Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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I just finished unboxing and assembling the mount...it only took about 15 mins.
FIRST IMPRESSION: This is a substantial mount!
The CG-5 is PETITE...downright DAINTY!
I can pick up the CG-5 EQ head in one hand and hardly notice the weight. On the CGEM, it's more of 'both hands and cradled in your arms'.
The CGEM is NOT a "grab 'n go" mount!
Yes, I can carry the mount and tripod, assembled but w/out counterweights, out of the garage to the driveway without TOO much strain...but, if you have serious back problems or are not "in shape", you're gonna' want wheelie-bars or a scope-buggy (you may want them just for convenience!).
Be advised, the mount alone comes with ONE (1) 17lb. counterweight. If you buy the mount WITH the C-9.25, it comes with a 17 lb. and an 11 lb. If you get the C-11, it comes with TWO (2) 17-pounders.
That is optimistic!
With my Carbon Fiber SN-10, I needed 50 lbs. (!) to balance it properly! And that OTA only weighs 30 lbs. - even with heavy duty focuser, finder, dew heaters/controllers and an eyepiece!
Yes, the height of the mounting rings and the additional mass of the longer tube add to the total weight needed to balance...but - just FYI.
The hand controller is identical to the one supplied with the CG-5.
The power cord has a nice feature that my CG-5 did not have - a 'lock' that threads onto a ring (around the
power input on the EQ head) and prevents the power cord from accidentally coming loose or pulling out.
I'm about to read the new alignment procedures and power the thing up.
More to come....
Mike Harvey
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zjc26138
Postmaster
Reged: 02/24/05
Posts: 5245
Loc: Mingo Junction, Ohio and Morga...
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Pics? Sounds like a great mount Mike! 
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Custom AR5
Stellarvue 80/9D
Bosma Goto Mount
Clear, dark skies everywhere,
-Zachary
Edited by zjc26138 (12/16/08 06:35 PM)
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Yedgy
sage
Reged: 07/22/08
Posts: 457
Loc: Phoenix, AZ, USA
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Pics please!  And please describe the sounds it makes slewing & tracking!
Thanks, and congrats on your new toy!
Tony
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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BobH
super member
Reged: 01/03/08
Posts: 143
Loc: PA
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Mike,
I'm as excited as you are  .
Looking forward to the pictures and "review."
Bob
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"Wise men learn more from fools than fools from the wise." - Cato the Elder
Meade 8" LX200 GPS
ETX 125 PE
Tasco 50mm x 600mm
StellarVue 115ST on MiniTower
Orion Astroview 100
Celestron 8x42 Outland LX
'03 Harley FXDL (oops, wrong forum)
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rodney
Vendor - Explora Dome
Reged: 03/08/05
Posts: 801
Loc: Asbury, NJ
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Mike,
Yes pics. And if you could get a clear set of pics of the tripod mounting surface that would be supreme. Agreed, lets us know if it is quieter than the AS-GT mount.
I'm not jealous, seriously, right!
Clear skies,
--------------------
My Explora Dome construction is here:
www.exploradome.us
Rodney
Meade 10 SCT
AT 8/F4 imaging scope
13 Truss
C8-NGT
Orion 80mm/F11
Canon 300D
Canon XSi
Two AS-GT mounts
Extremely happy Explora Dome home observatory owner
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Doug76
Postmaster
Reged: 12/05/07
Posts: 5539
Loc: SE Louisiana, future Texan
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I've seen pics. I'm interested in that, but more in how loud is it, and what does it sound like?
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kaaikop
scholastic sledgehammer
Reged: 07/13/08
Posts: 766
Loc: North of the Montreal nebula
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Yeah, no pics, no mount!
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Benoit, RASC Montreal
-C9.25 on EQ6 Pro - C6/ED80 on Portamount
-TV Plossls, Radians, Nags, Pans, UO Orthos.
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Jim7728
Postmaster
Reged: 04/10/05
Posts: 5063
Loc: Stoop Landing Observatory, NYC
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We all know what the CGEM looks like  , now take your time and report back here tomorrow with a 500 word in depth report
...with pictures. 
BTW
Thanks Mike, for your initial impressions of the new mount. 
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Jim
Genesis SDF-f/5.4 FS-102-f/8
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tboss70
Carpal Tunnel
Reged: 11/25/05
Posts: 2326
Loc: Missouri
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Great news, and congrats! Can't wait to hear more about your impressions.
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Todd
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w orchid
scholastic sledgehammer
Reged: 04/23/07
Posts: 832
Loc: Tampa, Fl
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Mike are you taking the new family member to CAV next weekend?
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Celestron C8 orange tube circa 1982
Stellarvue SV102ED
Celestron NS1100GPS
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CHASLX200
Carpal Tunnel
Reged: 09/29/07
Posts: 1808
Loc: Tampa area Florida
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Wonder if it would hold my 8" F8 Newt?
Chas
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tboss70
Carpal Tunnel
Reged: 11/25/05
Posts: 2326
Loc: Missouri
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I wonder how long it would autoguide with my TSA-102???
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Todd
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N7XW
sage
Reged: 05/04/07
Posts: 354
Loc: Westport, WA
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We are anxious, aren't we? Me too!! 
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N7XW
ETX125pe with UHTC
4.5" Reflector
60mm Refractor
Philips SPC900NC
Zhumell eyepieces & filters
3 sets of good ol' binocs
"Don't worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God's wondrous universe."
- Thomas M. Back, from a November 2006 interview with CN
Rest In Peace, Thomas
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Luigi
Post Laureate
Reged: 07/03/07
Posts: 4933
Loc: MA
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Can you itemize what the parts weigh? It'll resolve some contradictions in the specs from various sources.
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17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha.
Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
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dickbill
member
Reged: 09/30/08
Posts: 92
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Can you use the CG5 counterweights in the CGEM ?
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tboss70
Carpal Tunnel
Reged: 11/25/05
Posts: 2326
Loc: Missouri
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Mike! Dude, where are you? We need reports.
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Todd
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Strgazr27
Vendor - Deep Space Mods and Composites
Reged: 10/04/04
Posts: 6984
Loc: StonyHill Observatory
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--------------------
Bobby
StonyHill Observatory
Skywatcher EQ6 Pro (On it's way)
AT 130 F/6 Prototype
Royce 10" f/4 Astrograph (Under Construction)
Self Modded 40D
70-200 F2.8 L IS
SSAG
YAHOO TMB 130SS Group
Astronomy Technologies Yahoo Group
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
Mike are you taking the new family member to CAV next weekend?
