What do you think this is? Rolling shutter issue? at DVinfo.net

Go Back   DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds

Sony XDCAM EX Pro Handhelds
Sony PMW-300, PXW-X200, PXW-X180 (back to EX3 & EX1) recording to SxS flash memory.


Reply
 
Thread Tools Search this Thread
Old December 9th, 2007, 10:22 PM   #1
Trustee
 
Join Date: Jun 2004
Location: Shibuya, Tokyo
Posts: 1,381
What do you think this is? Rolling shutter issue?

After shooting around late at night with EX1, felt amazed with the low light situation (the best ever after various affordable cams), I thought this one one of the shot that demonstrates the amazing capabilities of EX1 with 1080/24p over 30 frame and the light sensitivities...., but I found out in the post, there is something wrong when a man with bag crossed in front of the camera. The shape of the taxi behind gets distorted.

Anyone can suggest to make it not happen?

http://web.mac.com/kakuito/KakugyoBl...1_study_1.html
Kaku Ito is offline   Reply With Quote
Old December 9th, 2007, 11:23 PM   #2
Trustee
 
Join Date: Feb 2006
Location: USA
Posts: 1,684
I can't see what you are talking about. Is this the yellow taxi that changes shape? When? What guy with a bag?

Sorry I just don't seee anything. maybe i'm looking in the worng place.
Leonard Levy is offline   Reply With Quote
Old December 9th, 2007, 11:27 PM   #3
Regular Crew
 
Join Date: Aug 2003
Location: Asheville, NC
Posts: 47
I see what you're talking about, Kaku. It's got nothing to do with rolling shutter. It's actually the lens breathing because it's on auto-focus. The moment the man crosses in front of the camera, you can see the focus plane change from the taxi to the foreground as it searches for something to focus on. This is certainly weird looking, but again has nothing to do with the rolling shutter.
Pasty Jackson is offline   Reply With Quote
Old December 9th, 2007, 11:27 PM   #4
Major Player
 
Join Date: Jun 2006
Location: Studio Alnitak, Melbourne, Victoria, Australia
Posts: 640
Images: 3
I've watched that clip many times and still haven't seen the artifact you have noted; difficult to precisely identify which is the man-with-the-bag, since there are many. Timecode is a useful thing. I do note that the taxi arriving isn't distorted and that the taxi in the rear moves as someone gets in or out. A stationary object cannot be distorted by a shutter (rolling or otherwise).
Serena Steuart is offline   Reply With Quote
Old December 9th, 2007, 11:33 PM   #5
Major Player
 
Join Date: Jun 2006
Location: Studio Alnitak, Melbourne, Victoria, Australia
Posts: 640
Images: 3
Quote:
Originally Posted by Pasty Jackson View Post
I see what you're talking about, Kaku. It's got nothing to do with rolling shutter. It's actually the lens breathing because it's on auto-focus. The moment the man crosses in front of the camera, you can see the focus plane change from the taxi to the foreground as it searches for something to focus on. This is certainly weird looking, but again has nothing to do with the rolling shutter.
Are you speaking of taxi 1125, which bobs as it stops. Wasn't the camera on manual focus?
Serena Steuart is offline   Reply With Quote
Old December 9th, 2007, 11:41 PM   #6
Regular Crew
 
Join Date: Aug 2003
Location: Asheville, NC
Posts: 47
Ok, just watched it again. The area in question is early in the clip, just before the taxi enters the scene. You can see the focus plane changing at that moment, but it doesn't change as dramatically as I assumed... it does look to be manually focused. It is a strange anomaly, but I'm still quite sure it is unrelated to the rolling shutter.

Theory: the man that passes in front of the camera is, firstly, out of focus - which essentially blurs him. Secondly, he is swinging his arms as he walks in front of the car. The movement in the blurred foreground makes the car look distorted. It's similar to closing one eye, looking at the horizon, holding a pencil up horizontally in front of your eye, and moving it up and down while still focusing on the horizon... the horizon around the pencilo seems to bend and distort.

Just a guess that it was pure circumstance and not shutter-related. Essentially, light diffraction.
Pasty Jackson is offline   Reply With Quote
Old December 10th, 2007, 12:15 AM   #7
Regular Crew
 
Join Date: Aug 2003
Location: Asheville, NC
Posts: 47
Here's a simplistic, but easy to understand example:
http://www.ngsir.netfirms.com/englis...ffraction2.htm

Light waves (or rays) react in the same manner when an obstacle is introduced.

And... one more cheesy example:
http://www.exploratorium.edu/snacks/diffraction.html
Pasty Jackson is offline   Reply With Quote
Old December 10th, 2007, 01:21 AM   #8
Trustee
 
Join Date: Jun 2004
Location: Shibuya, Tokyo
Posts: 1,381
Okay, right now I don't have the time to read all of your responses, but this wasn't shot with autofocus. I was playing around with the focus between the people and the taxies. But no autofocus. As matter of the fact, I couldn't figure out to do autofocus until later (didn't know about the ring slide function).

