The Traveller was really the perfect size for a traveling 4" scope that would also work for quick take out. Is there a reason no one else has made a 4" scope, less than ten pounds and less than 20" long (outside of Borg)? It seems there would be a market, the backpacker created a lot of stir. It just seems someone should make one.
Why not a 4" travel refractor
Started by joemike, 09/16/2006 05:34AM
Posted 09/16/2006 05:34AM
Opening Post
Posted 09/16/2006 08:04AM
#1
>>>The Traveller was really the perfect size for a traveling 4" scope that would also work for quick take out. Is there a reason no one else has made a 4" scope, less than ten pounds and less than 20" long (outside of Borg)? It seems there would be a market, the backpacker created a lot of stir. It just seems someone should make one.
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Last year we did a 10 day car camping trip with a 4 inch F/6 Achromat as the largest scope. It performed quite nicely from the quite dark skies along the AZ-NM border. Obviously an APO would be better...
The problem I think is that a high quality 4 inch F/6 APO that is less than 20 inches long packed is not cheap... I figure for those willing to pay, someone much make something nice and compact in an 4inch F/6, SV or maybe TMB.
Currently I have taken a 20mm hit on the aperture and am enjoying an ED-80 as a travel refractor.
Jon
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Last year we did a 10 day car camping trip with a 4 inch F/6 Achromat as the largest scope. It performed quite nicely from the quite dark skies along the AZ-NM border. Obviously an APO would be better...
The problem I think is that a high quality 4 inch F/6 APO that is less than 20 inches long packed is not cheap... I figure for those willing to pay, someone much make something nice and compact in an 4inch F/6, SV or maybe TMB.
Currently I have taken a 20mm hit on the aperture and am enjoying an ED-80 as a travel refractor.
Jon
Posted 09/16/2006 12:11PM
#2
Joe,
If you can find a Stellarvue 102EDT on the used market, it might be just what you're looking for. Not many were made so they don't show up very often. It's a F6.2 triplet -- not quite true apo performance but much better than a typical doublet achro. Tube length is 21-1/2", but the focuser (JMI DX-1 two-speed) can be removed to get the length down to about 18".
Jim
If you can find a Stellarvue 102EDT on the used market, it might be just what you're looking for. Not many were made so they don't show up very often. It's a F6.2 triplet -- not quite true apo performance but much better than a typical doublet achro. Tube length is 21-1/2", but the focuser (JMI DX-1 two-speed) can be removed to get the length down to about 18".
Jim
Posted 09/18/2006 05:16PM
#3
The 110mm William Optics Zenithstar triplet comes close to your spec by the numbers. 110mm O.D., f/7, 9# OTA weight and a length of 22.8" with the dew shade retracted. I guess the question is whether the extra 2.8" is fatal to the "travel scope" designation?
- Jim
- Jim
Funding Member