Unfortunately, no. I won't be able to get back up there until January, at the earliest.
Mike
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
Can you use the CG5 counterweights in the CGEM ?
Yes!
Mike
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9050
Loc: Cloud-chester,NY
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And still no pictures. 
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"Okay! You draw the straws. I'm-a taking the parachute."
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AlienRatDog
Pooh-Bah
Reged: 07/15/05
Posts: 1086
Loc: Ann Arbor
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The suspense is too much!
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Abe -- the poor PhD student
-----------------------------------------
12" LX200GPS-SMT w/UHTC
Explore Scientific 127mm Triplet ED APO
Losmandy GM8 EQ mount
Nagler 31mm, 17mm, 13mm, 12mm, 9mm, 2.5x Powermate
12X50 Binoculars
Understanding wife
One beautiful daughter, Emma-Rose (born 7-29-2009)
Twin boys (cats), half Persian/half Alley Cat but all Vermin!
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
And still no pictures.
Evidently, anything I try to send with a photo, is NOT GOING THROUGH!
I sent a rather long "First Light" report late last night and it included a picture. It never posted!
Now, I've tried re-sending the photo twice and it never shows up.
I'll try to recreate the 'review' as soon as I can but business has me slammed today.
Anybody know if there's any way for me to retrieve that report from last night? I don't see any option for "My Postings" or anything like that in my "Home".
???
Mike
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9050
Loc: Cloud-chester,NY
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If you submitted it to the review forum, it could take a while.
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"Okay! You draw the straws. I'm-a taking the parachute."
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
If you submitted it to the review forum, it could take a while.
Nope...posted (or tried to!) it to this thread.
Mike
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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One more try with photo.
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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OK....I'm guessing I didn't reduce the photo enough and it killed the whole "First Light" post.
I'll try to re-do it tonight.
Dang-it. It was so much better when it was fresh in my mind!
Mike
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skj
super member
Reged: 04/13/07
Posts: 130
Loc: McKinney, Texas
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Great looking rig... looks extra heavy sitting by that big crack in the drive way! I can't wait to read your detailed report...
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Steve Johnson
Celestron C100ED Refractor
Celestron C6 SCT
SVP Mount on homemade tripod
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plav1959
super member
Reged: 05/10/07
Posts: 163
Loc: Central Florida
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Congrats Mike! Can I borrow it?
Paul
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Paul
14.5" StarStructure f/4.3 with AN/SC
Orion 10" Newt
William Optics Megrez 90
Orion SkyView Pro 8EQ
ETX125
Celestron CGEM mount
Celestron ASGT mount
Mallincam Color Hyper Plus
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CHASLX200
Carpal Tunnel
Reged: 09/29/07
Posts: 1808
Loc: Tampa area Florida
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Looks like the head could handle my 8" F8 Newt, but the tripod could be a problem with my long OTA bumping into it.
Now if they made a pier then maybe i would go for it.
Chas
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Yedgy
sage
Reged: 07/22/08
Posts: 457
Loc: Phoenix, AZ, USA
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Quote:
Great looking rig... looks extra heavy sitting by that big crack in the drive way!
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9050
Loc: Cloud-chester,NY
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Quote:
One more try with photo.
Jeez, you haven't had it for a day and you've already got the cords tangled! 
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"Okay! You draw the straws. I'm-a taking the parachute."
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slitherjef
sage
Reged: 09/08/04
Posts: 201
Loc: Denver CO
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Looks nice! Think it will hold a C80ed, meade 6" newt, a 20D camera and a orion starshoot autoguider, or would that be pushing it?
Can't wait to hear a detailed report and congrats on the new mount!
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-Allan
My Flickr photo page / My Blog (new)
Member of the Denver Astronomical Society
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DaemonGPF
Post Laureate
Reged: 03/22/08
Posts: 3559
Loc: New Mexico
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I'm mostly curious about the new polar alignment routine it has. If you guys haven't already, you should flip through the manual on the Celestron site. The features sound phenominal.
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-Josh
http://cleardarksky.com/c/AlbuqNMkey.html
My AP Gallery
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N7XW
sage
Reged: 05/04/07
Posts: 354
Loc: Westport, WA
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Mike,
Is your scope a modified SN8 or SN10? I dont remember and I didnt see it in your previous posts. Im curious because of the new mount size in relation to the scope. Thanks!
Jon
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N7XW
ETX125pe with UHTC
4.5" Reflector
60mm Refractor
Philips SPC900NC
Zhumell eyepieces & filters
3 sets of good ol' binocs
"Don't worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God's wondrous universe."
- Thomas M. Back, from a November 2006 interview with CN
Rest In Peace, Thomas
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
Quote:
Great looking rig... looks extra heavy sitting by that big crack in the drive way!
LOL! I've been meaning to resurface that driveway for over a year now...thanks for the reminder!!!
I'm just leaving the studio (1:30AM) so I don't think I'll be able to re-do the First Light post tonight.
Coupla' quick responses to other posters though:
*It's an SN-10 in a carbon fiber tube.
*The cords were for the Mallincam. I was in a hurry to take the photo and just left them lying there! 
*Note on Alignment: Part of my post last night related how I deliberately did NOT polar align the scope.
I just pointed it in the general direction of Polaris, making no effort to even get close.
Then I went ahead and did a two-star alignment.
The scope missed both alignment stars by at least 15 degrees, but I went ahead and centered them and hit Align.
AMAZINGLY, the mount HIT EVERY DSO I TRIED DEAD CENTER !
I don't mean the object was IN THE FIELD...I mean DEAD CENTER - EVERY TIME!
I also placed a star in a cross-hair eyepiece and just walked away and let the mount track for nearly a hour.
When I came back the star was still in the cross hairs!
From an alignment, GOTO and tracking standpoint it appears to be a quantum leap up.
Oh...and while it IS a bit noisy when slewing at high rates, it is an improvement over the CG-5 and has nowhere near the "coffee-grinder" sound of the Meades.
When tracking it is totally silent and when slewing at lower rates it is virtually noiseless.
Look at me...I was just going to write a couple of lines!
OK...one more response to several inquiries:
This is NOT really a "grab 'n go" mount! It's heavy!
