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-   -   Devil's Jello anyone? (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/109972-devils-jello-anyone.html)

Dave Elston December 11th, 2007 09:41 AM

Devil's Jello anyone?
 
Hi EX1-owners,

First I want to point out this is not an attempt to flame/troll/insult or otherwise disrupt the good & well-meaning manner of this forum and its members. This is purely a thread raised due to technical curiosity (thats how my mind works).

OK,

I was reading about some Canon HV20 rolling shutter 'problems' users are experiencing at this blog...
http://prolost.blogspot.com/2007/05/...g-shutter.html

And a recent example has been posted to youtube which really is pretty nasty:
http://uk.youtube.com/watch?v=0qC0_nIUq9s

All I want to know is if any EX1 user is able and willing to reproduce these conditions (hard-mounted to a revving motor-vehicle) to gauge how well the Exmor chips hold up to similar vibration with regard to the jello effect ?

Simple test I think, and I would hope for a reasonably happy (or atleast more watchable!) result.
I know that, from other threads, handheld shots seem to be fine in most practical circumstances - this is more of a specific grip test to see where the no-go-zones for this camera might be found.

This may also be a good thread to post any other tips or pitfalls on how to minimise or avoid severe rolling shutter effects as they manifest themselves (if this issue ever gets that bad with this camera?).

TIA
Dave.

Craig Seeman December 11th, 2007 10:47 AM

How about the EX1 mounted to a plane doing rolls?

This is on the Sony site
mms://sony.wmsvc.vitalstreamcdn.com/sony_vitalstream_com/Patty%20Wagstaff%2010G%20Demo.wmv

You'll have to cut and paste since it's an mms link.

Dave Elston December 11th, 2007 11:02 AM

Yep, pretty convincing that stuff!

Although I don't have much knowledge of how the EX1 was mounted (hard or soft suspended ?) it certainly seems to hold up to the Gs.
The question is more about the effect of short-period vibration from an engine in close proximity (I'm no aeronautic expert so can't comment on the cockpit environment).

The test I'd like to see was something a bit more 'down to earth', maybe a bonnet cam (driver facing) or like that shown in the HV20 example - a simple hard mount to chassis/bodywork with some revving or maneuvers.

Not digging for an issue if there is none, but prefer to know where not to put my spade so-to-speak!

Thanks,
Dave.

Gregger Jones December 11th, 2007 11:20 AM

Why would this Jello be only for the Devil?
 
So I took the Ex and played around based on the things you were concerned with. I had two questions to answer to myself. What is a rolling shutter on a digital camera? Lets face it, Digital is mimicking film these days. And how does it reproduce that look? So once I figured out that there is truly no rolling shutter and only the illusion of what one would look like in any given situation, I saw what it was you were talking about. I did not really see a wobble in the footage with the shutter off up to about 180 deg. After that you get a little of that "Jello". Also, it didn't seem like something that was wrong. It looked like an effect. So I guess the question is do you need a camera that is going to act more like film or more like video? I don't think you have to strap it to a revving motor to figure this out. If someone was worried that most of the shooting they were gonna do involved being attached to something that vibrates dramatically, then maybe they would choose a tool accordingly. It was fun figuring that out and if you have any pressing issues about it let me know. My final thought is that it would not be a hinderance but rather a bit of knowledge one would test with their own circumstances before ever pulling the trigger.

Dave Elston December 11th, 2007 11:38 AM

Thanks for taking the time to test this Gregger !

Of course all the points you make about try-before-you-buy or try-before-you-shoot are valid and sensible suggestions.

So you would be happy to use the EX1 in this type of environment (avoiding low shutter speeds, as noted) and expect to come away with some useable footage (unlike the HV20 example!) ?

Like you say, having confidence in the ability to get a job done is as much about knowing when NOT to use a tool as knowing when it fits the bill.
In this case it sounds like another one to notch up for the Exmor!

:0)
Dave.

Gregger Jones December 11th, 2007 12:20 PM

I would say it depends on the specifics of the situation. The camera seems to be very adaptable.

Charles Young December 11th, 2007 04:42 PM

I used to use an A1U and it had "Rolling Shutter"

I looked for the footage but was not able to find it.

Simulate the footage by selecting the highest shutter speed, 1/10,000 for A1U. Drive down the interstate in the fast lane at or just above the speed limit, 75MPH or so. Frame the oncoming traffic fast lane perpendicular to the flow of traffic. A box truck or semi-trailer would be noticeably slanted. I found it disturbing.

Would be nice to see someone with an EX1 do this trick. Maybe shooting out the window of the driver's side backseat would be wise.

Alister Chapman December 12th, 2007 06:50 AM

Who the hell is going to shoot stuff like that, I mean come on, thousandths of a a second shutter looking across fast moving traffic while driving at 70mph.

Let's be realistic here, I'm sure if you try hard enough you'll find lots of issues with any camera. The Jello effect may be a result of image stabilisation as well as any shutter issues. These unreasonably extreme tests are crazy. What really matters is whether it works correctly in the real world.

Joel Chappell December 12th, 2007 07:32 AM

No Better Test for Vibration
 
I was in the AF for 21 years. I've worked on airplanes, ridden in airplanes, etc. I can tell you for very sure, just the taxi down the runway in that airplane on the video is much rougher than ANY car ride.

Not to mention the barrel rolls, quick snaps, dives, climbs etc. that she did.

I don't know if you've seen other video made in an airplane pulling 10g's but I have. It is common to see the video blink, jitter and jump.

That video is nothing short of amazing.

Dave Elston December 12th, 2007 08:10 AM

Thanks for the expert input Joel, I was hoping for some more insight into Jody Eldred's POV clip (the Patty Wagstaff demo) - would be great to see this at original resolution, or maybe coming to an Imax soon?! ;)

Alister, please don't take this as a flame, the point of the thread is to guage just how 'extreme' this camera can go before RS (or any other) issues manifest themselves - if anything, to simply avoid losing sleep (or worse a paying client!)
Of course I'm interested in real world performance as well, and this is proving to be one heck of a camera for the majority of work most of us would expect to do.

Just occasionally there are unusual/extreme jobs that come up where I would like to be able to know (either way) if the EX1 will still fit the bill - so knowing it's limits is part of the equation. We are dealing with new technology afterall, and while it is still early days, it seems the Exmor chips really are several generations ahead of those used in earlier CMOS camcorders, good job too.

Like you, I hope people do continue to treat the thread with the fair & balanced view that is required as I believe there is genuine value to it.

Cheers,
Dave.

Charles Young December 12th, 2007 03:53 PM

WoW! Thanks for your wonderful input on this subject.

Now on to address the issue. At my last job I was interested in capturing items traveling at 1000fps through a 300 foot FOV(3-5 frames). I understand this is not typical but on occasion is "The Subject". I would like to use this camera to do sports work, it would involve subjects moving rapidly through the FOV and rapid panning. I am thinking this camera may not work under these circumstances.



Quote:

Originally Posted by Alister Chapman (Post 791118)
Who the hell is going to shoot stuff like that, I mean come on, thousandths of a a second shutter looking across fast moving traffic while driving at 70mph.

Let's be realistic here, I'm sure if you try hard enough you'll find lots of issues with any camera. The Jello effect may be a result of image stabilisation as well as any shutter issues. These unreasonably extreme tests are crazy. What really matters is whether it works correctly in the real world.



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