Day interior lighting: WB, CT by look

[Nathaly Pinheiro]

Hello!

When lighting day interiors, I understand we want to imitate skylight and direct sunlight through the windows.  

A book Im reading says: The skylight is cooler in color temperature than sunlight, around 6500K most of the day.  Direct sunlight vary during the day.

So I have seen many bts to try to list the combinations when the dp wants to achieve a certain look (early morning look, noon, late afternoon etc).. some listed below but Im still not sure about it because sometimes some of them do something different haha. 

Can anyone help me explaining first what are the main looks ? Second the common combinations of white balance, CT of fixtures to achieve them? 

 

For example:

1) Early morning look

WB 4500. 

Direct sun: fresnel 3200K 

HMI 5600K (soft)

 

2) Noon WB 5600K

Soft o direct are 5600K)

 

3) Late afternoon

WB 5600K

Fresnel 3200 (direct)

 

Golden hour 

WB 7000

Tungsten 

What would be the skylight in this case? 

[Stephen Sanchez]

Sunrise and sunset are technically the same. I say "technically" because scientifically they are the same process. In Florida though (where I live), sunsets are typically redder because clouds have formed during the day cycle and red light hits those clouds, and skylight hits those clouds and they glow pink and purple and the colors bounce down to the neighborhoods. During overcast sunsets, the clouds are yellow. So this is where you can take artistic license to differentiate if you'd like.

I understand why you're changing your WB, to keep from gelling your lights. It becomes easier when you don't have to do that anymore. Try to have color tunable fixtures, or half CTO and half CTB gels at least, to adjust beyond what the fixtures give.

You noted that some DPs do things different sometimes. A good DP and gaffer will take into account science of the light for the scene, along with art. Some may lean into art more than science, some may lean on science with little art. Because our work is for entertainment, or to sell brands, there is an inherent bias toward the treatment of the material, and so our work contains cheats and adjustments that would not normally appear in reality. So your DP did something he felt was appropriate for the material that diverted from science. A sunset for Transformers is different from a sunset for Tumble Leaf, or Pitch Black.

But also, keep in mind that some folks don't understand the difference between science and art lighting at all. So just because somebody does something, doesn't mean that is true for other workers. I think you're on a great track. Keep learning about the science and it will allow you to dissect other's setups more confidently.

Keep in mind though that observational learning means nothing without testing.

[David Mullen ASC]

You’d want the look of warm direct sun and cool soft skylight — and the sun gets warmer and warmer as it goes down, and also dimmer relative to the cold skylight.

There are many ways to get that effect so there’s no right or wrong way. You can use a tungsten lamp for the sun and a daylight lamp for the soft skylight and set the color temp of the camera halfway between but you can also tweak that further with gels. Certainly you could leave the tungsten sun ungelled and keep raising the camera’s color temperature setting to warm it up but then you’d have to keep gelling your skylight lighting bluer to compensate. Which mix of gels and settings you use just depends on the situation like the view out the window.