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Why are all camcorders useless??

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Sean Herbert
Why are all camcorders useless??
on Jul 30, 2011 at 5:07:06 pm

I'm looking for a new camcorder - something compact for traveling, as my 7D and Panasonic P2 are too cumbersome.

Anyway - every single HD camcorder I've looked at shoots in AVCHD. But AVCHD goes jerky/juddery during any sort of panning. This is a known issue - any time you try to pan horizontally, the picture is jerky - I assume this is because AVCHD is long GOP & highly compressed, and it has trouble with obtaining (or retaining) the all of data in a horizontal pan.

See here:
http://www.google.ie/search?q=avchd+panning&ie=utf-8&oe=utf-8&aq

Anyway - the only other option is HDV, which isn't full HD.

Does anyone else find this absolutely bizarre?? There are actually no options for me! Everything is AVCHD, and if I ever need to film any sort of pan (which is one of the most common movements), it'll look juddery.
I found this out the hard way by purchasing a Panasonic TM900 - I ended up returning it to Amazon for a refund after I tested it out - juddery & jerky when I tried to pan on it - zooms, etc, were all fine, as were static shots.

WTF?

Feedback welcome; I really hope I'm way off the mark here.


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Mark Suszko
Re: Why are all camcorders useless??
on Jul 30, 2011 at 11:00:25 pm

AFAIK, all pans are horizontal.
Tilts are vertical.
Dolly moves in and out
and trucks go right and left.

Sorry to be such a stickler about it but there's a bad habit growing of people casually using "pan" when they mean a tilt or even a zoom or dolly. If we don't keep up a standard vocabulary for these moves, pretty soon nobody will be sure what actual move anybody is talking about. Back to answering your comment:

You can love or hate this codec, but the issue was here long before the codec. Film camera operators have long known this issue and they developed a set of "speeds" for making their moves that minimizes the effect. It takes real discipline to consistently make the panning move at the "right" speed.

You may also want to look into some of the plug-ins that claim to repair this "jello effect" in post.


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Rick Wise
Re: Why are all camcorders useless??
on Jul 30, 2011 at 11:26:03 pm

Mark, the judder effect is I believe quite different from the jello or rolling shutter effect. The jello comes from the scanning of a CMOS chip during a pan. The judder comes from moving the camera horizontally faster than one should for the subject. Subjects such as vertical picket fences are the devil to shoot, while a large flat wall poses no problems.

There is a tutorial on how to remove the Jello effect here: http://lesterbanks.com/2010/03/rolling-shutter-fix-in-after-effects-with-no.... The "free" method for After Effects is long and when working with a lot of footage shot with this problem it would be more effective to buy one of the plug-ins.

The only cure for judder is practice panning slowly enough to prevent it. 24p is worse than 30p, which is worse than 60i. When shooting product shots in 35mm one trick we latched onto was to shoot at 60 frames/second. Then transfer to video at 60 fps. Since we were transferring to interlaced video, the result was that each film frame was one field of video, providing twice as much visual information as we would have had shooting 30 fps. We never shot 24fps for these table-top shoots because the 3-2 pulldown at the transfer (to 29.97 frames/second, which is what video runs at,) added artifacts.

Rick Wise
director of photography
San Francisco Bay Area
part-time instructor lighting/camera
Academy of Art University/Film and Video (grad school)
http://www.RickWiseDP.com


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Sean Herbert
Re: Why are all camcorders useless??
on Jul 31, 2011 at 6:20:45 am

Thanks for the replies, guys.

I looked at that video - I don't have that "jello" issue at all. It's definitely judder.

I tried panning slower and sure, it's not as bad, but it's still there - it's horrible!

I guess what baffles me is why the hell AVCHD is such a standard format, when it has this glaring issue?

My 7D shoots h.264 .mov files, and doesn't have this judder during panning at equal speed - so it's not as if smooth panning is impossible to achieve with highly compressed full HD files!

Unreal... I never had this issue with MiniDV.


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Jan Crittenden Livingston
Re: Why are all camcorders useless??
on Aug 1, 2011 at 12:31:19 pm

Hi Sean,

Your 7D is also recording in AVCHD, just another version. The issue is your shutter speed if you have slowed down your pan and it is still too juddery. The smaller cameras may not allow for control ouver shutter speed.

