering all over the screen) These effects were used to mask the inadequacy of the frame rate of film. Mostly fixed shots, limited pan, almost no zoom, shallow depth of field to make the juddering motion in the background disappear etc.. There was a reason when transferring to film for distribution but I am not sure how much longer this will last. I disliked the image my film cameras in the early 60's produced( 8mm, Super8 and 16mm)
I am dismayed about the trendy attitude to 24p that prevails on TV to the point that I don't watch much anymore. The combination of 24p and poor MPEG encoding for distribution on cable produces a really poor picture. As I have said before its a bit like buying an expensive modern car and having it modified to ride like a Model T Ford !!!!
Modern technology can remove judder using higher progressive frames rates, 720P60 for example and hopefully 1080P60 too
Ron Evans

[Mark Kenfield]

As I understand it, the "judder" is just a result of panning quicker than 24fps can handle smoothly. Shooting with a higher frame rate is the simplest solution.

[Ethan Cooper]

I personally prefer the more organic "feel" of the Panasonic's 24p (HVX, Varicam) image over the more technically precise "look" of the Sony's 60i (V1u, F900). Although the Panasonics are "resolution challenged" when compared to the Sonys, there's just something about the way they capture motion and color that's pleasing to my eye.

Not trying to start a measurbating war here. Just giving one man's opinion of the cameras that he's used and stating that I prefer the 24p look in most everything but news.

[Thomas Smet]

sharpness and edge detail play a lot into this.

The crisper an edge is in motion the more it will strobe. That is because the sharp edge shows up more and as it moves it changes position very quickly. A smoother edge with more of a gradation into the background will not strobe as much and will look more natural.

The amount of electronic sharpness will hurt this. An electronic sharpened edge is very sharp and high contrast. In nature and in film edges are not like this so it tends to look a little bit more fake when moving at 24p.

On the EX1 I think if we turn off or at least set very low the sharpness this should help. I know it kind of kills the point of having so much detail but that is the tradeoff. Do you want crisp stroby 24p or smooth natural 24p.

[Eric Pascarelli]

Ron,

I completely agree.

We strive for a film look not because it is intrinsically better, but because its flaws are familiar, and are associated in an almost Pavlovian way with the high quality productions we see on television.

99% of the commercials I work on are shot on film at 24fps and 3-2 pulldown added in telecine. This horrible workaround known as 3-2 pulldown is now considered a shortcut to a cinematic look, because when we see big Hollywood movies extruded through our tiny televisions, that's what we see.

We could capture 2.5 times more information, shooting film at 60fps and transferring each frame to a field of video, or a progressive frame, but this is frowned on because it "looks like video" and hence is perceived as lower quality, even though it is obviously much higher fidelity.

Strange but true.

[Craig Seeman]

This will all change over time IMHO. There will be more younger people used to working in video and it's advantages over film.

There's will be a time when we shoot at 60p 4K with chips that will equal or exceed the shallow DOF of film (as needed).

Red is a good indication of that.

Even the EX1 is nearly 2K and can shoot 1080p30 with "cine gamma" controls.

We'll retain the "good" part of film and dump the bad motion and "noise" which people love to call "grain."

Originally Posted by Eric Pascarelli

Ron,

I completely agree.

We strive for a film look not because it is intrinsically better, but because its flaws are familiar, and are associated in an almost Pavlovian way with the high quality productions we see on television.

99% of the commercials I work on are shot on film at 24fps and 3-2 pulldown added in telecine. This horrible workaround known as 3-2 pulldown is now considered a shortcut to a cinematic look, because when we see big Hollywood movies extruded through our tiny televisions, that's what we see.

We could capture 2.5 times more information, shooting film at 60fps and transferring each frame to a field of video, or a progressive frame, but this is frowned on because it "looks like video" and hence is perceived as lower quality, even though it is obviously much higher fidelity.

Strange but true.

[Christopher Barry]

24p is just enough images to make fluid motion, somewhat different to how we perceive images, in the 50 to 60 fps range. The lowered frame rate of 24p creates a more dream like or fantasy environment, part which films often are, fantasy and escapism. Indeed, the future may just move towards hyper real as the standard and desired for all media. I like 24p/25p images for movie content.

