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Old February 6th, 2004, 12:34 AM   #1
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Filter Question

If Im sooting under incandescent light and white balance my camera under incandescent light I should get a normal tintless image. My question is if I place a cooling filter on the lens but still blance for incandescent light will I get a bluish tint to the film? Or is it the other way around, balancing for daylight and placing a warming filter on the lens. Thanks for help
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Old February 6th, 2004, 01:41 AM   #2
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If your goal is to use a filter to alter the appearance of your imaging you would white-balance without the filter, then mount the filter to the lens.
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Old February 7th, 2004, 10:21 PM   #3
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What's your objective?

If you WB with your filter set to 3200K and shoot incandescent, you will end up with a properly balanced picture.

If you WB for 3200K and then flip to your 5600k filter, you will end up with a hideous, orange picture as you are adding the equivalent of an 85 filter which is used to balance daylight (blue) film to Tungsten, (orange).

If you WB with your filter set to 5600K and shoot daylight, you will end up with a properly balanced picture.

If you WB for 5600K and then flip to your 3200K filter, ( which is really no filter), you will end up with a very cold, blue picture.

What do you mean by a "cooling filter"? You may be able to acheive the same results by using different off-white, off-blue, cards during your initial color balance.

What effect are you going for?

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Old February 8th, 2004, 02:59 AM   #4
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Doesn't it work the other way around. I take photography pictures with daylight balance film and from expierence if I'm indoors at 3200k my pictures have a yellow/orange tint to it. I'm assuming this work in video as well. If I WB for 5500k but light the scene with 3200k lamps I will get a orange look to the video. But I trying to go for a blue look or cooler look for the shot. So I was wonderinf if I WB 3200k and light the scene 3200k and place a 5500k filter on the lens I would get a blue tone to the video? Is what I'm saying correct?
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Old February 8th, 2004, 05:33 PM   #5
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That's correct. If film is balanced for 5600 degrees Kelvin, (Daylight), and you shoot indoors with 3200 degree Kelvin light, (Tungsten), you will end up with an orange picture.

If film is balanced for Tungsten and you shoot in Daylight, you need to add an orange filter when shooting in Daylight to bring the balance back to Tungsten.

In the scenario you are talking about, if you add a blue filter, everything, and I mean everything, will be BLUE. If you are looking to give the scene a different feel by cooling the shot, I would either light it with some 1/2 blue and possibly by white balancing using some degree of off-tungsten shades.

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Old February 8th, 2004, 09:51 PM   #6
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Well I would normally use the blue gel on the lights but in the shot I'm planning to do, I need low light levels or no additionally lights at all. But the blue filter I'm plannig on using on the lens would bring the temp from 3200k to around 4200k. Will this be too blue? Where could I find this off white cards? Thanks for all your help so far.
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Old February 8th, 2004, 10:14 PM   #7
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I really feel that a blue filter will look totaly unnatural as everything will be tinged in blue.

The following website is a source for warm cards, the opposite of what you are trying to accomplish. Although it is not what you are looking for, it is something that you may want to use in the future.

http://www.warmcards.com/

I don't think they make cool cards, at least I haven't seen them.

What I have done to cool my image in the past is to white balance on a soft shade of pink. This could be fabric or something as simple as a piece of construction paper. You might want to experiment with different shades of pink/orange until you acheive your desired effect. This is relatively inexpensive and might just solve your problem without having to go through too much trouble.

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Old February 8th, 2004, 10:44 PM   #8
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If you want to cool down then white balance through some CTO gel (color temperature orange) You can get a free 3"x3" swatch book , that should have CTO, CTB and straw in small increments.

The straw and orange will cool things down while the color temp blue will warm things up. the gels come from 1/8 through double.
(1/8, 1/4, 1/2, 1 and 2)
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Old February 9th, 2004, 02:08 AM   #9
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I really like that idea of white balancing to a different color temp then buying all those expensive filters. So let me get this straight. If I'm in 3200k light and I take out lets say a CTO 1/4 that would make my camera color balance to about 2800k and would create a cooler image. I'm going to pick up some of these gels tomorrow from B&H and give it a try but thanks for all the help
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Old February 9th, 2004, 02:53 AM   #10
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No, no, you're still in the fog.

Remember, higher Kelvin temperature numbers producer bluer light (in your terms, "cooler"), lower Kelvin numbers produce redder ("warmer").

"White balancing" normalizes the camera to produce a visually white image from a light whose color temperature would not normally be white (reflected from a white card).

So, if you white balanced to 3200K light, then placed a CTO gel in front of the light, you would see a redder image but it would not produce an absolute 2800K color, since you had previously white balanced to 3200K.

At this point, it will be a more efficient and lasting learning experience for you to experiment for yourself.
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Old February 9th, 2004, 04:35 PM   #11
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Yeah I understand all this I have used filters before in the past in photography to change color temp. But film is mostly balanced to daylight temp and to achieve a bluer or cooler color to the film I would first measure the color of the light with my meter and if its lets say 8000k then I wouldn't need to do anything.

But in video you can white balance any scene and match the color correctly. In my case I'm indoors and the color temp is at 3200k. I would do what Brain had said and balance the camera through the CTO 1/4 which would balance my camera to around 2800k. Since my camera is at a lower temp then the light source I should get a bluer image.

I know in photography it works like this if your light source is a higher temp then what your film is blanced to then your are going to get a bluer image. If your light source is a lower temp than what your film is balanced to then then you will get a image with an organe tint to it.

The reason behind my questions and clarifaction is that I had some nice results with film in changing the color temp of the image in the past. I hope to achieve all this with video.
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Old February 9th, 2004, 05:33 PM   #12
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I think I'm getting where you are going, Anthony. If I may, it would probably help avoid some of the misunderstandings in this thread if you worked on your postings a bit from a grammatical standpoint by including more punctuation, that sort of thing. I understand that the Internet has encouraged a certain casualness in writing style but with these sort of technically complicated ideas, I think it helps get one's points across if the post is clearly written.

When you say you are holding a 1/4 CTO in front of the lens (that's what I believe you meant by "take out"), you are indeed creating a color temperature of around 2800 degrees kelvin in front of the camera (3200 plus the 1/4 CTO). Keep in mind that household incandescent fixtures usually output closer to 2900 degrees and the 1/4 CTO would drop this 300 degrees more. White balancing through this gel and then shooting without it would give a cooler/bluer cast to the image as you indicated.

Coming from a film background, the white balance flexibility is a great new tool and you are heading on the right track. Be aware that you also have plenty of opportunities in post to shift the color as well.

An extreme white balance (such as setting the WB through a full CTB to get a very warm cast) may have the side effect of adding noise as the gain in the individual channel is pumped up. In this instance, the use of a color filter or post-tinting may be preferable.

Good luck and happy experimenting!
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Old February 9th, 2004, 10:13 PM   #13
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Thank you and I apologize for my grammar but I'm far from 1300+ post but I will remember next time.

You hit the nail on the head for what I was going for and I got some gels today and will give it a try and see what type of results I get. I hope that it is close to what used to get on film.
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