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Some EX3 rolling shutter footage

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Nick Hill
Some EX3 rolling shutter footage
on May 19, 2009 at 7:41:43 pm

Just thought people might be interested in this footage we shot last week. It's the first time I've noticed the EX3's rolling shutter, and then only because I tried to stabilise the footage in After Effects. It was shot at 720p25, shoulder-mounted - the cameraman was just walking along. First is the original footage, then there's the version I got when I wondered "would it be worth trying to stabilise it in AE?"

The answer: No.

http://www.rainjam.com/test/EX3_rolling_shutter.wmv



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Michael Palmer
Re: Some EX3 rolling shutter footage
on May 19, 2009 at 7:54:46 pm

I don't see any issue from the shutter. What I see is a shaky operator. Obviously if you reduce the frame rate from 50i to 25p you will see more bobbles from operating hand held. This is where a good operator makes his money.

Good Luck
Michael Palmer


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Nick Hill
Re: Some EX3 rolling shutter footage
on May 19, 2009 at 8:15:50 pm

True, but it *is* handheld (and deliberately shaky). I was just interested in the way the rolling shutter is so obvious in the second clip where it's not in the first.



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Michael Palmer
Re: Some EX3 rolling shutter footage
on May 19, 2009 at 8:26:03 pm

The second video is heavily software processed using something like Final Cut Smooth Cam that tries to stabilize video with motion tracking. I fail to see your point, I don't understand how you can call attention to the rolling shutter from using a software stabilization.

Good Luck
Michael Palmer


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Nick Hill
Re: Some EX3 rolling shutter footage
on May 19, 2009 at 8:37:15 pm

Never mind. I did kind of explain the first time round. I wasn't particularly making a new point, just thought it might be of passing interest....



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Tim Kolb
Re: Some EX3 rolling shutter footage
on May 20, 2009 at 11:32:17 am

Rolling shutter is typically evident on footage where something is moving horizontally very fast. A rolling shutter is assembling the image from top to bottom so the moving item may have some distortion where the top appears to have made less 'progress' than the bottom due to the fact that the item was 'captured' slightly later on the bottom.

I've only had one situation where I saw a rolling shutter on an EX1 personally. A car was approaching me at 40-50mph as I was on the sidewalk following it...and the three or four frames when it was right beside me (about 6 ft away) was the only point where, if I go frame by frame, I can see the evidence of a rolling shutter...and it's not even present over the entire length of the car.

So...that's pretty extreme movement. It's possible that small image oscillation left in your footage is from a rolling shutter...but it isn't a manifestation I'm familiar with. Have you tried to stabilize other hand-held shots?






TimK,
Director, Consultant
Kolb Productions,


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Bengt-Goran Bengtsson
Re: Some EX3 rolling shutter footage
on May 21, 2009 at 10:57:20 am

Hi Nick and all,
It took me a couple of times of looking before I saw what I think you mean. Especially on the "blue stands" you can see a "compression" or distorted height due to the rolling shutter in combination with the fast movement of the hand held camera. You can see the same in the original pictures also but not so obvious because the object is moving. The rolling shutter is making the picture to "lean forward" when panning (and leaning backwards when object is moving fast). And when moving up and down you will compress or expand the picture in height. (Maybe my English is not correct...)
yours
BG Bengtsson


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Dean Sensui
Re: Some EX3 rolling shutter footage
on May 22, 2009 at 1:04:42 am

There seems to be some distortion of the image. I've see the same when trying to digitally stabilize footage shot with the EX1.

So my rule is: If I want a stable shot, use a stable platform. Either a dolly, Glidecam, crane, tripod, etc. If I'm going to get a hand-held look, then take what comes.

And if I'm going to shoot HD, shoot full HD: 1080p, not 720. Capture as much image data as possible right from the start.

Even material shot with a CCD has problems when trying to stabilize a shot. Motion blur will create odd-looking frames. They're stable, but they're also blurred from movement. So again the mantra: for stable shots, use a stable platform... unless there's absolutely no other choice.

Dean Sensui -- Hawaii Goes Fishing


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