Lighting Interiors for Video

[Todd Terry]

What you are asking for is one of the things that cinematographers have to deal with all the time… well lit interiors where you can still see outside views at the same time.

Bascially it’s a choice among various methods, and sometimes a combination of them. Firstly, there’s simply using enough of the right lighting instruments to give you enough illumination indoors (usually that means HMI instruments), then there is darkening (and sometimes color-correcting) the windows with gel, screen, or both. And then there is the option to “fake it” in post by shooting exposures twice (one for interior, another for exterior), then compositing them in post.

This has been discussed very exhaustively here. I bet if you do a search in the lighting forum just using the keyword “windows” you’ll find tons of posts with lots of helpful tips for combatting this problem.

It’s not an easy one to fix (and usually not one for a novice cinematographer), but it certainly can be done.

T2

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Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Michael Asgian]

Thanks Todd for your answer… I’m sure it can be done with the right lights. I prefer to do it all in one, not doing in post because camera is moving on a jib or a slider.

I need some powerful lights I guess but I don’t know what lights should I look into? CFLs? Metal Halide bulbs? LED arrays? etc. I know lighting for photography. Should be the same in principle, with details that I will discover soon for sure, but I need a starting point for the lighting gear.

Looked over at B&H and those cinema lights are sold for small fortunes. Any other ways? I’m not affraid of DIY either.

[Todd Terry]

Barring doing any post voodoo or taking time to screen and/or gel windows (which can be time consuming)…

…if you ONLY want to do it with lighting instruments…

Then HMIs are the only real choice.

On a sunny day outside, nothing else is going to have anywhere near the output that you need. You are talking a fair bit of money though… definitely four figures per instrument.

They are also available for daily rental (usually anywhere from 200-400/day), if you have a vendor wherever you are.

Also keep in mind that you don’t want the interior as hot as the exterior. You don’t want windows totally blown out, but you don’t want the the same as inside either or it will look completely fake. Windows should be a stop or two hotter than the rest of the scene.

There are some new flavors of LED instruments (such as those from Aadyntech) that rival the output of smaller HMI heads, and also have the advantage of cool temps and very low power draws… but they are fairly pricey mid-to-high four-figure instruments as well… and not many rental places have them in inventory yet.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Michael Asgian]

The CFLs avenue is out of question then?

I have 2 bulbs each 150W, 5500K. I used them for some product shots. They are pretty bright…
I was wondering if having a few of those (like 10 or more) instead of HMIs could be an alternative?

[Todd Terry]

It would take about 40 150w CFLs (and I’m talking the really big actual watt flo tubes, not the “equivalent to 150w tungsten” tubes) to give you roughly the same output as a single 1200w HMI (remember that HMIs have about 5x the output per watt compared to tungsten).

And even one 1200w HMI wouldn’t have enough punch to battle the sun if you have a lot of windows or a big 10×30 room like you are talking about.

Turn on one of your CFLs in a room like that on a bright sunny day as a test. If you’re not looking at the lamp, you won’t even be able to tell that it’s on.

Sorry but that’s just not the right tool for the job. It’s trying to overhaul a V8 engine with a pair of tweezers.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Michael Asgian]

You are right! Unfortunately 🙂

Done some measuring with my lightmeter, It would take about 20-25 of those CFLs…
hard to manage on location… not to practical. I have to get in and out as fast as I can…

Back to HMI…

I saw these to our Chinese brothers…

https://www.aliexpress.com/item/wholesale-1000W-HMI-Fresnel-Light-Photography-lighting-Photography-Spotlight-Studio-spotlight-SP-1000/539932595.html

Are they worth considering? What’s the catch?

[Mark Suszko]

Listen to Todd, he is right.

HMI or “Heavy Monetary Investment” lights (grin) are the only tool for this. The JokerBug family of products is a popular choice and often used by TV news crews shooting in the same conditions you face.

You other choice is to replace your jib/slider with a motion-control rig that can do the same move with precision, then you just do each move twice with two exposures and do a blending mode comp in the editing timeline. Huge rolls of gel are available and they are re-usable, you’d have to apply them from the outside and hid the fact they are on the doorways and windows, but you’d regain the freedom to shoot the way you like. You’d have to factor in the extra set up time invested in gelling the outside views. This can be streamlined by stapling gels to wooden frames of standard dimensions for windows and doors. But then you’ll need a bigger vehicle to haul all the grip gear.

TANSTAAFL

[Michael Asgian]

Hey Mark, yeah. Got to the conclusion that Todd is right. However I’m open to find cheaper ways…

From what I understand reading and educating myself on this topic, “HMI” is a trademark… the bulbs are in fact Metal Halide. I’m looking up right now a few chinese knockoffs of Arris and the prices are about 8x lower than the originals.

How bad can be those?

[Todd Terry]

[Mark Suszko] “HMI or “Heavy Monetary Investment” lights…”

Hahaha… I’ve never heard it expressed like that, Mark. I will, however, freely steal that without your permission.

I too love Joker-Bugs. Unfortunately the 800w Joker is what, about six grand now? That makes them a bit more expensive (per watt) than other flavors of HMIs, but they make up for it in light weight and portability. In an environment like this though, I think it’d probably take a couple or three or more 800s. If I were shooting it myself with HMIs, I’d probably use a couple of 1200w heads, and maybe some smaller daylight instruments as well. As much as I love the 800 Jokers, I think they might be underpowered here.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Mark Suszko]

You were only a wiki away from the real definition:

Hydrargyrum medium-arc iodide, or HMI, is a Osram brand metal-halide gas discharge medium arc-length lamp manufactured for the film and entertainment industry. Hydrargyrum is Latin for mercury (Hg).
An HMI lamp uses mercury vapour mixed with metal halides in a quartz-glass envelope, with two tungsten electrodes of medium arc separation. Unlike traditional lighting units using incandescent light bulbs, HMIs need electrical ballasts, which are separated from the head via a header cable, to limit current and supply the proper voltage. The lamp operates by creating an electrical arc between two electrodes within the bulb that excites the pressurized mercury vapour and metal halides, and provides very high light output with greater efficacy than incandescent lighting units. The efficiency advantage is near fourfold, with approximately 85–108 lumens per watt of electricity. Unlike tungsten-halogen lamps where the halide gas is used to regenerate the filament and keep the evaporated tungsten from darkening, the mercury vapour and the metal halides in HMI lamps are what emit the light. The high CRI and color temperature are due to the specific lamp chemistries.