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-   -   Unwanted judder 720/25p (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/86736-unwanted-judder-720-25p.html)

Dennis Robinson February 17th, 2007 12:05 AM

Unwanted judder 720/25p
 
Hi,
I am far from happy with the progressive judder with my JVC HD111 camera. I have studied the forums for help with a way to shoot without introducing judder and dont know what to do. I have had the camera checked to be told that it is normal progressive footage so I guess I have to practice till I can get footage that is usable. It shoots SD50i great and I feel that is the main use of the camera as I produce TV commercials and it will be a while till I will be using HD. Apart from that, I can see no way that the footage i am taking can be used because of the judder. If I fix the camera to a tripod and frame an intersection, cars going left to right or vice-versa judder. I have been told this is normal. I need to learn to track moving objects like cars etc and pan really slow. I have been advised to turn off motion smoothing but it doesnt make any difference. Is there any settings/ filters/ I can use in FCP to make it smoother. I am open to any ideas. I have only had the camera 2 months and dont want to sell it for a Sony Z1 or smaller form cam. I also dont wish to drop a few grand either in such a short time. I am in PAL and have been told that shooting 720/30p will help but then I have to find a way to convert it back to 720/25p for PAL. Hope you can help.

Antony Michael Wilson February 17th, 2007 05:21 AM

Well, if you want the film look by shooting progressive, there's no real solution other than adapting your shooting style. As you say, tracking your subject helps and so does careful depth of field management. I'm sure you're aware that one of the many reasons film looks different is the shallow depth of field, which is a real bonus on low frame rates because the blurring helps to mask the judder. If you have crisp frame from a video camera where everything is in focus then movement - particularly horizontal - will cause judder. I'm sure there's plenty of stuff on these boards about minimising judder via shooting technique.

The other obvious solutions are:

Upgrade to at least the HD200 so that you can shoot 50p (which will mean HD without the judder but a different aesthetic).

Try shooting at 1/25 shutter rather than 1/50, which will result in a more smeary image but some of the judder will go away. On recent documentary we used 1/25 for some shots from a moving train and it worked perfectly to smooth out the motion.

Dennis Robinson February 17th, 2007 05:37 AM

Quote:

Originally Posted by Antony Michael Wilson
Well, if you want the film look by shooting progressive, there's no real solution other than adapting your shooting style. As you say, tracking your subject helps and so does careful depth of field management. I'm sure you're aware that one of the many reasons film looks different is the shallow depth of field, which is a real bonus on low frame rates because the blurring helps to mask the judder. If you have crisp frame from a video camera where everything is in focus then movement - particularly horizontal - will cause judder. I'm sure there's plenty of stuff on these boards about minimising judder via shooting technique.

The other obvious solutions are:

Upgrade to at least the HD200 so that you can shoot 50p (which will mean HD without the judder but a different aesthetic).

Try shooting at 1/25 shutter rather than 1/50, which will result in a more smeary image but some of the judder will go away. On recent documentary we used 1/25 for some shots from a moving train and it worked perfectly to smooth out the motion.


Thanks Antony,
I had no idea when I bought this camera that it would cause judder shooting HD. Most of my work is shooting TV commercials and medium pans are required inside a retail store e.g.
I have searched everywhere for shooting styles to minimise judder as I realize I will have to learn how to do it.
I just thought I would be able to shoot HD and downconvert to SD while having the footage put away for the future when it becomes the norm.
I can see now that the Sony Z1 would have been a better camera for what I do, but I really dont like the small handycam form.
The HD200 may be the way to go as you say but 50p is not supported by FCP at this time so it is pretty useless.
Does the mattbox and battery pack fit the 200?
That will be a help in the step up as I am sure I will lose a lot of money getting rid of this cam after a couple of months. In the meantime, I will try your suggestions at shutter speed and if you have any more links regarding shooting styles, please let me know.

Antony Michael Wilson February 17th, 2007 06:23 AM

Yeah that's the big issue with 24 and 25fps on any camera at any resolution. It's really unforgiving with movement - like shooting on film but worse because of the incredibly large depth of field you get under most conditions. If you have the time and money to work around this like they do on film shoots for movies then that's great but it's a little tricky for those of us further down the food chain. Having said all this, documentaries used to be shot on film with small crews and relatively small budgets and this is what I focused on before our last big project. We shot with a crew of one or two over 6 months at 720p/25 without a large budget and without the ability to plan shots in a big way. We came back with nearly 100 hours of footage and I can honestly say that we only had to ditch two shots because of judder. That's because we were very, very careful with pan speeds and any camera movement - just like I used to be on S16 shoots.

There are many far more experienced camera operators and DoPs on here who could chip in with more concrete advice on shooting styles and techniques - Post is my thing!