Take a look at the collection of footage here:http://vimeo.com/groups/72874/videos/sort:alphabetic

They were all taken with the AF100 camera, all recorded to AVCHD, and there is not an issue with motion. So it comes back to the movement of the camera by you, i.e., you are moving it too fast, or your shutter speed needs to be slower to allow for more motion blur.

Your reference to the poster that complained about the codec is not a scientific post, thus it is not well documented as a problem. What is documented in that post is that a person is having a learning curve issue on how to shoot with a camera and is not reflection on the codec at all, but more on his inabilities.

Best,

Jan

Jan Crittenden Livingston
Product Manager, AVCCAM, AG-3DA1, AG-AF100
Panasonic Broadcast & TV Systems



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dave cochrane
Re: Why are all camcorders useless??
on Oct 27, 2011 at 3:59:16 am

Woah! Way to go there with a diplomatic post about someone potentially using your company's products there, Jan.

For brand representation it might have been better to point the individual toward the knowledge he might lack, or some form of training that would address the issue. Pointing out the shortcomings of your customers is never, ever a smart move.


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Shannon Baker
Re: Why are all camcorders useless??
on Jan 30, 2012 at 10:54:08 pm

How did Jan not address the issue? She said it was shutter speed. She said that you could fix the problem by changing the speed. Of course she's going to reference her product as she probably knew the website by heart. She didn't say he couldn't make the 7D work and the Panny was better, just saying they use the same codec but yet she had proof the Panny could do it, so the 7D could too.

As for the subject at hand, I personally don't like AVCHD either. I'm a DVCPro HD fan myself...but use both. Why hasn't everyone moved to P2? Ask yourself, will you pay that much for the cards? I did...and love them, but a lot of people won't. It doesn't end there either...as you need more storage space too. Try transferring data to a client. It takes a hard drive! Point I'm trying to make is that I believe cost in general is one of the reasons we have the HDV's and AVCHD's of the world. But that's just my opinion. ;)



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Ralph Savage
Re: Why are all camcorders useless??
on Jul 15, 2012 at 11:05:38 pm

Rick,

I just read this post about camcorders using the AVCHD format.



About 14 months ago I purchased a Canon XA10 camcorder which records in AVCHD.



I had to shoot a room for a realtor and mounted the camcorder on a tripod with the image stabilization OFF.



I then began panning from right to left and then back from left to right. When I played the clip back on my computer, I noticed that on a fairly regular interval, the panning would STUTTER or SKIP for a brief moment.

I don’t know if this is a problem with the camera or if it is just a quirk associated with AVCHD.



My camera was set to MXP (High quality 24mbps), PF30 frames per second, at a shutter speed of 1/60 second.



I thought this would be fine, but are these settings the cause of the problem?



My camcorder can shoot at 60i, PF30, PF24 and 24P. I am shooting for the web and thought I was doing everything right.



I appreciate your feedback/advice.



Is there a format that wouldn’t do this? There are so many PRO cameras shooting AVCHD.



Thanks.


Ralph


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john sharaf
Re: Why are all camcorders useless??
on Jul 15, 2012 at 11:08:41 pm

Pan slower and/or use a wider lens. Settings sound correct.

JS



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Rick Wise
Re: Why are all camcorders useless??
on Jul 15, 2012 at 11:55:31 pm

I agree with John. On some cameras it is possible to set a wider shutter angle, which will help to add a more normal blur as you move. One other possibility is to shoot at 60i -- the stutter problem is then less acute. Since you are panning empty rooms for web display of real estate, there probably is not a whole lot to gain by trying to shoot 30p so the 60i should work. Indeed for that very reason when I shot just such a project for a client, I did shoot in 60i and it worked just fine. (The worst setting for web use would be 24p. More stutter, and more artifacts from the 3/2 pull-down conversion to 30 fps.)

Rick Wise
Cinematographer
San Francisco Bay Area
http://www.RickWiseDP.com


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Ralph Savage
Re: Why are all camcorders useless??
on Jul 16, 2012 at 6:02:13 pm

I'll have to try the 60i setting. Still, the realtor is going to post the video on the web-- will 60i work on YouTube or a website?

