I have a HV20 and I'll show you my wobbling... (I guess this is it) :)

has anybody called canon about the wobble thing ?

i was speaking to canon repair (irvine,CA) this AM about another camera (hot pixels) ..
i asked him about the hv20 and the wobble issue and he says this is the 1st he's heard about it ( also he's never worked on a hv20 yet) .. he asked other repair persons and said they haven't heard of it ... so now they heard of it at least once but if nobody else complains i don't think they will be any solutions ...
 
Nikon said the same thing about banding on the D200. They finally said it was normal.
But I think the fixed it.
 
donatello said:
has anybody called canon about the wobble thing ?

i was speaking to canon repair (irvine,CA) this AM about another camera (hot pixels) ..
i asked him about the hv20 and the wobble issue and he says this is the 1st he's heard about it ( also he's never worked on a hv20 yet) .. he asked other repair persons and said they haven't heard of it ... so now they heard of it at least once but if nobody else complains i don't think they will be any solutions ...
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as you'll recall, what's causing the problem is the simultaneous readout of one part of the sensor while another part is being exposed. it's cheapest in hardware cost to allow ONE line at a time to build up charge in a time related to the chosen shutter speed and then pump it out to the next stage in the image processing. that will give you rolling shutter distortion on some types of motion. the sensor produces data at the rate of one sensor image per 1/24th of a second with bursts of one line at a time. it always produces data at this rate. if it didn't, then you could get rid of the problem by using a faster shutter speed.

the most expensive thing to do in hardware is allow the ENTIRE sensor to build up charge in a time related to the chosen shutter speed and then pump that out to the next stage in the pipeline. the problem here is that it takes a lot of extra buffering space and control logic to do that. there are solutions in between, conceivably, where you buffer more than one line of the image at a time but you'd get probably wierder more blocky artifacts than using a single line.

no matter how you look at it, if you're doing the simple thing, which it looks like the hv20 is doing, you're not going to solve this problem actually at all without using completely new hardware. it's akin to expecting your dslr to be "fixed" to shoot at 24fps continuously instead of whatever it does (say 2fps). the hardware to clock out all those bits and buffer them is just not there (though this is slightly different because here you'd want to change the continuous rate not the instantaneous rate).

i have this camera. and it's annoying that it uses a rolling shutter of the least buffered kind. the camera is still very useful for most of the shooting i'd be doing though. and it's funny i had it for two months before i even noticed this as a general problem because i always use a steadicam whenever i move the camera. i only noticed it becasue i had shot some garbage footage without any stabilizer. the problem to me seems worse in cinemode (whcih i actually did notice originally).

thre are other major and much more expensive cameras which have a similar problem. one of the cameras had noticeable warping in their demo footage shown publically: worse than on the footage released to the web (you have to go frame by frame to notice it in that footage).
 
Yes, it's annoying when this sort of thing happens but as I mentioned in another thread it just forces me to change my filming habits. It does not happen all of the time and like you I never even noticed it until people started talking about it. But it is definately a good lesson learned. Now I look for it when filming and do everything I can to avoid it. The rolling shutter effect in this cam is like what kryptonite is to superman. If you do what you can to avoid it then it stands as a super performing camcorder.:thumbup:
 
I'm with Barry. If Sony can keep their CMOS cameras from producing a wobbling image, then why not Canon?
 
Barry_Green said:
It happens in my car stuff too. Much worse on full telephoto, but noticeable at full wide angle, with OIS on or off.

Right now, until someone proves otherwise, as far as I'm concerned CMOS + rolling shutter + 24p = useless for moving shots. Looks fantastic for locked-down shots, but anything with vibration in it, it completely falls apart.
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But Stu over at his ProLost blog suggests that the HV20 must be locked down to a 1/48 shutter speed for best results. Is this horrible warbling of the image only visible with the high (you say 1/250+) shutter speeds?
 
It seems that Sony's cameras also suffer from wobbling. Take a look at this: http://www.sonyhdvinfo.com/showthread.php?t=5664
I will take the liberty to quote divergent from that thread:

divergent said:
Any vertical movement is going to result in the top of the frame recording a slightly different angle of view than the bottom of the frame - this results in each field image being slightly stretched or compressed vertically relative to the same shot from a static camera. So as the camera tilts up the image is compressed, and as it tilts down the image is stretched - if it is wobbling up and down (i.e. typical handheld footage) the image will alternate between stretched and compressed creating the "rubbery" effect.
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I think that sounds like a fair explanation of the HV20's behavior. My home made stabilizer (similar to a figrig) did not reduce much vertical movement so that could be a reasonable explanation to why my stabilizer didn't do any good.
Next I would like to quote Laurence Kingston from the same thread:

Laurence Kingston said:
I got myself a Spiderbrace 2 from spiderbrace.com and the problem is fixed.
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Has anyone tried something like this with the HV20? If that is all it takes then I'm buying another HV20.
 