It seems to me that the HD200, HD250, Canon XLH1 or something from the Sony XDCAM range might be better suited to your needs than the Z1. As to FCP and 50fps, you could invest in something like the Blackmagic or AJA boards with HDSDI and HD YUV I/O. Then you could cross-convert 720/50 from the HD200 or HD250 to 1080i/50 for post. For HDSDI I/O you'll need the HD250 and/or a HDVtoHDSDI box like the Convergent HD Connect LE but with analogue HD component you're good to go with the HD200 alone. Alternatively, since you're only after SD at the moment, you could just down-convert for post and work in good old 625/50!! But remember that you can't down-convert to DV via firewire with the deck or the camera - you'll need to go via analogue or via SDI.

Post workflow isn't always as simple as it should be with these cameras!

Jack Walker February 17th, 2007 02:24 PM

I have been closely watching the background on movies and TV shows when the camera is moving or panning. The amount of judder there is quite considerable, but the way the shots are done its usually not noticeable unless looking for it.

For TV commercials I think interlaced video, especially in PAL, would look much better for the kinds of shots you say you need -- long pans and tracking shots.

By the way, a friend has a Z1 and uses it for local commericials. He is very happy with it. It has some nice features that may be helpful with what you are doing. The the JVC has its own unique features that are also desireable.

As a point of reference, I bought the HD110 for these specific reasons, all of which I realized after rigorously analyzing my possible workflows. I have divided the reasons for three uses I use the camera for.

WEB VIDEO:
1. Progressive scan native

SD DVD PRODUCTION OF FAST MOVING SUBJECTS:
1. 60p, giving both good motion and excellent freeze frames
2. 4:2:0 color in 60p SD mode, same as DVD.
3. Native 16:9

THEATRICAL SHORTS:
1. HDV 24p.
2. Impressiveness of camera to actors when setup up with monitor, matte box, battery, wide angle lens, etc.
3. Impressive look in set stills.
4. Manual controls
5. Focus control options for pro lens.
6. Heavier weight for tracking shots, jib floating, etc.
7. HDV firewire for capture in DVRack

FOR ALL JOBS:
1. Able to edit and process 720p HDV on my current system, without upgrading computer or software. (P4 3.4, Liquid 6.1/7, latest Adobe video suite, Procoder)
2. Compatible with current tripod, jib, tracking dolly, etc.
3. Using it in controlled environments where auto features and smaller size not needed.

If I were traveling I would buy a different camera, such as the Sony V1. Using a hard disk, the V1 captures both HDV (on disk) and DV (on tape) at the same time, or it can record your choice on tape.

For all-around professional live event shooting, I think the XDCAM is perfect--though much more expensive than the sub-$10,000 camera.

I should mention that I bought the wide-angle lens. Without it I wouldn't be able to use the JVC camera in the situations I use it in. The lens costs almost double the camera.

If I were to shoot a feature film, I would try to use the yet to be released Sony Cinealta F23.

Brian Drysdale February 17th, 2007 04:02 PM

Just to say that most commercials being shot here on PAL video are either being shot progressive or de-interlaced. Having said that, they're not being shot on a JVC, but high end cameras. However, you should be getting usable material unless you're doing pretty fast pans.

Lots of verticals will add some strobing on fast moves and progressive in video seems to be worse in this regard than film. I've shot 35mm film commercials in supermakets with very fast moves and we never even worried about strobing.

Dennis Robinson February 18th, 2007 08:06 AM

Thanks guys for your help with my dilemma. I feel that I will have to continue to shoot SD and maybe tackle the HD thing later when it is used for broadcast work. At that stage, I will have a better knowledge about the range of cameras available for a particular job. I spent 3 hours today trying to get a decent bit of footage from this camera with judder on every bit of it and cant for the life of me see where I can use footage like this.
It looks awful! Slow pans,.. in fact any type of movement cause judder and if JVC say this is normal for these cameras, then I will have to drop a few grand and buy something interlaced. This purchase has been a waste of money. I should have stayed with my XL1s for a couple more years.

Brian Drysdale February 18th, 2007 08:41 AM

Quote:

Originally Posted by Dennis Robinson
Thanks guys for your help with my dilemma. I feel that I will have to continue to shoot SD and maybe tackle the HD thing later when it is used for broadcast work. At that stage, I will have a better knowledge about the range of cameras available for a particular job. I spent 3 hours today trying to get a decent bit of footage from this camera with judder on every bit of it and cant for the life of me see where I can use footage like this.
It looks awful! Slow pans,.. in fact any type of movement cause judder and if JVC say this is normal for these cameras, then I will have to drop a few grand and buy something interlaced. This purchase has been a waste of money. I should have stayed with my XL1s for a couple more years.

What are you displaying your material on? Some LCD monitors don't have a high enough refresh frequency and have awful artifacts.

