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Old August 25th, 2009, 05:34 PM   #1
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color correction - black level

all suits on this picture are black, but on video the men lapels and the child suite and socks look brown! how to correct it? see attached picture
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color correction - black level-colorcorrection.jpg  
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Old August 25th, 2009, 07:44 PM   #2
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the lapels look like they were satin material (common on tuxes) and they appear to be reflecting some warm light from overhead lights.
Chances are you can't fix that. I'd bet that's what the lapels looked like in realtime.
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Old August 25th, 2009, 07:59 PM   #3
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nope; all was black for human eyes;
child socks were rich black - that's for sure; so let it be a challenge to everybody - use attached picture and come with coordinates to make all look black - is it possible???;

not to mention that bridesmaids dressess were teal and on the video they are blue; to my surprise that EX1 couldn't handle teal!!! -beware.
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Old August 25th, 2009, 08:38 PM   #4
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If your 100% sure that all the blacks were the same, then it's probably a matter of the Sun bouncing off of the material differently..I suspect the child's suit isn't the same material as the men....
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Old August 25th, 2009, 08:56 PM   #5
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Quote:
Originally Posted by Peter Manojlovic View Post
If your 100% sure that all the blacks were the same, then it's probably a matter of the Sun bouncing off of the material differently..I suspect the child's suit isn't the same material as the men....
Polyester, nylon and other synthetic materials are more prone to this. It's a bit like the "color" in peacock feathers. The color is created by the feather's physical structure which "splits" the light into the colors that you see. It is somewhat analogous to what happens in prism. The prism isn't the colors that you see; it just "splits" the light into the different colors.
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Old August 25th, 2009, 09:13 PM   #6
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Jim,
how to explain it to Bride and Groom....;-) they don't care - black is black for them,
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Old August 25th, 2009, 09:20 PM   #7
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Peter,
I am sure those (child suit and groomsmen siuts) were not exactly the same if we measure them very pecisely; but for untrained eyes it was black.
take a look at picture nr2; here we have white balanced white dress, brownish black suit and teal dress which look like blue (we even have green clothhanger) - perfect combination.
My piont is that such a good camera like EX1 can't handle it! and there is big problem to correct it in post.
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Old August 25th, 2009, 09:34 PM   #8
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I know several people who use the EX-1. My impression regarding color accuracy is very good with it. Are you using the default camera settings? You can change profiles in the camera which is very useful to someone who knows what they are doing. If not, it can have some pretty stange effects - - - such as "shifting teal."
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Old August 25th, 2009, 09:43 PM   #9
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camera was not using any preset gamma; default setting; I couldn't predict teal dresses; but I was surprised to find out problem with black!
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Old August 25th, 2009, 09:51 PM   #10
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You might ask your question in the EX-1 thread. You might be able to get more specific input from EX-1 owners in that section of the forum.
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Old August 25th, 2009, 09:54 PM   #11
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yes, I pointed them here already;

but back to original question - do you know how to color correct the problem in Vegas - anyone???
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Old August 25th, 2009, 10:02 PM   #12
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Magic Bullet Looks can do some amazing things. Red Giant Software: Magic Bullet Looks 1.2

It's $400 but you can download their trial version and see what you think.
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Old August 25th, 2009, 10:11 PM   #13
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yes, I am using it for years; with proper graphic card it could work in real time
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Old August 25th, 2009, 10:16 PM   #14
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you don't correct it. Black is not always black and anyone that doesn't understand that is....

Light strikes different material diffferently and will make black, white and all colors look different, from 1 angle to another and that's the way it is. There is nothing you nor any client can do about it UNLESS you have a 100% controlled enviornment which weddings of course aren't.

Black is not always black and you can't fix what is not broken.
I'll bet the client won't notice unless you point it out to them. Hell I hardly noticed.

As for the camera not handling a certain color well, I know a number of folks that use the EX1 and they haven't had any problem with any color that they've ever mentioned so it could be a particular setting in your camera but it would be best asked in the EX1 forum.
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Old August 25th, 2009, 10:47 PM   #15
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If I'm correct, what we're seeing here is a phenomenon known as infrared contamination. It is known to happen with the EX1/EX3 along with other cameras like the RED-One. One of the design parameters for all our digital cameras is (IIRC) a high-pass IR filter and at what wavelength they choose can determine the amount of IR contamination that can appear. The effect is most pronounced under hot lights.

For the EX1 and EX3, many users find that a B+W 486 UV/IR Cut filter eliminates just enough IR to keep blacks looking black.

Unfortunately, I don't think there's much that can be done in post to correct for IR.

There have been several great discussions about IR contamination over in the EX1/EX3 forum.

-brooks
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