And, with the SN-10, in it's Parallax rings, riding a couple of inches further out from the dovetail plate (and increasing the moment-arm)...I needed 45lbs. of counterweights!!! (The OTA w/rings, finder and eyepiece, weighs in at 30#).
Fit, finish is excellent. It REEKS of quality!
And it's absolutely rock-solid stable...no backlash or looseness at all.
OK, that's it for tonight (I think).
Mike
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skyler
Carpal Tunnel
Reged: 08/16/06
Posts: 1671
Loc: TGPNW
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How easy/effortless is the Altitude adjustments with a full load?
Thanks,
S
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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That is a great looking setup you have there. But what about vibration? With a high power eyepiece can you focus without having the image jumping all over the place. How many seconds is taking to damp back down to steady? I was thinking an 11" sct was really going to be to much for this mount to keep steady, what do you think 
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CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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N7XW
sage
Reged: 05/04/07
Posts: 354
Loc: Westport, WA
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Great first report Mike. Thanks!
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N7XW
ETX125pe with UHTC
4.5" Reflector
60mm Refractor
Philips SPC900NC
Zhumell eyepieces & filters
3 sets of good ol' binocs
"Don't worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God's wondrous universe."
- Thomas M. Back, from a November 2006 interview with CN
Rest In Peace, Thomas
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Luigi
Post Laureate
Reged: 07/03/07
Posts: 4933
Loc: MA
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What does the head weight? What does the tripod weight? No pix required to answer these questions.
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17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha.
Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
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dickbill
member
Reged: 09/30/08
Posts: 92
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Surprising: even if gotos are perfect, a rough polar alignement should create a drift, unless the mount corrects automatically in RA and Dec, based on the error in polar alignment. Damn, Celestron put some software in this mount !
Edited by dickbill (12/18/08 07:41 AM)
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AlienRatDog
Pooh-Bah
Reged: 07/15/05
Posts: 1086
Loc: Ann Arbor
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Hey Mike you should totally video tape the mount slewing and put it on youtube for us...
--------------------
Abe -- the poor PhD student
-----------------------------------------
12" LX200GPS-SMT w/UHTC
Explore Scientific 127mm Triplet ED APO
Losmandy GM8 EQ mount
Nagler 31mm, 17mm, 13mm, 12mm, 9mm, 2.5x Powermate
12X50 Binoculars
Understanding wife
One beautiful daughter, Emma-Rose (born 7-29-2009)
Twin boys (cats), half Persian/half Alley Cat but all Vermin!
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Luigi
Post Laureate
Reged: 07/03/07
Posts: 4933
Loc: MA
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>>>even if gotos are perfect, a rough polar alignement should create a drift, unless the mount corrects automatically in RA and Dec<<<
This is good, but nothing more than what tracking alt-az mounts do. They drive both axes to track. I was surprised to find that the CG5 didn't do this.
--------------------
17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha.
Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
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deSitter
Carpal Tunnel
Reged: 12/09/04
Posts: 2926
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Mike, how does it compare to the EQ6 and relatives? It also appears that the cast aluminum is coated with a sort of rubbery material, as are some binoculars - is that so?
-drl
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Alejandro
member
Reged: 08/28/08
Posts: 16
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How does it compare with CGE, the more expensive mount from Celestron?
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Project Galileo
sage
Reged: 11/14/07
Posts: 405
Loc: Douglas County, Colorado
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I find myself on the edge of my seat waiting with everyone else for any drop new gadget news. We are all like wolves greeting new wolf puppies for the first time. Swarming, sniffing, smelling, wagging our tails.
Thanks for sharing your handsome mount. I happen to like the mad scientist look of tangled chords btw. It looks like someoone is having a blast to me. Great looking and seemingly functioning mount.
Again, thanks for sharing.
--------------------
Orion XT10i
Meade LXD55 LXD75 AR-6
TeleVue Binoviewers with Seibert 1x/1.3x/1.7x OCA
Minolta 10x50 Binoculars
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
How easy/effortless is the Altitude adjustments with a full load?
You just answered it....effortless!
There's a hefty 'knob' just below the rear of the polar shaft.
You just turn that one way or another to adjust the mount to your latitude. A 'key'-type lock on the front allows you to lock it in place.
***Additional note re: Alignment.
Not only did I not polar align the scope...I just roughly set the latitude to "close to 28 degrees".
(!!!)
Mike
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
what about vibration? With a high power eyepiece can you focus without having the image jumping all over the place. How many seconds is taking to damp back down to steady? I was thinking an 11" sct was really going to be to much for this mount to keep steady, what do you think
Given that my SN-10 is longer, heavier and sits ~ 2" higher from the mounting plate than a C-11 would....I think it would handle the SCT very well!
The only instability I'm finding is in the mounting rings (which you would not have with the C-11).
Even at that, a hard rap to the OTA dampens out in ~2-seconds.
Mike
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Mert
Carpal Tunnel
Reged: 08/31/05
Posts: 1788
Loc: Spain, Pamplona
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Hi Mike,
All exiting news then and congrats on your new mount!
Would you have the oportunity to post some PE-curve?
That also is a tell-tale about the mount's performance.
Thanks,
--------------------
------------------
Mert
42º49"N 1º38"W
3" Polarex refractor
6" F12 SW Maksutov,CS2-S
EQ6 + EQMOD 
SPC900NC/DFK21AU04.AS
My web-page don't laugh, I should make it better! 
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
What does the head weight? What does the tripod weight? No pix required to answer these questions.
The EQ head (w/out counterweights) is a shade over 40lbs.
The tripod weighs in at a little over 20lbs.
Combined weight = 60+lbs.
You'll also need at least 30lbs. of counterweights for a C-11.
The mount, when purchased separately (without an OTA), only comes with one (1) 17lb. oounterweight.
Mike
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skyler
Carpal Tunnel
Reged: 08/16/06
Posts: 1671
Loc: TGPNW
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Quote:
Quote:
How easy/effortless is the Altitude adjustments with a full load?
You just answered it....effortless!
There's a hefty 'knob' just below the rear of the polar shaft.
You just turn that one way or another to adjust the mount to your latitude. A 'key'-type lock on the front allows you to lock it in place.
***Additional note re: Alignment.
Not only did I not polar align the scope...I just roughly set the latitude to "close to 28 degrees".
(!!!)
Mike
That is great to hear. Is it pushing on a plate like the cheaper mounts but just beefier or does it use an actual screw type mechanism like the Sphinx SXD/SXW?
