Click here if you are having trouble logging into the forums
Privacy Policy |
Please read our Terms
of Service | Signup and
Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User
Andy Taylor
twistin' by the pool
Reged: 09/24/08
Posts: 384
Loc: t=0 UK
|
|
Hi all...
I'm considering building a lightweight compact refractor for travelling.
At the moment I'm thinking of using a 100mm F4 objective and then further down near the focuser using a negative achromat to bring it to around F8...basically a full time barlow lens. What is the best placement?
Can anyone point out the pitfalls of doing this...?
--------------------
--------------------------------------------------
Equipment list of shame:
A strange heap of assorted junk that when thrown together and dragged out into the dark shows me the wonders of the universe...
And then dews up...
|
Owen
professor emeritus
Reged: 06/21/07
Posts: 510
|
|
Why not just fold an F8..?
Owen
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1390
Loc: Highland Park, CA
|
|
Quote:
Can anyone point out the pitfalls of doing this...?
CA out the wazoo?
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
Andy Taylor
twistin' by the pool
Reged: 09/24/08
Posts: 384
Loc: t=0 UK
|
|
Quote:
Why not just fold an F8..?
Owen
Yeah - why not make it...
TELESCOPIC!
DOH...! 
--------------------
--------------------------------------------------
Equipment list of shame:
A strange heap of assorted junk that when thrown together and dragged out into the dark shows me the wonders of the universe...
And then dews up...
|
Owen
professor emeritus
Reged: 06/21/07
Posts: 510
|
|
Theres no reason why a refractor needs a solid tube - using trusses could bring the poratbility you desire 
Owen
|
Gordon Rayner
scholastic sledgehammer
Reged: 03/24/07
Posts: 955
|
|
Have your seen the folded refractor in AMATEUR TELESCOPE MAKING, edited by Stephen F. Tonkin, from Springer?
I have two 10 5/8 inch airspaced doublets, in cells, f/10, and am considering making such an instrument( and in selling the other lens).
|
drexelpbp
sage
Reged: 01/21/08
Posts: 267
Loc: Phoenixville,PA
|
|
Hi Gordon
I have that book and I am also interested in making a similar instrument.
I was looking for other sources of design information on this kind of scope and also sources for objectives(I was thinking 8" f/10).
If you sell your objective how much are you looking for?
Thanks
Gary
--------------------
Orion 8" intelliscope
Celestron CF 8' SCT
Celestron 8SE
Celestron C80ED
Orion ST120
Orion ST80
Orion 120 f/8.3
Orion Skyview Pro Deluxe 90 f/11
Celesrton SP C102
Celestron SP 150N
Various Televue, Baader, Orion and other EPS
|
|
9 registered and 8 anonymous users are browsing this forum.
Moderator: Don W, Mike I. Jones
Print Thread
|
Forum Permissions
You cannot start new topics
You cannot reply to topics
HTML is disabled
UBBCode is enabled
|
Thread views: 349
|
|
|
|
|
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