Also, I don't understand what SHUTTER ANGLE is. I understand shutter speed and frames per second. I don't know if my camcorder can adjust the angle of the shutter.


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Rick Wise
Re: Why are all camcorders useless??
on Jul 16, 2012 at 10:48:24 pm

Shutter angle is a way to describe how closed or open is the shutter. It does not look like your camera has that possibility. As for 60i on YouTube, I'm pretty sure it will -- but shoot a quick test and upload it to make sure...

Rick Wise
Cinematographer
San Francisco Bay Area
http://www.RickWiseDP.com


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Ralph Savage
Re: Why are all camcorders useless??
on Jul 17, 2012 at 4:50:39 am

Rick,

Thanks for the advice. I'm going to do just that.


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David Eaks
Re: Why are all camcorders useless??
on Jul 17, 2012 at 12:06:22 pm

As I understand it, Shutter Angle describes the relationship between frame rate and shutter speed based on the real physical rotary shutter of a film camera, unlike our digital cameras, but the concept still applies. For example, to change the "angle" of 30fps video, you would simply adjust the shutter speed. I couldn't find the specific video that helped me figure it out but I found another one that works. At about 1:30 there's a good graphic that makes the concept of Shutter Angle easy to understand. There's also a link to the guys website in the description for more reading if you're interested.







I agree with the suggestions for shooting 1080 60i but it might be worth trying out 720 60p as well. While I'm not really experienced with 720 60p (or is it "p60" if someone could clarify the meaning of where the letter is placed, I would be most grateful), I think you can shoot at 1/60 shutter speed to get the "normal" amount of motion blur (and same exposure levels that you'd get at 1080 60i 1/60 shutter). As opposed to U720 60p with a shutter speed of 1/120 (1/125) which would be 180 degrees, for the smoother motion of 60fps and the crisp low motion blur of higher shutter speeds.

In consideration of panning the interior of rooms, I think you would want the least amount of jitter and as crisp and low motion blur images as possible. Seems like 60p and as high of a shutter speed as you can get, light permitting, fits the bill. Thats my theory anyway, FWIW.


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Paul Reilly
Re: Why are all camcorders useless??
on Sep 23, 2012 at 2:28:00 pm

There have been a variety of causes discussed to explain pan-judder (shutter angle, the AVCHD spec itself, rolling shutter, or simply the guy panning too fast cos of his inabilities! Loved that one). I want to point out another cause which certainly CAN occur (happened to me on a multi-camera shoot). If your editor is set to a different frame rate from the camera, then it will perform a crude type of frame rate conversion; essentially it will either drop or duplicate frames to force it in. So if you accidentally film at 30fps, but your editor timeline is set up to 24 or 25 fps, the editor will drop roughly every 6th frame when you import.

You won't even notice this on stationary scenes or just dialogue, but it will really jump out at you when you...... PAN.


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Robert Hosking
Re: Why are all camcorders useless??
on Jul 25, 2014 at 9:28:53 pm

I know EXACTLY what you're talking about. The video pans fine in the computer editor (for me Premiere) but stutters when you upload to YouTube. I have tried a lot of different combinations of files from mpeg to MP4 to AVI to blah blah blah and every variation within, but still get stuttery pans when viewed on YouTube. Super frustrating. And all of these comments about skill and refresh rates are hogwash. I just think cheaper camcorders and cameras can't do a smooth pan. No idea why. I have a DSLR Nikon Coolpix P500 and a Canon Vixia HF R20. Both are not top end cameras and neither create a smooth pan once edited and uploaded. Someone needs a punch in the face for not giving me a smooth pan online. May have to go back to film.


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ian ferguson
Re: Why are all camcorders useless??
on Oct 20, 2014 at 2:12:22 pm

if the video plays back fine in the device that took it you need to look elsewhere.
since it plays back fine in your editor then it's clearly not the camera, editors dont invent frames but players may drop frames if they cannot keep up.

as for the original question, i didn't think the gop was a fixed value (happy to be educated otherwise) i was under the impression that if enough was changing you may only get I frames so unless the pan is too fast for the creation of these you should get no jumps.

very new to video so could be way out, but trying to get my head round it all, tell me if i've got it all wrong.


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