One last about the slewing noise, I take it then that it is definitely noisier than the Atlas steppers.
Thanks and congrats !
S
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Close-up of controls on EQ head.
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Yedgy
sage
Reged: 07/22/08
Posts: 457
Loc: Phoenix, AZ, USA
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That's a hansome mount you have there, Mike! How's the polar scope? Is the Polaris HA circle finely graduated like the Tak PSs?
Tony
--------------------
The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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deSitter
Carpal Tunnel
Reged: 12/09/04
Posts: 2926
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..see that looks like rubberized armor for the brittle cast aluminum rather than paint - I've always thought that would be a good idea on mounts - so is that what I see?
-drl
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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Quote:
That's a hansome mount you have there, Mike! How's the polar scope? Is the Polaris HA circle finely graduated like the Tak PSs?Tony
Hey Tony.....THERE IS NO POLAR SCOPE!
At first I was really puzzled (and a bit miffed) that a mount of this caliber did not come with one.
THEN, after the very first alignment. I found out why -
evidently, YOU DON'T NEED ONE!
My CG-5 requires a fairly precise polar alignment in order for the GOTO to be at all accurate.
BUT...on the CGEM, a very rough polar alignment is compensated for by the onboard software (Read my earlier post).
I'll do some more testing this weekend...TRYING to make the GOTO and tracking fail!
But, so far, it is dead-on!
Mike
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Yedgy
sage
Reged: 07/22/08
Posts: 457
Loc: Phoenix, AZ, USA
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Mike,
Thanks for the quick response, but I'm confused. Does the CGEM's polar alignment routine physically move the mount in alt/az to align its polar axis with the celestial pole? Or does it use software mapping to make GOTOs accurate? The former is required for astrophotography.
Thanks!
Tony
--------------------
The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
Mike,
Thanks for the quick response, but I'm confused. Does the CGEM's polar alignment routine physically move the mount in alt/az to align its polar axis with the celestial pole?
It directs the operator to physically move the mount in alt/az to align the RA axis with the pole.
--------------------
John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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deSitter
Carpal Tunnel
Reged: 12/09/04
Posts: 2926
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That's pretty slick but I'd want a polar scope - there must be an option.
-drl
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Yedgy
sage
Reged: 07/22/08
Posts: 457
Loc: Phoenix, AZ, USA
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Quote:
It directs the operator to physically move the mount in alt/az to align the RA axis with the pole.
Sa-weet! I would love to see this! I'd also love to see a review of how well this works compared with a traditional drift alignment.
Tony
--------------------
The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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Yedgy
sage
Reged: 07/22/08
Posts: 457
Loc: Phoenix, AZ, USA
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Wait a minute, if there's no polar scope, what's that circular cap on the front of the mount and why are there finger grips on what looks like a butt cup on the back? They look suspiciously like their counterparts on my Atlas. Methinks the mount doth have a hidden secret! 
Tony
--------------------
The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
Quote:
It directs the operator to physically move the mount in alt/az to align the RA axis with the pole.
Sa-weet! I would love to see this! I'd also love to see a review of how well this works compared with a traditional drift alignment.
Tony
It's a feature common to all of the computerized EQ mounts I've owned or used. It's easy to do and about as accurate as a polar alignment scope, meaning that a drift alignment is still necessary before imaging (unless the mount is a Takahashi). I never use a PAS any more except on non-computerized mounts (where I have no choice) or on the EM-200 (which has a really, really good PAS).
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
Wait a minute, if there's no polar scope, what's that circular cap on the front of the mount and why are there finger grips on what looks like a butt cup on the back? They look suspiciously like their counterparts on my Atlas. Methinks the mount doth have a hidden secret!
Tony
A PAS is an available option.
--------------------
John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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Patrick
Postmaster
Reged: 05/16/03
Posts: 7802
Loc: Franklin, Ohio
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Quote:
My CG-5 requires a fairly precise polar alignment in order for the GOTO to be at all accurate.
Not quite true...I get dead-on gotos with my CG5 with a rough polar alignment as well. The CG5 compensates for inaccurate polar alignments and cone error.
I suspect the CGEM uses a better/newer algorithm though.
Patrick
--------------------
10" f/6 Truss Tube Newtonian
Celestron C6S-GT SCT
AT66ED Refractor
Oberwerk Ultra 15x70 Binocular
475B Geared Tripod & 501HDV Head
Celestron Regal 8x42 Binocular
Canon XSi; Meade DSI;SPC900-NC
Vixen GP2 Photo Guider Mount
My Astronomy Pages
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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NO...it doesn't "physically move" the mount to polar alignment.
I just roughly pointed the polar shaft in the general direction of Polaris.
Somehow the software calculates where it is once you enter the Alignment stars.
For long exposure imaging I would imagine that you would need to be more precise with your polar pointing.
But, I don't know for sure (yet).
It certainly did a great job "as it was"!
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
My CG-5 requires a fairly precise polar alignment in order for the GOTO to be at all accurate.
I have never, ever found that to be the case--not if you do the 2 + 4 calibration star alignment (or, with the earlier HC, the "three star"). In fact, a buddy of mine mistakenly sighted Kocab rather than Polaris through the polar bore one night and "aligned" on that. Oh, the tracking sucked, but the go-tos were still dead-on. Amazin' I calls it.
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
That's pretty slick but I'd want a polar scope - there must be an option.
-drl
You really don't need one based on my experience with Celestron's earlier polar alignment routine in the CG5. That produces an alignment somewhat better than what's usually acheivable with the polar scope, and the new routine in the CGEM may be better than that. It's lovely not to have to peer through that accursed little scope (though I must admit the Atlas has one of the better polar scopes I have used).
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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<<<Not quite true...I get dead-on gotos with my CG5 with a rough polar alignment as well. The CG5 compensates for inaccurate polar alignments and cone error......
AND WHAT ROD SAID!>>>>>>
Then I must have something entered wrong in MY CG-5, 'cause that is certainly not my experience.
I'll be glad to know if it IS "operator error"!!! 
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dickbill
member
Reged: 09/30/08
Posts: 92
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Quote:
I also placed a star in a cross-hair eyepiece and just walked away and let the mount track for nearly a hour.
When I came back the star was still in the cross hairs!
Mike
This amazes me. You can get good GOTOs with a very rough polar alignment because it doesn't depend on the polar alignment, OK, but how do you get accurate tracking ?
I don't remember anything in the instruction book pdf posted a while ago, about a routine that would correct automatically in RA and DEC for a wrong polar alignment.
