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Old January 26th, 2010, 05:34 PM   #1
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Worth while trying to correct colour cast?

OK this was not one of my best efforts!

The situation:
•An event organised at short notice and a late decision to have it recorded.
•Poor quality available light (fluorescent) only
•Canon HV-30 on P mode with W/B set at "fluorescent" (BIG mistake!)
•Recorded direct to Hard Drive on Philips DVDR3460H for basic editing then burning to DVD
•So no DV copy on tape - DVD copy or composite out are the available sources.
•Hard Drive recorder compression setting at "standard" (= about 2 hours on a DVD)

The recording has a horrible yellow(??) colour cast. Given that the only master copy is on MPEG-2, is it worthwhile trying to take it in to FCE on another codec to tweak the colour balance? If the image is going to fall apart with noisy multicolored grain I won't bother to try.
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Old January 26th, 2010, 06:00 PM   #2
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depends (as always)
you can make a MPEG2 dvd with a talking head in a 2hr mode, and not lose so much in the compression, or you can make a dvd where every pixel is moving in every frame, and it is only an "output" format at that point.

You said DVD, so it is SD right? when you decode just flat out decompress the whole thing, then you dont have any RE-encoding going on till you recompress to get it back to DVD.

If you only need a total everything color processing, myself i would shove it into Virtual Dub , set the processing which will be a single decode , filtering, and then output it uncompressed, shove it into the DVD creation program uncompressed to finish.

tweak the color itself down a bit instead of the usual Vivid color , and it is more likly to survive the process. a little low in color average color grain noise, and artifacts everywhere. Your biggest problem from what i read, will be the florescents original limited colors, and your quite opposite recording of them :-) there isnt likly to be a lot of spectrum. how do you do a yellow under florescent?

Did i mention that when you have it in virtual dub after the color correction, slap in some temporal filtering :-) that will clean up some of the noise, and help out on the re-compression as there will be less pixels moving.

that just leaves the Artifacting and all the now gone color bits, good deblocking decode, some color smoothing.

If a customer wanted YOU to fix thier Junkey yellow mightmare and only had a DVD , and they were willing to pay, would you do the job or turn down the money? I guess warning yourself that it might not look so great , isnt nessisary in this situation :-)
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Old January 27th, 2010, 10:30 AM   #3
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Thanks Marty. The amount of motion varies greatly from a static bagpiper to a group of dancers, though fortunately the camera was locked down at that point. It was Standard Def, and 4:3 at that because the footage was intended for computer monitors and data projection on 4:3ish screens. (It's a PITA to reset the projectors for 16:9, lots of our users wouldn't know how/wouldn't bother).

I was caught out because I normally have stage lighting in that venue and the tungsten WB works fine with it. I realised just before it started that the tungsten WB looked very odd through the LCD with just the fluorescent house lights so I took a chance on the other setting as there was nothing white handy to do a manual with. I might have been better with the auto setting.

At least the audio was OK as I guessed right with the mic placement :-)
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Old January 27th, 2010, 11:05 AM   #4
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ohhh, so you had a flor white balance , because of house lights, and onstage incan, that makes much more sence.
bet you wont do that again :-)
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Old January 27th, 2010, 11:49 AM   #5
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Quote:
ohhh, so you had a flor white balance , because of house lights, and onstage incan, that makes much more sence.
No tungsten at all. It became clear just before it started that this was going to run with just houselights.

Quote:
bet you wont do that again :-)
Correct.

Still can't figure why it turned out yellow though. Yucky green I might have expected.
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Old January 29th, 2010, 10:51 AM   #6
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Use it as an opportunity to upsell the client for some additional lighting next time. Explain to them how bad fluro lighting is and show them the before-correction results.

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