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Orion's Apex 102mm Maksutov-Cassegrain

Posted by Blair Slayton   04/05/2005 07:00AM

Orion's Apex 102mm  Maksutov-Cassegrain
Orion’s Apex 102mm: A Quick Look

I guess I’m a casual observer, even though I’m out looking whenever the weather allows, as I’m not interested in trying to interpret faint fuzzies but prefer the bigger and brighter Messier and NGC objects like Open Clusters. Also, I like colorful double stars like Izar and Almach (and of course Albireo).

I also prefer a light weight portable setup even though I do most of my observing in my somewhat light polluted backyard (streetlights) in Greensboro, NC. I do not need GOTO as I know my way around the sky pretty well and my growing list of favorite objects are easy to find; many are noticeable in my Correct image, right angle 9X50mm viewfinder (CIRA). Also, I do not need a heavy, equatorial mount as my seeing seldom allows powers above 100X except on the Moon.

I’ve tried many scopes over the past two years and they were either too long or too heavy or both. Recently I bought Orion’s Apex 102mm Maksutov-Cassegrain (Mak) to use on my Orion’s AZ-3 that I bought a while back and after some use I feel this is the setup for me.

What I like:
1. The focuser is smooth and much easier to use to come to focus at high powers out of the box than Orion’s refractor rack and pinion focusers that usually require some adjusting before they get close to the smoothness of this Mak’s focuser.

2. No Chromatic Abberation.

3. 1300mm of focal length in such a short and light weight tube (about 5 pounds). I’ve found that most objects I like to look at are smaller than 1 degree in size and want powers from 50X to 100X. This long focal length allows the use of longer focal eyepieces for the powers I use most which helps to keep my eye from having to hug the eyepiece or to use a heavy and cumbersome barlow. A 13mm eyepiece gives 100X which is the usual maximum power my seeing allows.

4. Price.

What I do not like:

1. Cool down time. Most of the time this is not a problem as I usually put it outside at least an hour before viewing but could be a problem for quick looks when the weather suddenly clears.

This scope ($279 with a 25mm eyepiece, 6X26 viewfinder and 45 degree correct-image diagonal) could be a consideration for those looking at Stellarvue’s 80/9D ($399 with no eyepieces or diagonal) or Orion’s ED80 ($499 with no eyepieces or diagonal or viewfinder). At worst, this scope is equal to a 97mm obstruction free scope so it gives more aperature for the money than the mentioned scopes.

With this scope these accessories are working well:

* Orion’s 32mm Highlight Plossl (which gives about 1 degree field of view).

* Orion’s Explorer II Kellners; 25, 20, 17 and 13mm.

* Apogee’s 22 to 7.4mm zoom.

* Vixen standard 90 degree 1.25 inch diagonal.

* Orion’s 9X50mm CIRA viewfinder.

I bought the 1/4"-20 adapter for the AZ-3 and it works well with this scope except I suggest putting it on the scope first then on the mount so you can use a philips head screwdriver to tighten down the thumbwhell to the scopes tripod adapter as I could never tighten it well enough by hand.

Blair Slayton
5 April 2005

Click here for more about this subject. -Ed.