I've seen a "juddering" (it's actually more like a gentle flicker) on progressive with 23.93p straight into the on set CRT HD monitor. It's not a problem in the final production's delivery format because it's converted to a standard video format. However, on set you get used to it.

The only bad juddering I've had was from a faulty downconvertor converting from 24p HD to 50i SD for use on a Steadicam.

Also, what format are you outputting after your edit?

Dennis Robinson February 18th, 2007 08:52 AM

Quote:

Originally Posted by Brian Drysdale
What are you displaying your material on? Some LCD monitors don't have a high enough refresh frequency and have awful artifacts.

I've seen a "juddering" (it's actually more like a gentle flicker) on progressive with 23.93p straight into the on set CRT HD monitor. It's not a problem in the final production's delivery format because it's converted to a standard video format. However, on set you get used to it.

The only bad juddering I've had was from a faulty downconvertor converting from 24p HD to 50i SD for use on a Steadicam.

Also, what format are you outputting after your edit?

Hi Brian,
Thanks for your help. I have been watching the footage from my camera thru an LCD TV. I took the cam into a local JVC dealer last week and he hooked it up to a 46" Sony HD LCD and it was awful. He said to me as soon as he saw it. "what the hell is that"? He then hooked it into a JVC broadcast monitor and it was better but stll had judder. I admit that I only use the yellow component cable to output so that may not help. When I capture into FCP, it is so much better.
I have only exported to Quicktime and Compressor to create a movie.
The colours and detail are marvellous... even good.. I just hate the judder.
I guess what I was hoping to do was edit HD and downconvert to SD for broadcast commercials.

Dennis Robinson February 18th, 2007 09:15 AM

Quote:

Originally Posted by Dennis Robinson
Hi Brian,
Thanks for your help. I have been watching the footage from my camera thru an LCD TV. I took the cam into a local JVC dealer last week and he hooked it up to a 46" Sony HD LCD and it was awful. He said to me as soon as he saw it. "what the hell is that"? He then hooked it into a JVC broadcast monitor and it was better but stll had judder. I admit that I only use the yellow component cable to output so that may not help. When I capture into FCP, it is so much better.
I have only exported to Quicktime and Compressor to create a movie.
The colours and detail are marvellous... even good.. I just hate the judder.
I guess what I was hoping to do was edit HD and downconvert to SD for broadcast commercials.


Hi Brian,
I have posted a small clip to show the judder. It is really smoothed out after using FCP so you can imagine the flicker that used to be there before.

Dennis Robinson February 18th, 2007 09:35 AM

Here is the clip posted to give you an idea of the judder.

Bill Ravens February 18th, 2007 09:48 AM

Looked at your clip....my .o2 cents worth...that pan speed is WAY too fast for 24p.

Dennis Robinson February 18th, 2007 09:51 AM

Quote:

Originally Posted by Bill Ravens
Looked at your clip....my .o2 cents worth...that pan speed is WAY too fast for 24p.

Thanks Bill. I realize that now but is actually 25p. This footage was taken when I first got the camera and posted to show that amount of judder i was experiencing before. I have panned as slow as i can now but still get the same effect.

Brian Drysdale February 19th, 2007 10:28 AM

Quote:

Originally Posted by Dennis Robinson
Thanks Bill. I realize that now but is actually 25p. This footage was taken when I first got the camera and posted to show that amount of judder i was experiencing before. I have panned as slow as i can now but still get the same effect.

Sorry, I'm having problems with your mov files. Is your juddering on ordinary moving objects worse than you see in a film being shown on television?

Sean Adair February 19th, 2007 11:49 AM

Some things to try...
 
I just got my HD-200 (waited because 60p was importnat for me!) a few days back, so take this in stride.
Denis: I suspect that running footage through your workflow to SD television will lower the problem from your initial display from the camera to lcd. Certainly, you always have the option of recording very high quality SD with this camera at full temporal resolution (50P PAL).

For situations where keeping an HD option is important, maybe the following will help.
First, have you tried turning on the motion smoothing function? (it's definitely available on the HD-100) and in early demonstrations I saw it helped buffer the progressive look. If you look at still frames, there is a ghost doubling of image, but it isn't that noticeable on playback. This might just work for you. Interestingly, I don't see the option on the 200 - they just recommend the higher frame rate for situations with fast motion.
Another option to experiment with is dropping the shutter a notch to 1/25 instead of 50. You'll get blur when you pan quickly, but it might be more acceptable to you.
There are post options like after effects which could also smooth and interpolate the interlaced fields in those situations.
A radical approach would be to shoot your pan at half speed, and import the frames into a 50p or 50i timeline to preserve all the motion. A bit of a workflow, but once you have it down, it might not be too bad for certain key shots you need.
In any case, adjusting your cinematography technique is very important, as well as balancing your expectations. I'm pretty sure you are dealing with the realities of low frame rate progressive footage - but it's a look many people love!


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