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Old July 11th, 2008, 08:54 PM   #1
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Is this a rolling shutter issue or is my camera faulty??

I'm experiencing strobing artifacts in some of the footage shot with my EX1. Until now I thought it was due to the camera's rolling shutter while shooting under fluorescent lights. But yesterday it happened while shooting outdoors in the middle of the day, nowhere near any lights. Sometimes the strobing would go away after a few seconds, while at other times it would persist throughout the entire shot. The problem is not like the jellocam or partial exposure artifacts documented on various forums. It's more like a color shift that moves up and down the screen. I've posted an example here -->
http://www.mediakobo.com/watersafety.mp4
It's most noticeable when you advance the clip frame by frame.
I had the camera set to full manual during this shoot. Has anyone else experienced this?
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Old July 11th, 2008, 09:22 PM   #2
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I hate to say this, but I think I saw this once too. It happened so briefly that I almost didn't see it and it never happened a second time. However, since my EX1 lost its' ability to focus to infinity, it's now back at Sony Service. Maybe it will screw up while THEY have it.
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Old July 11th, 2008, 09:49 PM   #3
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Looks weird, but if you want advice you need to tell us all your settings.
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Old July 12th, 2008, 01:59 AM   #4
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As I remember, I was shooting 1080 30P HQ, shutter at 1/60, ND filter 2, aperture around f4, everything set to full manual (zoom, white balance, focus, iris), steady shot on, built-in camera mic only...
is there anything else that would help?
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Old July 12th, 2008, 02:16 AM   #5
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Could it be caused by the water reflection?
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Old July 12th, 2008, 07:42 AM   #6
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Looks like a florescent light issue.

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Old July 12th, 2008, 08:38 AM   #7
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It does look similar to fluorescent light strobing but 1) there weren't any lights whatsoever near this outdoor pool, and 2) even if there were, the bright sunlight would have drowned out their effect.
Here's a larger sample that shows the artifacts more clearly.
http://www.mediakobo.com/watersafety2.mp4
here you can see faint strobing bands of blue-ish and red-ish color.
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Old July 12th, 2008, 10:09 AM   #8
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What it looks like to me is that the water is reflecting the light onto the wall and the
camera is trying its best to auto white balance the color shifts of the water ripples
being projected into the scene..
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Old July 12th, 2008, 11:56 AM   #9
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It looks 100% electronic to me - I've never seen reflections cause a colour shift, and the shifts are only going one way, reflections from the water would go both. Probably worth shooting a white card and deliberately overexposing - this should prove if it is level related, and should give you more scope for experimenting before sending it back for service. Is it visible in the viewfinder during record, or only on playback?
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Old July 12th, 2008, 12:06 PM   #10
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Was your battery near the end of its life. Not sure about the EX1 but some cameras can act strange when the battery is weak but not causing a warning.
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Old July 12th, 2008, 03:07 PM   #11
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Rob, I included your links to your footage in an email to the guy at Sony Service who I'm dealing with re: my focus problems. Since I saw this once (VERY briefly) with my EX1, I'll try to get an answer from him about what he thinks is causing this. I'd hate to open yet another can of worms with this camera, but if this is happening with certain EX1's, I'd like them to know about it. Might as well have them aware of it while they have my camera in the shop......again.
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Old July 12th, 2008, 07:39 PM   #12
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Dave,
Thanks for referring this problem to Sony service. I'd really like to hear his opinion on this.
Auto White Balance was turned off but the color shifting does look like it could be related to AWB somehow. Battery life was at 80%. I saw the strobing in the LCD every time it happened during the shoot.
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Old July 12th, 2008, 08:38 PM   #13
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I don't think it's a AWB issue as the whole screen would probably "pulse" with the color changes if it was jumping between two different color balances. I'll pass along anything I get from them....if anything.
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Old July 13th, 2008, 09:22 AM   #14
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Never seen this.

One quick solution is to bring back the EX1 to that location and try it again.

If you're not seeing it anywhere else, there's something unique to the lighting in that area.
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Old July 13th, 2008, 07:24 PM   #15
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I was able to recreate the issue in my office this morning. It seems to be triggered by a combination of bright light and white balancing, although I can not confirm this without further testing. Changing the shutter speed from 60 to a higher setting, such as 250 or 500, and then returning to 60 nearly eliminates the effect, but the problem returns after switching the camera off and on. Changing the Flicker Reduce setting from "on" to "auto" seems to have minimized the issue. Maybe that's what was causing the effect?
Here's another sample I took in my office.
http://www.mediakobo.com/blinds.mp4
The room lights were all turned off. Only natural light is entering the camera.
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