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March 3rd, 2005, 01:11 PM | #1 |
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Adjusting for White Balance Question
Curious to know what most use to adjust for White Balance.
Do most of you use a white piece of paper or white balance card http://www.bhphotovideo.com/bnh/cont...=300868&is=REG Warmcards http://www.warmcards.com/ or GretaMacbeth products http://usa.gretagmacbethstore.com/in...Menu%20USA.htm |
March 6th, 2005, 09:25 AM | #3 |
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I use a piece of white foamcore or 8 1/2" x11" warm card that I print myself.
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March 10th, 2005, 03:02 PM | #4 |
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I just got some warmcards in the mail. I've seen them used on sets and really liked their results. I'm testing them out tomorrow.
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March 10th, 2005, 03:30 PM | #5 |
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Thos warmcards look intresting, But I dont want to buy six for sixty-five dollars.
I just want one light or medium grade 3x4 Does anyone see where thats an option, or does anyone have a set they dont use all of? |
March 10th, 2005, 09:34 PM | #6 |
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Here is Walter Graff's response to this same question in DVXUser
"Here is a sort of non technical look at white blance. White balance is a relatively simple process. Your camera uses the green color channel as a reference for every thing it does. So red and blue are always compared to green and you get the correct colors of the rainbow. So when you hit the black balance on a camera you'll see that the viewfinder shows black and suddenly the black seems to change levels. What you are seeing is the following. The camera looks at green and then compares the red to green and the blue to green if the red and blue do not rest on the same plane as green then the camera quickly makes them identical. That is what the different shifts of black are in the viewfinder when you hit white balance. Its first the green channel, then the red and blue channels being compared to green and adjusted. White balance is similar but it uses the white peaks of the colors and makes the appropriate adjustments. So the idea is that if you aim the camera at something white it will reflect the color temperature of the light hitting the white surface. The camera sees where green is in that reflection and makes red and blue the same. And when its done you get a camera that sees white the way you do. Actually (you have an auto white balance in your head that makes adjustments on the fly). So the secret to a good white balance is to fill up your frame with at least 80% of something white. It could be a white sneaker (tennis shoe), white piece of paper, a white shirt, etc. And that white need only reflect the color temperature of the room you are in. If its a mixed color temperature you have to decide which color temperature you want to predominantly be represented in a shot. So if your room is all 3000k and you have a little window in the background with 4600k outdoor light, but WB for just the 3000k, you get correct color for the room and the window looks blue. This is ok. It IS blue outside and you will not be able to find a perfect balance at such a color temperature extreme. You don't need to. But say you are in a room with 4000k ceiling florescent's and you are going to supplement your lights with 3000k lights. You could gel lights but why bother. Simply adjust your white card so it get s a bit of both color temperatures and you will get a balance of the two and a good white balance. Use a monitor to see the results. If it looks to blue WB again and get more flouro and less incandescent. Too orange, get more incandescent and less flouro. If you remember from my lecture ( I gave everyone a swatch book), you can use gels to help crate subtle WB effects. Warms cards are a waste of money and you can do the effect better like this. If you have a Lee dealer you know, ask for a cinematographers swatch book. If not check the website. I think you can order one free. This swatch book contains about 50 4"x4" gel samples including color temp blue (CTB) and color temp orange (CTO). WIth these you can do the exact same thing as an $80 warm card. So remember I said that white balance was the comparison of red minus green and blue minus green till they were all in the same place? But what if I took apiece of 1/8th CTO from that swatch book and placed it in front of the camera so that when I aimed my camera at something white, the white had an extra amount of that orange gel? If I white balance the camera will subtract more orange giving me more cyan and that would make my picture cooler looking. And the opposite is true. If I took an 1/8 CTB and did the same, I would add blue giving me more amber and the picture would look warmer. Using 1/4 of either CTB and CTO gives me appropriately more of each color. That is what a warm card is. So don't waste your money on one of these when you can do the same trick to more of a degree with a pice of gel. These premade plastic white cards and warm cards are fine if you want to use them but they get old, fade, get dirty, etc so eventually you might not have such a white card. And white is everywhere so once again its free." http://www.dvxuser.com/V3/showthread.php?t=20201 |
March 11th, 2005, 08:02 AM | #8 |
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OK so how do I get my hands on one of these swatch books ?
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March 11th, 2005, 09:36 AM | #9 |
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<<<-- Originally posted by Samuel Birkan : OK so how do I get my hands on one of these swatch books ? -->>>
Here is a link for Lee Filters. These are the ones Walter gave us in the seminar. http://www.leefiltersusa.com/NewLigh...ewProdSWB.html |
March 11th, 2005, 09:38 AM | #10 |
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Wow, thanks Ray!
That's a great idea. I just ordered a swatchbook from the Barbizon store in Chicago. And it's free!! This will give me so much more control w/ white balance. Too bad I won't have them for today's shoot! Samuel, here is a link I found helpful for figuring out which swatchbook to get and who might sell them. http://shop.barbizon.com/docs/product/color.html
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March 11th, 2005, 12:30 PM | #11 |
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This may be the stupidest question ever but...
What exactly is the purpose of white balance? I've never really used it before, perhaps I should...
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March 11th, 2005, 12:57 PM | #12 |
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<<<-- Originally posted by Jan van den Hemel : This may be the stupidest question ever but...
What exactly is the purpose of white balance? I've never really used it before, perhaps I should... -->>> Jan read above where I copied Walter Graffs' comment and he explains it in detail. What camera are you shooting with Jan? |
March 11th, 2005, 01:00 PM | #13 |
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Thanks for the info guys, I called Barbizon in NY and they were out of stock so I called the Lee USA 800 number and ordered 1. Rosco at rosco.com also have an order form for swatches
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March 11th, 2005, 01:03 PM | #14 |
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Jan:
A good book for you to get a better unstanding of Lighting is called "Lighting" by John Jackman http://www.bhphotovideo.com/bnh/cont...=332733&is=REG |
March 11th, 2005, 01:13 PM | #15 |
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ideally, you want the swatch that is 4" x 4"
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