If this thing gets figure out, EX1 should be really excellent.

I will look into more clips to see if any similar thing happened but over all, EX1 shows its ability to shoot video that other cams would have hard time.

And please, don't take it personal people. I'm not attacking EX1 particularly. I understand people don't want to hear about bad things to new star in the industry, but it is good to know how to avoid these things. The issue looks like similar problems I had with HV20 that the picture becomes wobbly, like elastic (excuse my limited expressions here).

I don't know what happened to all of that "you are greatest" and all that encouragements when I provided FX1 and Canon cam clips. I got a person posting "disturbing" on to my blog.
I think I'm going to quit all of this effort now.
Kaku Ito is offline   Reply With Quote
Old December 10th, 2007, 01:32 AM   #9
Trustee
 
Join Date: Jun 2004
Location: Shibuya, Tokyo
Posts: 1,381
Quote:
Originally Posted by Pasty Jackson View Post
Here's a simplistic, but easy to understand example:
http://www.ngsir.netfirms.com/englis...ffraction2.htm

Light waves (or rays) react in the same manner when an obstacle is introduced.

And... one more cheesy example:
http://www.exploratorium.edu/snacks/diffraction.html
Pasty, that's a good one.
Kaku Ito is offline   Reply With Quote
Old December 10th, 2007, 01:33 AM   #10
Major Player
 
Join Date: Nov 2007
Location: Los Angeles, CA
Posts: 498
Ito,

I think that this effect would happen with any camera, not just the EX1.

I think there is nothing to be concerned about.
Eric Pascarelli is offline   Reply With Quote
Old December 10th, 2007, 02:28 AM   #11
Major Player
 
Join Date: Jun 2006
Location: Studio Alnitak, Melbourne, Victoria, Australia
Posts: 640
Images: 3
Quote:
Originally Posted by Pasty Jackson View Post
Here's a simplistic, but easy to understand example:
http://www.ngsir.netfirms.com/englis...ffraction2.htm

Light waves (or rays) react in the same manner when an obstacle is introduced.

And... one more cheesy example:
http://www.exploratorium.edu/snacks/diffraction.html
No, diffraction isn't relevant at this scale! Certainly not the appropriate phenomenon.

Don't think anyone is upset if there is a problem with the EX, which of course people want to know about. It's just that this doesn't look like a problem.
Serena Steuart is offline   Reply With Quote
Old December 10th, 2007, 02:45 AM   #12
Trustee
 
Join Date: Jun 2004
Location: Shibuya, Tokyo
Posts: 1,381
Even if there's an issue with rolling shutter (I'm not saying there is at this moment then), EX1 seems to overcome many other affordable HD cam issues, so I don't think it will influence the popularity at all.

With my dog clip, you can see some skateboard video shooters would come up with some great footage, even at night at low light situation.

The noise level don't look that much problem when the gain was up and the stabilizer works really well, too. I think that should be helping the compression a great deal.
Kaku Ito is offline   Reply With Quote
Old December 10th, 2007, 04:31 AM   #13
Inner Circle
 
Join Date: Oct 2001
Location: Honolulu, HI
Posts: 2,053
Kaku...

That EX1, from this first impression, looks very good in low light.

Right now I'm still shooting with an HVX-200 but was looking at the EX1 as a second camera for the fishing show. In fact, if it does well enough, it will probably be the primary camera since it records a lot more material per gigabyte at 1080p30 than the HVX.

BTW, I'm working with Audy to do a bunch of production work, and he is also joining the company that produces the fishing show. If we're lucky we can get a chance to look at a demo EX1 from Sony.
__________________
Dean Sensui
Exec Producer, Hawaii Goes Fishing
Dean Sensui is offline   Reply With Quote
Old December 10th, 2007, 05:10 AM   #14
Major Player
 
Join Date: Nov 2007
Location: Finland
Posts: 317
At the risk of sounding stupid. It looks to me that the camera is moving to the left simultaneously as the man passes in front and this makes the taxi look like its skewing because it stays in the frame longer then one would expect if the camera would have been stationary. If the man had not passed the camera at this point I doubt there would be anything funny looking in the taxi.

The footage looks really nice!! Would love to see more!

Sami
Sami Sanpakkila is offline   Reply With Quote
Old December 10th, 2007, 05:32 AM   #15
Regular Crew
 
Join Date: May 2006
Location: Portugal
Posts: 140
my bet is on the mpeg compression... that element on the frame may be interpolated.
Sergio Barbosa is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 07:56 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network