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Thanks for the context, that's really interesting: big numbers, wow. Question: why not LED? Is there some quality of incandescent (I assume) bulbs which LEDs c

Thanks for the context, that's really interesting: big numbers, wow. Question: why not LED? Is there some quality of incandescent (I assume) bulbs which LEDs can't duplicate more cheaply? I guess so, but what would you say it is?

danielvf 3y ago
These lights date from the 60's, and were, and continue to be, the cheapest and most reliable possible way to throw boatloads of light at something. They are also flexible in that you can load them up with very narrow bulbs, as used here, or wide, or many choices in between. It's hard to overemphasize just how much the film industry values reliability over everything else. These things are stupidly reliable. There's probably a big case somewhere on a truck nearby with a bunch of replacement bulbs of different zooms, and that's about the only thing that can go wrong here. I've written the software stack for two different high-performance theatrical LEDs, and the hardware side is near rocket science to be ultra reliable and ultra performant. It's possible to get the same qualities of light out of LED's as from a tungsten bulb, but it's expensive and difficult, so most LED's lights are ether noticeably different, stupidly expensive, or both. On the other hand, the maxi brute here costs 1/10th as much, and has been battle tested by generations of roadies. Plus, the warm glow is nice.
user_7832 3y ago
> Question: why not LED? Is there some quality of incandescent (I assume) bulbs which LEDs can't duplicate more cheaply? I guess so, but what would you say it is? I'd suspect the coverage of the light spectrum (CRI or equivalent) also plays a role.
johncalvinyoung 3y ago
Spectrum/shape of the spectral efficiency curve. Sure, you can get a vague color temperature match out of LED, but it's HARD to get a curve out of LED that looks at all like sunlight or like tungsten incandescents. And even the really good ones are noticeably deficient in reds. I can totally believe that if they're attempting to simulate a sunrise there's nothing like massive incandescents.

danielvf 3y ago

These lights date from the 60's, and were, and continue to be, the cheapest and most reliable possible way to throw boatloads of light at something. They are also flexible in that you can load them up with very narrow bulbs, as used here, or wide, or many choices in between. It's hard to overemphasize just how much the film industry values reliability over everything else. These things are stupidly reliable. There's probably a big case somewhere on a truck nearby with a bunch of replacement bulbs of different zooms, and that's about the only thing that can go wrong here. I've written the software stack for two different high-performance theatrical LEDs, and the hardware side is near rocket science to be ultra reliable and ultra performant. It's possible to get the same qualities of light out of LED's as from a tungsten bulb, but it's expensive and difficult, so most LED's lights are ether noticeably different, stupidly expensive, or both. On the other hand, the maxi brute here costs 1/10th as much, and has been battle tested by generations of roadies. Plus, the warm glow is nice.

user_7832 3y ago

> Question: why not LED? Is there some quality of incandescent (I assume) bulbs which LEDs can't duplicate more cheaply? I guess so, but what would you say it is? I'd suspect the coverage of the light spectrum (CRI or equivalent) also plays a role.

johncalvinyoung 3y ago

Spectrum/shape of the spectral efficiency curve. Sure, you can get a vague color temperature match out of LED, but it's HARD to get a curve out of LED that looks at all like sunlight or like tungsten incandescents. And even the really good ones are noticeably deficient in reds. I can totally believe that if they're attempting to simulate a sunrise there's nothing like massive incandescents.