Los Angeles will be replacing its yellow streetlights with new, blue-tinted LEDs, which will dramatically change how the city appears on camera.

kleinbl00:

Trust Gizmodo to not really get it.

Here's the spectrum of the sun.

Here's the spectrum of a low-pressure sodium lamp.

Here's the spectrum of a daylight-balanced LED.

http://www.almadenobservatory.net/RobsObservatory/filters/ty...

Note how we're used to "spectrum with yellow" while streetlights give you "yellow and nothing else." The new LEDs give you "lots of blue with other things" (fun fact: every white LED you've ever seen is a blue LED with phosphors that "re-emit" the blue light as every color but blue). Sodium arc lamps were chosen, in no small part, because they have such a narrow bandwidth - which means you can filter them out for astronomy. We lost all practical usage of the Mt. Wilson Observatory through light pollution; Palomar requires San Diego to have even uglier, nastier bandwidth lights so that they can still use it.

So what we're talking about here, really, is a horrific yellow cast that exists primarily so that you can still sort of see the night sky with the right filters on. Having grown up elsewhere, the old LA streetlights are something terrible. In addition to the yellow light, they've got grimy gray-green filters on them that make light the color of morning-after beer piss. And yeah, I guess it's nifty for noir, but chocolate syrup made great blood for black'n'white, too.

'cuz that's what we're talking about - narrow-spectrum monopolar light being replaced with full-spectrum light. Is something lost? Gonna go ahead and say "no." You want that ugly yellow light? Shoot two cameras, one with a bandpass filter on it and the other without. Composite in post. Get whatever mix you want.

I've been photographing cities at night for twenty years now. Every effect you've ever wanted? I've gotten. The yellow shit sodium that they bemoan so much? Least attractive, least interesting lighting effect there is. Every cinematographer I know goes gaga over Kinos because they love that heinous green. Metal halides - what most everyone else is used to - are a beautiful bluish color. And we won't even get into the fact that you don't hear the lights anymore, or the fact that they're running on 15W instead of 400.

Yeah, you can point at one movie and go "loss!" but the fact of the matter is, when Ridley Scott shot the 2nd street tunnel for Blade Runner, they color timed it to look normal.

That's what most of us do.


posted 3732 days ago