Best Ultra Lightweight 80-100mm Apo Refractor?
Posted 16 April 2012 - 06:15 PM
Posted 16 April 2012 - 07:18 PM
- Do you have budget?
- Does it have to be Triplet or is a doublet OK?
- 8lb including rings and mount plate etc?
- Is this for visual or AP?
Borg scopes are the lightest.
If you can find a used Borg 101ED, that would be one of the lightest 4" scope if not the lightest.
I own a Borg 125SD and even that scope (4.9") is just 7.8lb without the focuser.
Posted 16 April 2012 - 07:54 PM
As a former 150ED Borg owner, best and Borg, dont go in the same sentence, and a doublet is not to some an APO. Borg the Lightest absolutely....
under 8 probably the tmb 92SS that Astronomics sells....
unless you can find an AP Stoway and have lots and lots to spend......
Posted 16 April 2012 - 08:01 PM
Posted 16 April 2012 - 08:22 PM
Posted 16 April 2012 - 09:05 PM
Posted 17 April 2012 - 08:35 AM
Posted 17 April 2012 - 11:16 AM
Posted 17 April 2012 - 12:25 PM
Posted 17 April 2012 - 01:15 PM
6.1 LBS. OTA
TV-85 should suit your criteria, although I forget the tube weight. It's a great ultraportable scope.
8 LBS. with included 2"diagonal, 1.25 adapter, 20 mm Plossl eyepiece,
and tube clamp ring.
Posted 17 April 2012 - 03:12 PM
The TMB SS80CF (carbon fiber tube) is a light weight scope. The optics are outstanding.
The scope itself with a two speed 2" feathertouch focuser (as supplied) weighs 5# 4oz. (not the 4#3oz. listed), and that is without the objective lens cap.
With 2" Astro tech dielectric diagonal it is 6# 4oz.
With the supplied rings and short vixen style dovetail it it 8# 2oz.
Stick a 5mm BO/TMB planetary in the focuser and you are up to 8.5#.
Put a 17mm NaglerT4 in there and you are up 9.75#.
the TV85 with no diagonal, rdf or lens cap, but including clamshell weighs in at 6#14oz.
AT diagonal weighs 1#.
Both of these scopes with rings, diagonal, RDF and a 17mmT4 weigh ~10#.
Posted 17 April 2012 - 06:18 PM
LOMO 80/480 from Stellarvue sould do it.
Awesome scope, but it's not very light. I haven't weighed mine, but I'm sure it's got to be at least 8 lbs (with clamshell ring, but not including diagonal or EP).
Posted 17 April 2012 - 06:23 PM
Posted 18 April 2012 - 01:44 PM
Now sold under the name "Ekinox"
Got one of these second hand. The OTA only weighs 5.7lbs.
With CNC rings, 1.25" diagonal and typical EP your looking at 8.3lbs.
Very little CA as well for a f/6 ED doublet.
It is making my Megrez 90 look redundant.
None that I can detect in focus on Jupiter and very little on Venus.
Posted 18 April 2012 - 02:35 PM
I'm not doubting you, but that's really quite a feat for a 4" ED doublet as fast as f/6 to show such little chromatic aberration. I wonder what type of glass it uses? I don't know if the OP plans to use the scope for visual or imaging. My guess is that the scope you recommended may be adequate for visual, but probably not quite as pleasing for imaging use. Just my guess though, as I've never seen nor used the scope in question.
Posted 18 April 2012 - 03:18 PM
It uses FLP53.
The previous owner sold it on because it showed CA when imaging.
It's fine for me, I'm purely visual.
Posted 18 April 2012 - 03:37 PM
Posted 12 May 2013 - 03:13 AM