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Old April 25th, 2007, 11:58 PM   #16
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Claude - if you need to correct for the stuck pixel you can apply similar techniques to the camera's own inbuilt pixel compensation using a post program like Combustion or After Effects. Basically you need to copy information from a surrounding pixel and shift it one pixel across or down to cover the stuck pixel. You could even vary this over time if you found copying the same pixel too noticeable.


I'd be interested to know if the stepping you are seeing in the light graduations is before or after post processing. This stepping in colour reproduction is a result of imprecise 8 bit processing - basically when performing math on an 8 bit codec using 8 bit processing, you multiply the errors caused by not having millions of colours. This causes these annoying steps in smooth colour graduations. I'm not sure how the camera processes internally (I thought it was 10 bit). If you go straight to a 10 bit codec (like Cineform or Avid's DNxHD, both of which have 8 and 10 bit versions) and process everything in 16 bit you may be able to get around this.
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Old April 26th, 2007, 04:55 AM   #17
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Thank you, John.

The stepping is visible before post, especially when viewed on a full-HD monitor - and in the final edit. It is less noticeable in SD.

We did not try to mask the pixel(s) yet in post as this was a (successful)screener only, but we'll have to do it if we take it to festivals. So your tip about cinform is welcome as it will allow us to clean up the scene.
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Old April 26th, 2007, 05:06 PM   #18
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Quote:
Originally Posted by Claude Mangold View Post
Thank you, John.

The stepping is visible before post, especially when viewed on a full-HD monitor - and in the final edit. It is less noticeable in SD.

We did not try to mask the pixel(s) yet in post as this was a (successful)screener only, but we'll have to do it if we take it to festivals. So your tip about cinform is welcome as it will allow us to clean up the scene.
When you say a full HD monitor do you mean a broadcast CRT monitor or an LCD/ Plasma TV set? I only ask because LCD's and Plasma do their own internal processing to resize to their native resolution and they generally only do this in 8 bit. However, given your workflow it seems more likely these errors are being introduced by the camera's own processing.
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Old April 27th, 2007, 08:56 AM   #19
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Originally Posted by John Mitchell View Post
When you say a full HD monitor do you mean a broadcast CRT monitor or an LCD/ Plasma TV set? I only ask because LCD's and Plasma do their own internal processing to resize to their native resolution and they generally only do this in 8 bit. However, given your workflow it seems more likely these errors are being introduced by the camera's own processing.
It's a broadcast LCD monitor - Panasonic BT-LH1700WE (1280x768) hooked up via component to the cam.
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Old April 28th, 2007, 03:50 PM   #20
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Try turning the detail setting to "minimum", having it set to normal or above creates alot of noise in the HD modes.
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Old April 29th, 2007, 10:15 PM   #21
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Originally Posted by Claude Mangold View Post
It's a broadcast LCD monitor - Panasonic BT-LH1700WE (1280x768) hooked up via component to the cam.
Did you see the stepping live or off tape? If you saw it live the stepping is almost certainly due to the camera's processing, if you see it off tape then it could be conversions the signal is going through. If you saw it in the native .m2t file on a pc monitor displaying millions of colours, that would confirm that it is due to the cameras own internal processing.
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