Extending something I wrote about in passing, is this discussion which beats that old Canon horse: “Canon L lenses use white because they absorb less heat from sunlight—a purely functional, not cosmetic consideration.”
Is this true?
The physics of white
I’ve heard this argument many times before from Canon and Canon L-lens addicts. After all this time, it still sounds like a pile of shit.
The rumor is that it was because they use fluorite as the low dispersion glass of their lenses—that sounds like half bullshit. Calcium fluorite is a crystal so it will be more susceptible to thermal shock. But the trick is to trust the astronomers, does this sound likely?
Besides, how many Canon lenses still use fluorite as their low-dispersion glass? If any do, it sounds a bit silly: ED/UD/SLD glass has improved to have better optical properties than fluorite.
The real physics of white
Why did Canon paint their lenses white? I think it’s because solar observatories and telescopes were painted white in order to keep the air inside at a steady temperature during the day.
(Whenever you think photographers are obsessive, just remember that for astronomers, they have to be obsessive.)
The way I figure it, I guess the Canon guys saw that and thought to themselves, “white = astronomer telescope1 = big magnification” and a marketing legend was born.
Personally, white (with alternating black for the focusing and zoom rings) screams cheapness on a 35mm SLR camera. I much prefer the black with a nice gold ring accent. 🙂
A favorite pasttime
One of my favorite things to do:
Someone: “I’m an astronomy major.”
Me: “Oh wow, that’s cool. I’m a Gemini, what are you?”
They love that shit, trust me. 😉