- Skill Level
- Time with Product
Feb 18, 2013
- User Notes:
8" f/7 Cave Astrola Model B Lightweight DeluxePros:
Superior optics and excellent mechanics. Still one-person portable.Cons:
Bulk and size are problems for some. Mount barely adequate.Comments:
I have owned a Cave Optical Astrola 8" f/7 Model B Lightweight Deluxe since 1987, and is one of only two telescopes I own that I can say I will never sell (having bought and sold literally dozens of telescopes in the past 35+ years). What makes this scope so special are its optics. In a word: FANTASTIC! Lunar and planetary views are simply magnificent provided that the scope is fully cooled and the seeing cooperates. Usable magnifications of up to 500X are possible on those rare nights of truly excellent seeing. Deep sky views are pretty much everything that they can be given 8 inches of aperture. The other telescope I will never sell is an equally superb 6" f/12 Astro-Physics Starfire triplet apochromat, and I can honestly say that my 8" Cave Model B gives views that are the equal of the much more expensive refractor in terms of the overall amount of planetary detail one can see, with only slightly less contrast and a bit more light scatter.
The overall mechanical quality of the telescope is excellent. The fiberglass tube is very stable and relatively lightweight. That fiberglass is a good insulator helps keep down tube currents caused by the body heat of the observer, which can sometimes be a problem with aluminum tube telescopes. The mirror mounts are of excellent quality and hold collimation very well. The 1.25" rack and pinion focuser is definitely "old school" in that it is certainly not "low profile," nor is it quite as smooth as many newer dual speed focusers. However, the focuser works well and is plenty robust. The 7X50mm finder is of very good optical quality, better than found on most scopes nowadays, and is held rigidly in extremely robust finder rings.
The biggest downside to this telescope is its mount. The "lightweight" mount sports 1" diameter stainless steel shafts and is only just adequate for a scope of this size. Damping time is on the order of 4 to 5 seconds, which can make focusing a bit tricky at high magnifications. The mount is simply not adequate if there is much of any wind at all, with the big tube of the telescope acting like a sail. I suspect that the 1.5" shaft mount that this OTA usually came with would be a better match for this scope, but would be significantly heavier, and even my "lightweight" mount is not really all that light. The need to use tools to disassemble and reassemble the mount is also not very convenient in the dar,The mount is, however, very smooth in its motions and tracks very well. For critical observing I actually use the 8" f/7 OTA on a Losmandy G11 mount, which is much better than the stock mounting and holds the scope steady even in moderate winds.
In my opinion, an 8" f/7 is perhaps the best all-around telescope. It is large enough to provide truly detailed planetary views (smaller apo refractors aren't even in the same league as this scope, IMHO) as well as provide very satisfying deep sky views. At f/7 most eyepiece designs work well, with images sharp to the edge of the field and plenty of depth of focus.
While big, bulky and a bit quirky, I really enjoy observing with my Cave Optical 8" Astrola. The scope has loads of charm, and always draws a crowd at star parties. What this scope really delivers, however, are the views. These scopes come up occasionally on the used market, and can be real bargains if you can find one in good condition.Sort by