This might be the end of autoguiding at short focal lenght. Amazing.
Congratulations to the celestron engineers.
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BobH
super member
Reged: 01/03/08
Posts: 143
Loc: PA
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I have been ready this thread with great interest as I really want the CGEM, but as a newbee, there is an overridding issue here.
There seems to be a huge misunderstanding, even among the vets, about the difference between polar alignment and "Go To" alignment.
I think we need not only a new thread, but perhaps a new forum...an "alignment" forum.
Regards,
Bob
--------------------
"Wise men learn more from fools than fools from the wise." - Cato the Elder
Meade 8" LX200 GPS
ETX 125 PE
Tasco 50mm x 600mm
StellarVue 115ST on MiniTower
Orion Astroview 100
Celestron 8x42 Outland LX
'03 Harley FXDL (oops, wrong forum)
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lineman_16735
Tak-o-holic
Reged: 12/04/04
Posts: 2604
Loc: Central PA
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Still, field rotation would be an issue.
--------------------
Chris
A mount from Illinois
A scope from Japan
A camera from Cal-I-Fornia
A dog from Kentucky
A wife and kids from the "Twilight Zone"
The Geek Shed
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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The manual is here CGEM Manual and it explains the process to align this mount. Also on the Celestron site they show the CG-5 polar alignment scope as one of the accessories for the cgem mount but they never mention it in the manual. They say you just make a rough alignment by looking through the hole where the polar alignment scope would normally be and put polaris in the middle of the field of view.
--------------------
CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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dickbill
member
Reged: 09/30/08
Posts: 92
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If I understand well, Mike said it did not even try to align Polaris through the hole in the RA axis, on purpose, and he didn't mention performing the polar routine either after the "3 stars alignement", so we must assume that his mount stayed misaligned.
And still, the mount kept a star in the cross hairs for an hour. This is not GOTO, this is tracking for ONE hour.
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Jeff Lee
professor emeritus
Reged: 09/17/06
Posts: 508
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BobH:
There is a difference between goto's and tracking. You can have good/great goto's (I have both Autostar/SkyAlign scopes) however with out good polar alignment tracking will suck.
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Jeff Lee
C90,C5,C8, 10 x 50's
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Ricky
Carpal Tunnel
Reged: 09/09/03
Posts: 2361
Loc: Nor Cal
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Would this be the same with an autoguider running as well?
--------------------
Regards Ricky
_______________
ADM Mount w/SiTech GoTo
WO ZS66
Orion Autoguider
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Jared
Carpal Tunnel
Reged: 10/11/05
Posts: 2529
Loc: Piedmont, California, U.S.
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Quote:
NO...it doesn't "physically move" the mount to polar alignment.
I just roughly pointed the polar shaft in the general direction of Polaris.
Somehow the software calculates where it is once you enter the Alignment stars.
For long exposure imaging I would imagine that you would need to be more precise with your polar pointing.
But, I don't know for sure (yet).
It certainly did a great job "as it was"!
Actually I am surprised at this. As far as I know, none of the GEM's currently made will make corrections in declination or right ascension while tracking to keep a star perfectly centered. No reason one couldn't, it's just that I didn't think any of them did.
Even if the CGEM is the exception and is able to keep an object centered when the polar alignment is off (certainly not a very difficult task to make those calculations), it would not be sufficient for long exposure astrophotography since it wouldn't account for the field rotation.
--------------------
- Jared Willson
- TMB 152 f/8 Apochromat
- Fluorostar FLT-110 w/ TEC optics
- Stellarvue SV80S
- Astro-Physics Mach1 GTO
- Takahashi Teegul SP Mount
- STL-11000
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Jared
Carpal Tunnel
Reged: 10/11/05
Posts: 2529
Loc: Piedmont, California, U.S.
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Quote:
Would this be the same with an autoguider running as well?
An autoguider would give you good tracking, though it would be complete overkill for visual use. However, an autoguider would not prevent field rotation, so you are still stuck with having to perform a careful polar alignment for long exposure astrophotography.
--------------------
- Jared Willson
- TMB 152 f/8 Apochromat
- Fluorostar FLT-110 w/ TEC optics
- Stellarvue SV80S
- Astro-Physics Mach1 GTO
- Takahashi Teegul SP Mount
- STL-11000
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tboss70
Carpal Tunnel
Reged: 11/25/05
Posts: 2326
Loc: Missouri
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I just want a mount that i can do 10 minute subs with. Im thinking ATLAS, or maybe this new CGEM.!!! Its looking pretty attractive!
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Todd
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9050
Loc: Cloud-chester,NY
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I'm confused. Did you just star align or did you do the PA routine. My CGE's PA routine was good enough to get 6 min exposures at 710mm with no drift or field rotation. Star aligning was good for 2-3 min.
--------------------
"Okay! You draw the straws. I'm-a taking the parachute."
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John J
super member
Reged: 11/05/07
Posts: 190
Loc: Sioux Falls SD
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With softwares like Deep sky stacker and several others, they compensate for field rotation so it is almost a moot point. Then all you have to do is crop the edges.
JJ
--------------------
Things are looking up!
http://inskysd.org/gallery/
My Flicker Astro Site
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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OK...here's what (all ) I did:
*Set the latitude scale to 28 degrees (approximately).
*Pointed the polar shaft in the general direction of Polaris (I did not look through the polar scope hole, and Polaris was not visible in the eyepiece).
*Entered the date, time, city etc., as asked for in the Align program.
*Selected "Two Star Alignment"
*Entered the first star (the scope missed it by about 15 degrees) but I centered in using the HC and hit Align.
*Ditto the second star.
*I chose a third star for callibration (it missed it by about 5 degrees but I centered it and hit Align).
That's it.
Mike
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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NOTE TO "UNCLE" ROD:
I just read your review of the Atlas EQ6 in AT&T...nicely done!
A couple of things you probably already know, but....
The polar shaft on the CGEM is heavier than the Atlas (and does not 'retract').
The CGEM also does not use the Vixen dovetail (thank heaven!). I've got my SN-10 on a 14" Losmandy plate.
The "knob" for latitude adjustment on the CGEM is WAY BETTER than the bolts on the Atlas (and on my CG-5).
There are some other "upgrades" as well.
I'm thinking the CGEM must be more closely related to the
"new" Atlas you were talking about.
