Image of the day

Captured by
Mark Eby

IC410 Tadpole Nebula

My Account

New to Astromart?

Register an account...

Need Help?

Binocular tricks

Started by gnowell, 04/05/2009 01:34PM
Posted 04/05/2009 01:34PM Opening Post
I was reading about the Steiner Predator 10x42 binoculars. The text said something along the lines that the coatings were optimized for red transmission and against blue, the theory being that reds and browns are best for detecting game at dusk.

It seems to me though that we don't use much red in visual astronomy and that one could rephrase the Steiner text as saying that these binoculars are optimized for anti-astronomy.

My question is whether these sorts of "optimizations" in fact make a difference? And I guess as a more subtle point: how would you know what a particular binocular company is emphasizing in its design? Most of the sales blurbs just say maximum light transmission. It may not be the case that good birding or game binoculars are optimized for astronomy.

regards
Greg N

"Scope will get you through times of no money better than money will get you through times of no scope." --Freewheelin' Franklin
Posted 04/05/2009 02:06PM #1
I think most optics are optimized for maximum transmission across the visual wavelengths. Indeed the bragging about new models often includes "better light transmission," although all the high end binoculars are already quite good.

I view unusual coating choices as mainly marketing tools to differentiate them from the rest of the folks. The extreme example are the "ruby red" coatings.

Actually, I am not sure that better transmission in the red is "anti-astronomy," although I'd consider reduced transmission a bad idea. Many nebulae emit in the red (H-alpha).

Clear skies, Alan