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-   -   Indoor shots with a window in frame (mixed color temperatures) (https://www.dvinfo.net/forum/photon-management/96725-indoor-shots-window-frame-mixed-color-temperatures.html)

Reese Leysen June 17th, 2007 08:55 AM

Indoor shots with a window in frame (mixed color temperatures)
 
I'm struggling with indoor shots in our movie where there's a window in frame. How do I handle such situations where the white balance is set for indoor and I get ugly blue light from outside coming in? Thus far I'm doing tricky color correction to fix it, I'd like to hear if anyone here has better solutions, thanks!

Bill Hamell June 17th, 2007 09:44 AM

I just did this all day yesterday.
Our solution was to put ND on the windows and gel the lights with 1/2 CTB.
White balance and you are good to go. :-)

Bill

Reese Leysen June 17th, 2007 10:08 AM

Quote:

Originally Posted by Bill Hamell (Post 698029)
I just did this all day yesterday.
Our solution was to put ND on the windows and gel the lights with 1/2 CTB.
White balance and you are good to go. :-)

Bill

I'm sorry, I'm not much of a tech-head in the lighting/cinematography department yet.

How do you put an ND just on the window? You mean a neutral density filter, right?

And I don't think we can easily gel our worklights :) . (zero budget filmmaking...)

Seth Bloombaum June 17th, 2007 10:37 AM

Sorry about the zero budget.

1/2 or 3/4 CTB (color temperature blue) balances your tungsten lights to daylight. A 20x24" (about half a square meter?) sheet that might cover 1 to 4 lights, depending, costs about $7 US.

An alternative, that is usually more expensive because of how much you need, is to cover the windows with CTO (color temperature orange) gel. This stuff comes in sheets or rolls.

Then there is the brightness of the window light. As Bill suggested, ND (neuteral density) gray gell can be used on the windows to bring the intensity down. This can be combined in one gel with CTO.

Reese Leysen June 17th, 2007 11:36 AM

Ah alright, thanks a lot for the info!

Sean Skube June 17th, 2007 02:40 PM

Don't forget about color correcting to help resolve the issue as well.

Bill Davis June 17th, 2007 03:22 PM

Some companies, (GAM, I think, but possibly others) make gels that combine CTO with ND in a single sheet or roll.

As bright as it is here in Phoenix, I use it reasonably often to treat exterior windows in otherwise tungsten lit sets.

FWIW.

Reese Leysen June 17th, 2007 05:19 PM

I see, and would CTB gels work with my standard 500w halogen worklights?

Glenn Chan June 17th, 2007 05:37 PM

Quote:

Don't forget about color correcting to help resolve the issue as well.
Color correcting away mixed color temperatures isn't exactly easy. It's much better to get it right on set.

2- The standard method of gelling a light is to clip the gel to the barndoors using C-47s/clothespins (wooden). Lights emit A LOT of heat, so you should attach the gel vertically so the gel doesn't block the rising heat / you get ventilation.

http://efplighting.com/?Filters_and_gels

2b- You could somehow try adding barndoors to your light... but IMO you might as well find some deal on a professional light. They are more efficient, save you time, more controllable.

2c- As an alternative, you could build your own ghetto Kinoflo / "nano-light". There's video instructions on how to do this in Victor Milt's Light it Right DVD (see vasst.com). It gives you a soft light, which is generally more useful than hard light. You change color temp. by changing the bulbs.

2d- Or, you can just tape the gel onto a c-stand and shoot light through the gel. But this is not the greatest solution if you want to control the light.

Reese Leysen June 18th, 2007 02:50 AM

Excellent, thanks a lot guys. I think I'm gonna get a full CTB and some other CTB gels. I think I might need the full CTB because the halogen lights are really pretty warm.

Edit: any idea where I can get this fastest from Belgium?

Jimmy McKenzie June 18th, 2007 04:58 AM

Quote:

Originally Posted by Reese Leysen (Post 698193)
I see, and would CTB gels work with my standard 500w halogen worklights?

Gels on bigbox store worklights can turn to an icky goo real fast. You also mentioned that you are going to hunt for full CTB because your lights are so hot. It's the amount of colour temp. shift from 3200 kelvin (tungsten) you need, not the heat amount from the lamp.

Best of luck! Keep firefighting tools nearby when using those 500w outdoor only appliances indoors....

Reese Leysen June 18th, 2007 08:48 AM

Quote:

Originally Posted by Jimmy McKenzie (Post 698348)
Gels on bigbox store worklights can turn to an icky goo real fast. You also mentioned that you are going to hunt for full CTB because your lights are so hot. It's the amount of colour temp. shift from 3200 kelvin (tungsten) you need, not the heat amount from the lamp.

Best of luck! Keep firefighting tools nearby when using those 500w outdoor only appliances indoors....


I know :) . I meant that the lamps give a very warm light.

And thanks about the firefighting tip, I forgot about that and it's really important.

Sean Skube June 20th, 2007 03:28 PM

Oops. Should have been clearer. I meant CCing as an additional tool, not a means to fix it on it's own.

Don Donatello June 20th, 2007 06:14 PM

beware that full CTB is going to knock down your tungsten lights approx 2 stops !! will there still be enough light left to do what you want it to do ?

as others have suggested you can put 85ND, 85ND3, 85ND6, or 85ND9 on your windows ... you should be able to get the size you need from a local gaffer at a better price then retail stores ...

for zero budgets .. still call your local gaffer and see if they have thrown out any used CTB ( or other colors) gel recently that may be in their trash or he might just have a old roll with your size window he would sell for cheap ??...

for a pic of 1k light with blue gel look at the thread
http://www.dvinfo.net/conf/showthread.php?t=96749
post #4 .. 2nd photo ...

for ND on windows look at photo #6 where actors are in front of window ..

Reese Leysen June 21st, 2007 09:48 AM

Quote:

Originally Posted by Don Donatello (Post 699992)
beware that full CTB is going to knock down your tungsten lights approx 2 stops !! will there still be enough light left to do what you want it to do ?

as others have suggested you can put 85ND, 85ND3, 85ND6, or 85ND9 on your windows ... you should be able to get the size you need from a local gaffer at a better price then retail stores ...

for zero budgets .. still call your local gaffer and see if they have thrown out any used CTB ( or other colors) gel recently that may be in their trash or he might just have a old roll with your size window he would sell for cheap ??...

for a pic of 1k light with blue gel look at the thread
http://www.dvinfo.net/conf/showthread.php?t=96749
post #4 .. 2nd photo ...

for ND on windows look at photo #6 where actors are in front of window ..

Great info, thanks a lot man.

But I'm afraid our budget reaches no further than a bunch of CTB's for the lights. The 500watt worklights are pretty heavy, they can go down a few stops, I take it the CTB's (full blue or 1/2 blue at times) will diffuse the light a bit so there won't be as much extra need for diffusion as without the CTB's? (if so, that saves a stop or two)

Good advice on getting CTO sheets as well... I have no clue where to find a local gaffer but maybe I can dig up something.


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