Refractor Newbie & the Meade AR-5 OTA
Posted 24 October 2003 - 03:28 AM
The Celestron CG-5A took the lightweight 5” tube without complaints. Nice and stable, just how I like it. Since I have had clouds for about 4 weeks I had some other astrogoodies to try out as well.
I started out with the Meade 4000 26mm plossl. Hated it. I don’t know what the deal is but my Orion 25mm has a much nicer view. Then I tried the Meade 14mm UWA. Very stupid in my 1.25 Celestron crappy diagonal (although not as crappy as that plastic Meade diagonal thing they throw in with the scope!) OK, got it pointed at Mars but the finder was on the ground side at that direction (do most people rotate the tube, or just the diagonal like me?). I put in my old Orion 10mm plossl and was pleasantly surprised at how nice the view was. It snapped into focus and revealed some nice surface detail. I got lucky on the setup and the clock drives tracked perfectly.
My seeing was between clouds and the atmosphere was bouncing Mars around a bit, but it looked good! I tried the 10 in my Ultima Barlow and was rewarded with plenty of detail and a truly astonished feeling. Then I remembered my Celestron EP kit I had not tried yet. I grabbed the 9mm and found I like it much better than the 10mm Orion. Clear sharp views, what more could you want form a cheap plossl? I stuck it in the Barlow, but that was a little much for the conditions. So to compare Barlows I stuck the 15mm in. WOW nice. I couldn’t believe the detail I was getting out of this $275 OTA! So I tried the Celestron cheap barlow and found it not as bright and sharp as the Ulitma, but fully serviceable. I wouldn’t feel I was loosing much if this was the only Barlow I had.
Then I unscrewed the lens assembly off the Celestron Barlow, stuck it in the Ultima Barlow to make a longer Barlow. It increased the length about 1.5 inches. I stuck the 15mm in and wow! It worked! It increased the mag. of the Ultima and looked great. The 6mm Celestron was perfect for the conditions and I used it the most. Then out came the filters.
I had never used filters before and still prefer not to, but the red one really brought out the Mars features. It was like “black and red”. Very nice contrast. It seemed all the filters managed to bring out some extra detail. Notably the red, orange, yellow and blue in that order.
About the AR-5 in general: I was very impressed with the views. There was a shallow purple “fringe” around Mars but it didn’t detract from the experience. I was very impressed with the detail and contrast Mars showed with and without filters. I’m sure with a little tweaking of the focuser I’ll be able to improve on it as well.
The focuser sucks. It will do the job, but you know it’s bad when you just nudge the focuser up to center the planet. I want to replace the entire back plate/focuser assembly with the $249 offering from Burgess Optical, but that will have to wait $$.
The finder is nice! Easy to align and focus.
The dew shield seems a little short, but extending a few inches doesn’t seem like it would be too difficult.
It glides around nicely balanced, center mounted on the CG-5A. The mount has enough height to keep you off your hands and knees even at zenith.
All in all, a nice aperture f/9.3 refractor OTA offering surprisingly good views that can be routinely picked up for under $300. Fit and finish is a little lacking but definitely respectable. YMMV – IMHO
Posted 24 October 2003 - 04:39 AM
You might find at cetain attitudes a right angle finder is much easier to use. Especially at the zenith. I plan on replacing mine as soon as I get a working mount.
I'll have to take a look at Burgess's offerings for the backplate and focuser assembly.
Posted 24 October 2003 - 10:24 AM
Stacy, what tripod is that you have parked under the LXD55 EQ?
Posted 24 October 2003 - 10:42 AM
Posted 24 October 2003 - 12:28 PM
Problem is, they have no descriptions of what they fit.
Posted 24 October 2003 - 01:16 PM
I do not have the LXD-55 mount. I am just using my CG-5A (Which I understand can be easily modified with the LXD-55 motors and encoders!) The rings came with the scope and the plate came with the mount from Celestron. I want to get a longer plate though. The Atlas dovetails from Orion are very nice and inexpensive and fit the CG-5A perfectly. I think the 9” would be best for this scope? I have the 13” I got for my 8” newt and it works great!
I looked at the Starlites and they do indeed look awesome. However I want to use heavy 2” EP’s and maybe a camera so I’ll feel better replacing the whole focuser/backplate unit with the Burgess. I believe you just call Burgess direct and they will probably know exactly what you need. This link shows a satisfied customer. I got there from LXD55.com:
Yes, a right angle finder or two are on my list. I need one for the SCT as well. Any way to modify the straight ones?
Posted 24 October 2003 - 02:35 PM
Posted 25 October 2003 - 10:12 AM
I wanted to try and use the diagonal from my 90mm.
I think a longer dovetail would be much better with that size OTA.
Posted 25 October 2003 - 10:40 AM
Posted 25 October 2003 - 01:03 PM
Posted 25 October 2003 - 01:45 PM
Posted 25 October 2003 - 01:47 PM
Posted 25 October 2003 - 02:09 PM
Item # 7383 8" Atlas Dovetail Bar $14.95
Item # 7385 13" Atlas Dovetail Bar $18.95
They fit right on the CG-5 and other mounts I'm sure. Pictured is the 13" on my 8" Newt.
Posted 30 October 2003 - 03:46 AM
adding a PVC tube or something of the sort in the middle, and then putting the diagonal into the focuser.
That way for under 50$ you can have an 80mm right angle finder.
I'm thinking of making one of these myself (and if it ends up good enough I might even use it as a quick grab and go travelscope instead of my 10x50 binocs).
Posted 30 October 2003 - 03:39 PM
Posted 30 October 2003 - 05:38 PM
Posted 30 October 2003 - 05:42 PM
Posted 30 October 2003 - 08:28 PM
Posted 30 October 2003 - 08:54 PM
Hacksaw in hand … away I go.