Mike
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lineman_16735
Tak-o-holic
Reged: 12/04/04
Posts: 2604
Loc: Central PA
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Understood but...if you are taking many many hours of images you will have a lot of cropping to do. I prefer to crop only about 3 pixels around my images (caused by dithering).
--------------------
Chris
A mount from Illinois
A scope from Japan
A camera from Cal-I-Fornia
A dog from Kentucky
A wife and kids from the "Twilight Zone"
The Geek Shed
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Lord Beowulf
professor emeritus
Reged: 10/13/08
Posts: 674
Loc: Cedar Park, TX
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Mike,
Ok, I have a quick question for you but some of the other experts here can probably answer as well. I've been thinking of getting the CGEM for my 8" OTA from my Celestron 8se, which mounts with a Vixen style dovetail. I know the Losmandy plate is larger (4"), but at least some of the photos I've seen from Celestron seem to show a hybrid dovetail that has a V extrusion on a wider plate. That may have been for the CGE, but I don't recall. So the basic question is if the mount's at all compatible with the Vixen dovetail on my 8" OTA, or if I'll have to replace it or buy an adapter. I really hate the thought of replacing the dovetail, as I'd like to be able to keep the OTA compatible with the 8se mount for grab and go visual observing, but I don't like the thought of modding a new CGEM either!
Beo
--------------------
Celestron 8SE w/ Zhumell Focuser, Orion ST-80 & StarShoot AG. 11" NexStar GPS w/ MotoFocus.
CGEM w/ ADM Saddle, Knobs, and SBS Dual Saddles.
Modded Canon 450D & Nikon D90 DSLR w/ various adapters.
Denkmeier PowerxSwitch S2, WO 1.25" & 2" Dielectric Diags.
TV 8, 13, 17 mm Ethos, 1rpd 30 mm, Astro Tech 40 mm, Celestron 1.25" EP & filter kit.
1.25" Filters: TV OIII Filter; Lumicon selector, UHC, H-Beta, & Deep Sky.
f6.3 reducer/corrector & SCT filters.
Various custom carrying cases.
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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You just want to order one of these:
Losmandy to Vixen adpater. Converts the CGE/Losmandy Mount to Accept CG-5/Vixen style dovetail bar. Part # LOS-VIX
ADM Website
--------------------
CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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I am not sure what pictures you saw but the saddle on the CGEM is not a dual saddle it only mounts Losmandy D-series bars, so you need the adapter I mentioned in the previous post.
--------------------
CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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According to the Manual (and verified in the photos in same) the CGEM takes EITHER the LARGE Vixen-style dove-tail OR the Losmandy plate.
Notice the size of the receiver and the two large tensioning knobs.
Mike
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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"Uncle" Rod will be happy to note that the azimuth knobs have been made much larger and that there is more than adequate clearance for tightening.
Edited by Mike Harvey (12/19/08 06:36 AM)
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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The "screw-on" power cord is a welcome addition.
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plav1959
super member
Reged: 05/10/07
Posts: 163
Loc: Central Florida
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Hey Mike,
Just wondering if the counterweight shaft is any shorter than the CG5 leading to the need for more weight?
--------------------
Paul
14.5" StarStructure f/4.3 with AN/SC
Orion 10" Newt
William Optics Megrez 90
Orion SkyView Pro 8EQ
ETX125
Celestron CGEM mount
Celestron ASGT mount
Mallincam Color Hyper Plus
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Luigi
Post Laureate
Reged: 07/03/07
Posts: 4933
Loc: MA
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Quote:
Quote:
My CG-5 requires a fairly precise polar alignment in order for the GOTO to be at all accurate.
Not quite true...I get dead-on gotos with my CG5 with a rough polar alignment as well. The CG5 compensates for inaccurate polar alignments and cone error.
I suspect the CGEM uses a better/newer algorithm though.
Patrick
Yeah but it doesn't correct dec while tracking to compensate for poor polar alignment.
--------------------
17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha.
Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
<<<Not quite true...I get dead-on gotos with my CG5 with a rough polar alignment as well. The CG5 compensates for inaccurate polar alignments and cone error......
AND WHAT ROD SAID!>>>>>>
Then I must have something entered wrong in MY CG-5, 'cause that is certainly not my experience.
I'll be glad to know if it IS "operator error"!!!
I would guess it probably is pilot error. Everybody I know of with this mount hasn't had to worry about dead-on polar alignment (that does help the LXD 75). If you don't get good go-tos from just sighting Polaris through the polar bore, somethin' is awry.
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
|
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Quote:
This amazes me. You can get good GOTOs with a very rough polar alignment because it doesn't depend on the polar alignment, OK, but how do you get accurate tracking ?
I don't remember anything in the instruction book pdf posted a while ago, about a routine that would correct automatically in RA and DEC for a wrong polar alignment.
This might be the end of autoguiding at short focal lenght. Amazing.
Congratulations to the celestron engineers.
With a low power eyepiece, a middlin' good polar alignment--just eyeballin' Polaris--will keep objects in the field for a suprisingly long time.
Be careful what you wish for. The "driven dec" routine on some Vixen mounts has literally given imagers fits--and I don' mean no "flexible image transport system."
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
Edited by rmollise (12/19/08 10:32 AM)
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
With a low power eyepiece, a middlin' good polar alignment--just eyeballin' Polaris--will keep objects in the field for a suprisingly long time.
Be careful what you wish for. The "driven dec" routine on some Vixen mounts has literally given imagers fits.
Yes. With a one degree visual FOV, a few arcminutes of drift won't be noticeable at all - but for imaging we are concerned with arcseconds.
The mixed tracking mode available in the Vixen SS2K can be turned off, and should always be disabled for imaging. I've seen reports of a similar mode in the Starbook, but haven't seen any way to turn it on or off (and never noticed my Starbooks doing it). Meade's "DEC compensation" feature is pretty good at compensating for DEC drift on a given object, though. That's because it is trained for that specific object only.
--------------------
John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
Would this be the same with an autoguider running as well?
For imaging, you can get away with slight polar alignment as long as your exposures don't run on too long. If they do, you get trailing from field rotation. Even if you autogide perfectly, you will still get this field rotation. Driving the declination axis will not help either; you will _still_ get field rotation.
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
Edited by rmollise (12/19/08 10:22 AM)
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
"Uncle" Rod will be happy to note that the azimuth knobs have been made much larger and that there is more than adequate clearance for tightening.
My pore fingers will be very happy. I actually managed to cure--or at least lessen--the aziumuth problem by means of leaving the "tripod rod" a little loose, and putting a thin coating of bicycle chain grease on the tripod head, but larger knobs would be VERY welcome...my paddy paws hurt for a dadgummed week after my first run with the Atlas...
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
|
rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
|
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Quote:
Yes. With a one degree visual FOV, a few arcminutes of drift won't be noticeable at all - but for imaging we are concerned with arcseconds.
The mixed tracking mode available in the Vixen SS2K can be turned off, and should always be disabled for imaging. I've seen reports of a similar mode in the Starbook, but haven't seen any way to turn it on or off (and never noticed my Starbooks doing it). Meade's "DEC compensation" feature is pretty good at compensating for DEC drift on a given object, though. That's because it is trained for that specific object only.
It's nice to know that it can be turned off on the SS2K. The StarBook does indeed have this feature, though I was under the impression it could be disabled there too. I would hope so.
Me? I don't want this kinda "help" with a GEM.
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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mclewis1
Thread Killer
Reged: 02/25/06
Posts: 3941
Loc: New Brunswick, Canada
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Beo,
You are indeed likely thinking of the orange extruded CGE rail. Without anything to provide an accurate scale it does look like a vixen compatible (1.75") rail on a Losmandy D compatible (3") rail. It really isn't ... those wider rails for the CGE are only Losmandy D sized ... the extra material on the edges of the rail provide a more solid mounting to those larger OTAs used in the CGE series.
Other Celestron scopes also have the smaller vixen compatible rails (orange for the ASGT series and black for the SEs), and the orange ones do look somewhat like a miniature version of the CGE model.
--------------------
Mark
C11, C6, APM/TMB115, and AT80ED - Tandem mount CGE and CG-5A, WO EZ-Touch and AT Voyager
25x100s and 8x56s, T-Mount Light, Mark 1 eyeballs - Modded 350D, DSI-P, SPC900, Mallincam
Just because you can doesn't necessarily mean that you should
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skyler
Carpal Tunnel
Reged: 08/16/06
Posts: 1671
Loc: TGPNW
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I will be really anxious to see how well it guides for AP work. Everything else, except maybe the noise level, seems to be better or the same as the Atlas. The main mechanical issue was the Alt adjusts for me and that is addressed.
If this mount can produce the same or better PE as the Atlas and can be autoguided as well or better than the Atlas and its steppers, then that will be the clincher for me.
Hope someone can do some guided AP soon.
S
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dickbill
member
Reged: 09/30/08
Posts: 92
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Maybe Mike was actually well aligned.
According to his report, he set the mount at 28 degre, it seems correct for Florida especially if the latitude scale is more accurate in the cgem, then maybe he got the azymuth right by pure luck.
This would explain how one star could stay in the cross hair of a reticulated eyepiece for almost an hour.
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deSitter
Carpal Tunnel
Reged: 12/09/04
Posts: 2926
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Could someone comment on the black material that covers the cast aluminum mount parts? Is that simple paint, a paint-like robust cover, or rubberized armor as in some binoculars? Thanks in advance.
-drl
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tboss70
Carpal Tunnel
Reged: 11/25/05
Posts: 2326
Loc: Missouri
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Quote:
...as long as your exposures don't run on too long. If they do, you get trailing from field rotation.
Rod, how long is too long? 5 minutes? 10 minutes?
Just curious,
Thanks.
--------------------
Todd
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
Rod, how long is too long? 5 minutes? 10 minutes?
Just curious,
Thanks.
It depends on your focal length and how far "off" the pole you are. With a polar alignment using the Atlas polar scope (I'm fairly careful to get this just right) I can go 3 - 5 minutes at about 1300mm without a problem.
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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DaemonGPF
Post Laureate
Reged: 03/22/08
Posts: 3559
Loc: New Mexico
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I'm curious to hear about imagers experiences with this mount as well. Getting a good Go-to for visual is one thing, running 10 and 20 minute exposures without drift or rotation is another. It sounds really promising though.
I'm happy to see the adjustment knobs, those little screws on the CG5 are a huge pain sometimes.
--------------------
-Josh
http://cleardarksky.com/c/AlbuqNMkey.html
My AP Gallery
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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Quote:
According to the Manual (and verified in the photos in same) the CGEM takes EITHER the LARGE Vixen-style dove-tail OR the Losmandy plate.
Notice the size of the receiver and the two large tensioning knobs.
Interesting - I missed that in the manual.
But what do you mean by LARGE Vixen...
I thought there was just V-Series and D-Series, is there a 3rd one Assuming this does allow the V-series plate to be attached, it looks like only one side of the saddle moves, that means the telescope will be offset on the mount, I wonder if that will cause a balancing issue.
--------------------
CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
Assuming this does allow the V-series plate to be attached, it looks like only one side of the saddle moves, that means the telescope will be offset on the mount, I wonder if that will cause a balancing issue.
That'd be one issue. Another is that the shapes of the dovetails are very different; a saddle that fits one well will not be able to hold the other securely even if the width difference is somehow accounted for.
--------------------
John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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dickbill
member
Reged: 09/30/08
Posts: 92
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This issue about the rail is going to be recurrent as many users will be upgrading from the CG5, or vixen style, rail.
Personnaly I would prefer NOT using an adapter, I'd rather replace my CG5 rail with a new wider one for my C9.25 OTA.
So, is it possible to simply unscrew the CG5 style rail off my OTA and put a new CGE style rail instead ?
This question is going to be asked thousands of time.
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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I think the C9.25 will really benefit from a bigger dovetail. I just ordered a Losmandy D-Series dovetail for my C9.25 so I can use it on my future CGE or now maybe my future CGEM. Just when I had already decided on the CGE they have to introduce this new mount to confuse me all over again. That dovetail was 130 bucks at OPT, there are probably some cheaper ones out there someplace, but I couldn't find them.
--------------------
CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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BobH
super member
Reged: 01/03/08
Posts: 143
Loc: PA
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Quote:
BobH:
There is a difference between goto's and tracking. You can have good/great goto's (I have both Autostar/SkyAlign scopes) however with out good polar alignment tracking will suck.
Jeff,
Why would tracking be any different than an infinite series of gotos?
