Jump to content


Photo

Microscopic Telescope

  • Please log in to reply
8 replies to this topic

#1 Charlie Hein

Charlie Hein

    Voyager 1

  • *****
  • Administrators
  • Posts: 12308
  • Joined: 02 Nov 2003
  • Loc: 26.06.08N, +80.23.08W

Posted 05 April 2014 - 02:18 PM

Microscopic Telescope

By Josef Vnucko

#2 Bill Steen

Bill Steen

    Explorer 1

  • -----
  • Posts: 99
  • Joined: 15 Dec 2012
  • Loc: Broken Arrow, Oklahoma

Posted 06 April 2014 - 01:37 PM

Interesting concept, thanks for sharing. As with the focal point catadioptric telescopes many major suppliers make, having the lenses in exactly the right spot is going to be essential, as you pointed out. I am going to have to think about this one for a while, but I can say I certainly enjoyed reading about what you are doing! I consider your article mind expanding. Bill Steen

#3 Michael Miles

Michael Miles

    Apollo

  • -----
  • Posts: 1014
  • Joined: 11 Feb 2005

Posted 07 April 2014 - 02:05 PM

Isn't this type of telescope called a relay telescope?

http://www.atm-works...m/dilworth.html
http://en.wikipedia....wiki/Relay_lens

Michael

#4 Meep_Esq

Meep_Esq

    Explorer 1

  • -----
  • Posts: 74
  • Joined: 02 Jan 2007
  • Loc: Dunedin, New Zealand

Posted 08 April 2014 - 02:20 AM

Indeed. I think H. E. Dall in ATM book 2 (going back a-ways now :-) ) wrote about them and I believed he used 2 achromats arranged like a plossl (or symmetric eyepiece) for the relay lens. Although, I don't think Dall's point was as a amplifier as Josef writes about, but primarily to shrink the size of the 2ndary, and provide a decent amount of focus. It's a wrinkle that could probable see more use.

#5 MikeF

MikeF

    Lift Off

  • -----
  • Posts: 7
  • Joined: 03 Jun 2008
  • Loc: Bohol, Philippines

Posted 09 April 2014 - 06:59 AM

I been thinking about doing this for a long time, wondering what type of oil or solution you could use use between the symmetric relay lens to get rid of the two extra reflective surfaces? What type of lens to correct a spherical mirror - spherical aberration, that would negate the primary's collimanation. Very little has been written about telescope systems that uses lenses to correct and refocus the mirror past the first focal point. It has many advantages that have not been researched!

Michael Fidler
------------------
Jagna, Bohol, Philippines. (09.65N)
50cm f5.35 Newtonian
40cm f5.25 EQ Newtonian
31.5cm f8 Dobsonion
20cm f6.7 EQ Newtonian
25x100 Celestron Skymaster Binoculars

#6 MikeF

MikeF

    Lift Off

  • -----
  • Posts: 7
  • Joined: 03 Jun 2008
  • Loc: Bohol, Philippines

Posted 11 April 2014 - 03:37 AM

Here is an example, the old erecting system in antique folding spy glass and modify this way. Image F1 then achromatic relay lens at its FL produce parallel rays. Sub aperture corrector for coma, spherical aberration and flat field, in between and the 2nd achromatic relay lens to bring it to F2. What would be much nicer is a triplet that could do all three, but that would take some major optical design and special glass (rare earth). This is similar to the modern zoom spotting scope in basic design. The biggest problem is getting the alignment on the secondary mirror which is the downfall of cheap short FL Jones-Bird type telescopes.

Mike

------------------
Jagna, Bohol, Philippines. (09.65N)
50cm f5.35 Newtonian
40cm f5.25 EQ Newtonian
31.5cm f8 Dobsonion
20cm f6.7 EQ Newtonian
25x100 Celestron Skymaster Binoculars
Canon EOS Rebel T3i DSLR
:roflmao:

#7 MikeF

MikeF

    Lift Off

  • -----
  • Posts: 7
  • Joined: 03 Jun 2008
  • Loc: Bohol, Philippines

Posted 11 April 2014 - 03:47 AM

Erect

#8 MikeF

MikeF

    Lift Off

  • -----
  • Posts: 7
  • Joined: 03 Jun 2008
  • Loc: Bohol, Philippines

Posted 11 April 2014 - 03:53 AM

Correct

Attached Files



#9 Basard

Basard

    Sputnik

  • -----
  • Posts: 42
  • Joined: 23 Dec 2009

Posted 13 April 2014 - 07:10 PM

in a PERFECT world, each mirror would have a perfect curve or perfect flatness... robots will rule at that point.... you can make a telescope with a 100nm primary and a 1um secondary, as long as everything is perfect :p

i was just having this discussion of 'perfection' and 'infinity' with my girlfriend, thought i'd chime in with my new found 'wisdom'...

cool setup though!!






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics