Mixing light temperatures

[Rick Wise]

Given the equipment you have, you do have a bit of a problem.

Step one: look at your location in the middle of the morning, and then again in the middle of the afternoon. Where is the sun? (You can also just figure this out using a compass.) What you want is the sun coming in the window, so that what you see outside is the shady side of whatever is out there — trees or buildings. If what’s outside is a vast field of grass, you are going to take another approach: shoot at dusk or dawn.

Your tiny tungsten units will be next to totally impotent in relation to the sunlight. A cheap solution: buy a couple of large, door-sized plastic mirrors at Wall Mart or Home Depot. Grab some of the sunlight coming into the window and bounce that into the second mirror which is placed so that you get some decent fill. Buy some plastic shower curtain at the same outlets. Hang the curtain so that it filters the bounced sunlight. You might want to go with two layers, each separated from the other by at least a foot.

An alternative method: bounce the first mirror into a 4 x 8 sheet of foamcore placed for best effect. Then you only need one mirror. But get the shower curtain anyway — the foamcore may be too hard. You want a very large, soft source of fill.

If the outside is dark enough, you could rig your shower curtain outside the window so that the camera does not see it, but the sun is softened. Again, 2 layers might be good. This method has the benefit of reducing the sunlight’s intensity, reducing the amount of light you need to add inside the room. I would still get the large mirror for the double bounce as above.

As for the tungsten units, you want to gel them with 1/2 CTB. Since you don’t know what gels you have, buy some. Use for accents on the background.

Rick Wise
director of photography
San Francisco Bay Area
and part-time instructor lighting and camera
grad school, SF Academy of Art University/Film and Video
https://www.RickWiseDP.com
https://www.linkedin.com/in/rwise
email: Rick@RickWiseDP.com

[John Sharaf]

Eric,

Simply put the daylight is blue (5600K) and the tungsten lights you have are yellow (3200). You can adjust their color by adding blue gel; full correction is known as CTB, alternatively there is less with 1/2, 1/4, etc. The problem is that adding blue gel to the tungsten lights cuts their output dramatically, more than half, where you need an enormous amount of light to balance the outside levels.

To balance these two levels you can use neutral density gel on the window (put outside to reduce reflections, and mount very carefully because it’s now part of the shot) or use “combination” neutral density and CTO (color correction from daylight to tungsten) then you need not change the color of the artificial lights. In your case this is probably the best course.

The real best solution is to use more powerful HMI lights which are daylight in color and 4x the efficiency of tungsten, such that a 1200w HMI equals the output of a 5000w tungsten and is already daylight corrected (without additional gels).

JS

[Eric Nicastro]

What should I white balance my camera from? Should I do it from inside the house against the window or shooting through the window with my white card outside the house?

[Richard Herd]

I place my white cards where the subject is.