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Old August 25th, 2003, 11:08 PM   #1
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shooting a tv screen

I was wondering how I can go about getting rid of the lines that appear when I shoot a television screen. Do I need to play around with the settings on the camera or is there some type of filter that will correct the problem?

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Old August 26th, 2003, 12:10 AM   #2
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The solution depends on the camera you are using. The Canon GL2 and XL1S have a feature called "Clear Scan" which alters the shutter speed ever so slightly to enable you to compensate for the refresh rate of the monitor.

If your camera does not have such a feature you will have to adjust your shutter speed to come as close as possible to eliminating the monitor's rescan lines. You may also be able to adjust the monitor's refresh rate to further help.
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Old August 26th, 2003, 12:36 AM   #3
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Yeah, the easiest solution is to just shoot a LCD monitor, but shooting a TV is easy, beacuse they have a 60hz refresh rate, so as long as your at 1/60 shutter, it will be fine. Same with computer monitors, most are like 72hz and above, but you can change the settings and take it down to 60hz, and shoot at 1/60, and it will be alright. You'll probably still get a little thin line though...
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Old August 26th, 2003, 11:36 AM   #4
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Clear Scan still works best. Using a 60th shutter will work but almost always will result in the "line". It's there because the shutter on your cam and the refresh of the set are not sync'ed. So although you will still have a line, at least it won't be moving!
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Old August 26th, 2003, 11:48 AM   #5
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"getting rid of the lines..." normally there is only one line or a fraction of a line if you shoot NTSC at 1/60 and PAL at 1/50. "Clearscan" simulation is possible on allmost all cams having variable shutter setting (in AE mode). So e.g. with a VX2000 there is no problem to perfectly shoot a 75 Hz CRT computerscreen.
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Old August 26th, 2003, 01:15 PM   #6
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If it's a TV screen, shoot at a shutter speed below 1/60 of a second. A speed of 1/30 or 1/15 of a second is fine. Speeds lower thana 1/15 of a second may be blurry.

Computer monitors (CRT) do best with clear scan.
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Old August 26th, 2003, 02:58 PM   #7
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For shooting TV and computer CRT screens with vx2000 (and most other cams) see http://www.bbctraining.co.uk/onlineCourse.asp?tID=5173&cat=2781 and go to "open guide 3"
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Old August 26th, 2003, 05:38 PM   #8
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I'm using a sony dcr-trv30. I don't think I'm able to adjust the shutter speed on it.
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Old August 26th, 2003, 07:50 PM   #9
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There's a color slow shutter (or super nightshot) for you to try for fun. I doubt it will turn out nicely though.
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Old August 26th, 2003, 09:00 PM   #10
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Dennis,
All video cameras that I've ever seen have adjustable shutter speeds. Some have a greater range of speeds than others.

Check your manual.
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Old August 27th, 2003, 03:53 AM   #11
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Indeed Dennis, TRV30 is maybe fully automatic, so the aperure can't be locked (aperture priority). You need an LCD screen or follow Jeff's suggestion, but keep in mind that apart from the motion blurr with slow shutter settings, you reduce the vertical resolution by 50%, and in addition to that, most CCD structures show some blooming (leakage effects) due to the longer integration times and the "dead" (or weak) pixels tend to show up in the dark area's (fixed pattern noise). If it concerns a TV screen and you have the chance that the "line" (at 1/60)is not moving up or down. you can try a number of times the rec button on and off untill the line is hidden in the vertical retrace part of yr pic,
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