Register to reply

Question about reflecting telescope design.

by mrspeedybob
Tags: telescope
Share this thread:
mrspeedybob
#1
Jul2-13, 05:10 AM
P: 705
Error in title. I meant refracting.

At every transition between air and glass it seems to me like there would be some reflection. Each photon it seems would have a certain probability of entering a lens and reflecting off of both of the lenses interior surfaces and then continuing on into the instrument. These reflected photons are not going to end up in the right place when contributing to the image.

Is this reflected light a significant design consideration for refracting telescopes? If so, what is done to minimize it's impact?
Phys.Org News Partner Science news on Phys.org
'Smart material' chin strap harvests energy from chewing
King Richard III died painfully on battlefield
Capturing ancient Maya sites from both a rat's and a 'bat's eye view'
Bobbywhy
#2
Jul2-13, 05:32 AM
PF Gold
P: 1,909
Telescope makers use non-reflective coatings to minimize this effect. Here's an overview with some good references for further study:
http://en.wikipedia.org/wiki/Anti-reflective_coating
chemisttree
#3
Jul2-13, 05:37 PM
Sci Advisor
HW Helper
PF Gold
chemisttree's Avatar
P: 3,724
Designers also use designs that minimize the number of glass/air interfaces. Oil spaced designs minimize those reflections.


Register to reply

Related Discussions
Reflecting telescope calculation Introductory Physics Homework 0
Reflecting Telescope or Refracting Telescope? Stargazing & Telescopes 16
Reflecting telescope principle and model please? Stargazing & Telescopes 3
Which is better, a refracting or a reflecting telescope? Stargazing & Telescopes 2
Shaving mirror for reflecting telescope... Stargazing & Telescopes 3