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CTO and CTB??


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#1 Kyle Stueve

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Posted 27 April 2009 - 07:57 PM

Okay,

I am shooting a scene in a bedroom with the main source daylight with a 2k shooting through the window, and going to shoot 5500k preset on the hvx200 w/ redrock.
So if I want to have my arri Fresnel’s (wich are 3200k) match my preset, I would full CTO them??? Right? and for the 2k would I CTO that to match that as 5500k??

And the same at night, with the 2k my "moon" (shooting at 3200k then) I would full CTB it right?

thanks a lot
Kyle
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#2 Adrian Sierkowski

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Posted 27 April 2009 - 08:25 PM

CTO corrects Daylight to Tungsten, CTB corrects Tungsten to Daylight. To make a 3200K Fresnel match a daylight preset, you'd gel with CTO (full) and loose 2 stops of light from it. To make a window match the interior film lights (NOT the ones in your household lamp which are closest to 2900K) you'd use full CTO.

CTO; 5600K~>3200K
CTB; 3200K~>5600K

For more infor (and a free swatch book!) see http://www.leefilters.com/
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#3 Scott Bryant

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Posted 27 April 2009 - 10:03 PM

To make a 3200K Fresnel match a daylight preset, you'd gel with CTO (full) and loose 2 stops of light from it.


Wouldn't you gel CTB for this? or am I just not thinking of it the right way?
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#4 Chris Keth

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Posted 27 April 2009 - 10:33 PM

Wouldn't you gel CTB for this? or am I just not thinking of it the right way?


You're correct, Scott.

Tungsten Light+CTB=Daylight

Daylight+CTO=Tungsten Light
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#5 Adrian Sierkowski

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Posted 28 April 2009 - 04:36 AM

Woops, my mistake, brain-> hand malfunction.
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#6 Serge Teulon

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Posted 28 April 2009 - 05:09 AM

Kyle, why you shooting 5500K?
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#7 Kyle Stueve

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Posted 28 April 2009 - 08:20 PM

Kyle, why you shooting 5500K?


because most of the light in the room is day light mixed with a few arri's, I would rather do that then have to CTO the big window, when I can CTB the lamps im using. right?


kyle
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#8 Chris Keth

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Posted 28 April 2009 - 08:24 PM

because most of the light in the room is day light mixed with a few arri's, I would rather do that then have to CTO the big window, when I can CTB the lamps im using. right?


kyle


You can do that, but remember that full CTB will cut 1-2/3 stops from all of your lights that way. If you want the output of a 1K, you'll need a 5K scrimmed down a little bit once the CTB is on there. In most cases, it's easier and more efficient use of your resources to gel the windows orange.
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#9 Kyle Stueve

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Posted 28 April 2009 - 09:51 PM

You can do that, but remember that full CTB will cut 1-2/3 stops from all of your lights that way. If you want the output of a 1K, you'll need a 5K scrimmed down a little bit once the CTB is on there. In most cases, it's easier and more efficient use of your resources to gel the windows orange.


Yeah, I see what you are saying, we might be able to get away with 1/2 CTO, but having to gel the window would be better, I agree.

thanks for your reply
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#10 Serge Teulon

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Posted 29 April 2009 - 09:31 AM

As Chris has said....thanks Chris

Good luck Kyle
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#11 Chris Keth

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Posted 29 April 2009 - 07:48 PM

Yeah, I see what you are saying, we might be able to get away with 1/2 CTO, but having to gel the window would be better, I agree.

thanks for your reply


You can do partial correction if you want. It's pretty common (and a nice look) to have some orange-blue color contrast between sources like that.
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