[Tom Vaughan]

Great answers. To add to the discussion...

Technically this isn't "judder" (at least as far as I have heard the term used). It's just the poor motion portrayal of 24P (strobing). Motion judder is a change in the apparent velocity of objects in motion caused by 3:2 pulldown in the telecine process (going from 24P to 60i), or by any change of frame rates from one speed to another where one speed is not a multiple of the second speed.

About the only thing you can do to minimize the poor motion portrayal of 24P video is to decrease the shutter speed as much as possible... (1/60, 1/48), increasing blurring of objects in motion. Fast shutter speeds freeze fast motion, making sharp edges. Objects in motion will stutter instead of smoothly blurring as they move.

Of course, you should minimize panning, tilting or zooming to minimize the effect.

Tom

[Thomas Smet]

Where visual effects is concerned 60p will never become the norm. Nobody wants to rotoscope or render all those extra frames when they are not needed. Time is money in Hollywood and it is a waste of time and money to process 2.5 the amount of frames just to make it easier for people to shoot. Shooting at 24p takes great skill and was never designed for any person to just grab a camera and go to town. Shooting 24p is an art and is like painting with a brush. You want natural movements not the clumsy jerky style of shooting people are used to with video cameras. Just because you can get away with it with a video camera doesn't mean it is good shooting.

The funny thing about the comment about the younger people moving away from 24p is that every film student I know wants 24p.

The framerate doesn't matter for the story. If your story is good and you know how to shoot then 24p is more then enough. It always has been and it always will be. Sure you could shoot a movie at 60p but other then making the motion extra smooth it isn't going to help the movie become a better movie. In fact in some ways it could make it worse. 24p can mask a lot of bad acting because stupid mistkes may not show up as much. With 60p you will notice every little hickup or camera flub which may distract from the story. you also run the risk of things starting to look too robotic like in 3D animation. Be carefull of trying to make things look too perfect. Perfect can sometimes be a curse and sometimes the organic approach is the best way to please the viewer.

[Evan Donn]

Originally Posted by Eric Pascarelli

We could capture 2.5 times more information, shooting film at 60fps and transferring each frame to a field of video, or a progressive frame, but this is frowned on because it "looks like video" and hence is perceived as lower quality, even though it is obviously much higher fidelity.

Well, a photograph is obviously much higher fidelity than a painting - and yet people keep painting, and buying paintings, because sometimes it's not about how accurately you can duplicate reality. There's a time for 60fps and a time for 24, and the art is knowing when to use which.

[Peter Jefferson]

24p isn't a Magic Bullet.

To shoot good 24/25p one must shoot with the mentality of slow frame with equalised shutter speeds to provide a motion blur cadence which emulates the "look" properly. Each camera has its merits and considering they're each using pretty much the same pulldown service, they SHOULD be identical in all ways (motion wise) if set up correctly.

"FRAME JUDDER in 24p. I hate it. " -- If frame judder is an issue, you either haven't set up your camera correctly, or you're not shooting correctly.

"On the Canon XL2 it's really awful during pan shots. " -- This is probably because your panning too fast, or your shutter speed is too fast for the frame rate. With Canons and the lack of near instant iris and harder ND control, the shutter is the next option available to you, bar the -3 gain setting... it's easy to get stuck in this situation.

"It's obvious noticeable judder. However on the DVX100 I find it pleasing." -- They should look no different. The DVX sets itself to the appropriate shutter however, whereas the A1 does not. Again it's easy to get stuck in this situation.

"Thus, I wonder how Sony XDCAM handles frame judder." -- They're all using the same Pulldown transport service save for the HVX 24pN.

There should be no noticeable difference. If anything, consider the information which the codec is processing, and Long GOP structure of the file itself. These all play a part in how the image is perceived and updated. The HVX and DVX are using full frame compression algorithms, HDV and XDCam use LongGOP. More than likely if you are seeing an issue, it would stem from the fact that every half second cycle is being updated which is where you're seeing this judder.

Like I said though, this can be alleviated when filmed properly. As for the EX, as it's a variable bitrate, the issue shouldn't be as pronounced as it would be in HDV because as soon as the image begins moving, the higher bitrates of the codec will kick in. DV and DVCPro should be even smoother still as they don't have GOP issues to manage.