Question to all you optics gurus out there

[PercyShelley]

Why is it that astronomers probe the deepest heavens with reflecting telescopes, and we aim our rifles with heavy, expensive refracting models like a bunch of suckers? And don't tell me "it's because reflecting telescopes invert the image," not all of them do. Is it a scaling issue? The pervasive design conservatism of the firearms industry? What's the deal?

 

[Dr. Tad Hussein Winslow]

I'm not really a guru, but...

we aim our rifles with heavy, expensive refracting models like a bunch of suckers?

I don't - I use these two reflectors for range spotting:

http://www.opticsplanet.net/celestron-c90-mak-spotting-scope.html

http://www.opticsplanet.net/celestron-c130mm-mak-spotting-scope.html

But of course, all riflescopes are refractors. As I understand things, I believe the answer to your question is - durability vs. fragility. Refractors take a bangin and keep on refracting. But reflectors can get their collimation and whatnot all outta whack by being dropped. Then you don't know until you miss the big buck and ruin your hunt. There may also be something about the difficulty of putting an adjustable reticle into a reflector - not sure.

 

[boilingleadbath]

The reflector element is lighter, right?
Shouldn't this improve their drop resistance?
(Unless they aren't designed to be drop resistant, but instead simply light weight. But that's a design issue, not a inherent feature.)

You generally get less light transmission off of a mirror than you do through a refractors. Plus, unless you use some sort of fancy angled aspherical mirror, you have a big fat obstruction in your optical system.

 

[PercyShelley]

Thanks, PremiumSauces. I had seen those reflector spotting scopes. Is yours noticeably lighter than a roughly equivalent refracting model?

Boilingleadbath; I don't know the numbers. Is the reflectivity of commercially available mirror finishes actually that much lower than the transmissivity of commercially availible glass? I'm curious too as to why the odd geometry of off-axis designs would be a problem. It's not like lenses are the simplest shapes to grind, and reflectors are easily foucault testable, which ought to speed prototyping.

 

[rkba_net]

Durability, simplicity, size and the lack of a need for HIGH (say 30X+) magnification...