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Norbert said:
My home made stabilizer (similar to a figrig) did not reduce much vertical movement so that could be a reasonable explanation to why my stabilizer didn't do any good.
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I'd bet on that!

sean90291 said:
But Stu over at his ProLost blog suggests that the HV20 must be locked down to a 1/48 shutter speed for best results. Is this horrible warbling of the image only visible with the high (you say 1/250+) shutter speeds?
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I have no my unit yet (quite busy on location) but I'm sure that's the point.

And if you want to go with motion, try the 1/24th or 1/25th* of a second shutter and you should be fine with the motion blur, avoiding it with an effective camera movement handling:

All the grip personnel knows that a camera movement goes to an end (where the HV20 can shine! -- the motion blur is a minor hassle and its annoying effect can be surpassed by opposition on contrary effect**). The problem is the most part of the prosumer shooters don't shoot as a professional grip nor thinks the shooting plan as an efficient director would/should do (I'm sorry...but I should say: truly professional, where the amateurism may be away).

* 1/25@25p clip [ LINK ]

** Any psychologist can explain this, better than I, but the perception stuff is a subject of this business indeed, right?
 
This is the shutter lag problem that has been discussed elsewhere. Basically, it is a problem the way the data is dumped out of the CMOS sensor. Several DPs have returned this camera due to unfortunate artifact, because otherwise it is an awesome little camcorder. (Note: the CMOS shutter lag is not unique to Canon or this camera --- it has been rumored that the Red Camera, a high-end $$$ system, exhibits similar artifacts.)
 
"The Wobble" is awful. I thought my unit was damaged in shipping.

We should get a petition together and put it on all the forums and send it to Canon. This is unacceptable. If anything, we need to raise awareness so that future buyers could avoid this camera, or at least know what they are getting themselves into.
 
The Red most definitely does NOT exhibit this artifact. Please don't even let that rumor get started!

The very worst wobble footage I've ever seen from the HV20 was from a helicopter; helicopter vibrations drove the HV20 to the brink of insanity.

The Peter Jackson film shown at NAB was shot on the Red, and a ton of that footage was taken from helicopters. There's not a hint of wobble in any of that footage.
 
Barry, look closely at the wheel to the right in the first few seconds of the "crossing1.mov" clip from Peter Jackson's movie. It looks like wobble to me, just not as pronounced as on the HV20.
 
Barry_Green said:
The Red most definitely does NOT exhibit this artifact. Please don't even let that rumor get started!

The very worst wobble footage I've ever seen from the HV20 was from a helicopter; helicopter vibrations drove the HV20 to the brink of insanity.

The Peter Jackson film shown at NAB was shot on the Red, and a ton of that footage was taken from helicopters. There's not a hint of wobble in any of that footage.
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Hi, everybody..! First poster here...

Firstly, the Red camera DO exhibit this artifact. Not a rumor. Just not as much as the HV20. At least not as have been seen. And I don't think PJ would've been as happy about it as he is if it would've either. Check the wooden wheel as Norbert said. It does wobble. Test frame by frame the first time and you'll definitely see it. Then you'll see it everytime you watch it. Kind of like the rainbow effect on DLP projectors. You don't understand the fuzz until you see it, then it's there. All the time. Not a biggie, but it's there.

Second. PJ didn't sit at the passanger seat with a small camcorderversion of RED in his hand shooting those scenes either, now did he? I don't even understand how you can make that comparison... Of course PJ used pro stabalizing heli mounts for the shoot. Probably with the help of theese guys. Else it would've shaked like hell anyway, even without the wobbles. I'd be surprised to see the HV20 woobling in those circumstances too. As it probably goes as smooth as a steadycam, which seems to do the work...
 
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What I would like to see is a side by side PAL/NTSC comparison. I've just ordered a pal one and will be trying it out as I get it and send it back if it's as bad as some say...

I know the NTSC does the wobbles too but it doesn't seem like it does it as much.

AloysiusK, where are you from? NTSC or PAL land?!!

I figure if someone have access to both versions it would be cool to just strap them together and go out shooting. Handheld, steadycam you name it.
 
Okay, look -- the HV20 exhibits the effect severely enough in handheld circumstances that I consider it basically unusable for any level of professional work. In the PJ film, nearly the entire thing was handheld! And not shown on a 3" LCD, or a 19" TV, but blown up to massive proportions, which would serve to exaggerate the effect and make it completely un-missable. If the Red showed the jello wobble, we would have seen it.

Whether there's a tiny bit of shear or not, I'm not concerned about. It may have it, I didn't notice it, and film shears too. But I'm talking about the wobbling/stretching/jello effect. I'm saying the Red doesn't have that.
 
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