Thanks,
Bob
--------------------
"Wise men learn more from fools than fools from the wise." - Cato the Elder
Meade 8" LX200 GPS
ETX 125 PE
Tasco 50mm x 600mm
StellarVue 115ST on MiniTower
Orion Astroview 100
Celestron 8x42 Outland LX
'03 Harley FXDL (oops, wrong forum)
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Lord Beowulf
professor emeritus
Reged: 10/13/08
Posts: 674
Loc: Cedar Park, TX
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You know, it would really be nice if there was a good reference somewhere showing the dimensions of the various extrusions. Not having a good local telescope retailer that I can go visit, it's really a pain in the @#$% trying to figure out the differences in what everyone's selling! I plan to get out to an AAS meeting at some point so that I can see some of the other members' stuff, but given the cloud cover in the area I doubt that tomorrow night's public viewing is going to happen!
Beo
--------------------
Celestron 8SE w/ Zhumell Focuser, Orion ST-80 & StarShoot AG. 11" NexStar GPS w/ MotoFocus.
CGEM w/ ADM Saddle, Knobs, and SBS Dual Saddles.
Modded Canon 450D & Nikon D90 DSLR w/ various adapters.
Denkmeier PowerxSwitch S2, WO 1.25" & 2" Dielectric Diags.
TV 8, 13, 17 mm Ethos, 1rpd 30 mm, Astro Tech 40 mm, Celestron 1.25" EP & filter kit.
1.25" Filters: TV OIII Filter; Lumicon selector, UHC, H-Beta, & Deep Sky.
f6.3 reducer/corrector & SCT filters.
Various custom carrying cases.
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mclewis1
Thread Killer
Reged: 02/25/06
Posts: 3941
Loc: New Brunswick, Canada
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Quote:
That'd be one issue. Another is that the shapes of the dovetails are very different; a saddle that fits one well will not be able to hold the other securely even if the width difference is somehow accounted for.
From the current pictures I can't see how the CGEM saddle would hold both types. But until there are better pictures of the saddle I'll reserve judgment. It is however quite easy to create a saddle that can handle both types of dovetails ... just have a look at what Anthony at ADM has been doing for a little while with his "Dual Saddle device".
John, from what I've seen Anthony's new saddle design holds either type of dovetail equally well. The smaller vixen compatible portion is not as deep as some vixen only saddles but when tightened down there wouldn't appear be any issues.
Link to ADM saddle
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Mark
C11, C6, APM/TMB115, and AT80ED - Tandem mount CGE and CG-5A, WO EZ-Touch and AT Voyager
25x100s and 8x56s, T-Mount Light, Mark 1 eyeballs - Modded 350D, DSI-P, SPC900, Mallincam
Just because you can doesn't necessarily mean that you should
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
John, from what I've seen Anthony's new saddle design holds either type of dovetail equally well. The smaller vixen compatible portion is not as deep as some vixen only saddles but when tightened down there wouldn't appear be any issues.
Now that's clever!
Anthony makes nice stuff. I would NEVER have thought of making two sets of jaws, one above the other, like that.
It should work just fine.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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JAT Observatory
Got Cookies?
Reged: 02/20/05
Posts: 6784
Loc: Eastern PA
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Quote:
Actually I am surprised at this. As far as I know, none of the GEM's currently made will make corrections in declination or right ascension while tracking to keep a star perfectly centered. No reason one couldn't, it's just that I didn't think any of them did.
The Paramount ME will do just that when the ProTrack option is enabled.
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-Marcus
The problem with free speech is even the stupid have a voice.
http://www.jatobservatory.org
Currently a SV102A, WO 66mm & 10" LX200GPS OTA on a Paramount ME
(these OTAs subject to change without notice)
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Dave H.
sage
Reged: 02/29/08
Posts: 219
Loc: Northern Virginia
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dickbill, I'm with you and would certainly prefer to mount the dovetail right to the OTA. Your vixen stlye dovetail will come right off by simply taking out the allen head bolts on both sides. Going to the larger Losmandy style rail you will probably need to use radius blocks, and Losmandy has a nice C.925 dovetail kit with radius blocks for for about $90 if I remember correctly.
So, is it possible to simply unscrew the CG5 style rail off my OTA and put a new CGE style rail instead ?
This question is going to be asked thousands of time.
--------------------
CPC1100XLT
CGEM Mount
Skywatcher Pro 120 ED
Celestron C6XLT
Baader Modified Canon 450D, and far too much other stuff!
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Lane
Pooh-Bah
Reged: 11/19/07
Posts: 1495
Loc: Frisco, Texas
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Quote:
So, is it possible to simply unscrew the CG5 style rail off my OTA and put a new CGE style rail instead ?
This question is going to be asked thousands of time.
You can definitely do it as long as your C9.25 is the standard style tube and not the new fancier looking tube they use on the CPC fork mounts. I don't know if they have a dovetail for those CPC types yet. I got mine at OPT, it is the Losmandy D-series dovetail. ADM currently does not have one listed on their site but they probably will soon and no doubt it will be cheaper than the true Losmandy version.
--------------------
CGEM, ORION SIRIUS, AT Voyager
OTAs: C6, C8, C9.25, C11, Pronto, ED80
Orion 9x63, Fujinon 10x50 & 16x70
Ethos 13, 17 Nagler 9t1,12t4,16t2,22t4 Panoptic 27,35
Antares 1.6x, TV Powermates 2x & 4x, TV Barlow 3x, TV Plossl 8,11,13
Baader Hyperion 21, 8-24 Zoom, UO HD Ortho 6,7,9,12,18
TMB Planetaries 3.2,4,5,6,7,8, Pentax XW 10,14,40
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WadeH237
sage
Reged: 02/24/07
Posts: 498
Loc: Snohomish, WA
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Quote:
Why would tracking be any different than an infinite series of gotos?
I suppose there would be no practical difference if that's what a tracking mount did.
In the case of most GEMs, tracking is done by running the RA motor at a constant speed, with the dec motor off.
After the two star alignment, the mount "knows" how it is oriented to the sky, including polar alignment error. It also "knows" as it tracks that it is moving off target due to that error, and by exactly how much. When you do another goto, it will have no problem centering the new target, regardless of whether polar alignment and tracking are poor.
There is some suggestion in this thread that the CGEM may actually use the dec motor to make adjustments during tracking. All alt-az mounts with tracking have to do this, but few GEM mounts do it. As has been suggested, having the dec motor run during tracking (other than as directed by a guider) generally hinders astrophotography as opposed to helping it.
Based solely on the information in this thread, the jury is still out as to whether the mount does dec corrections. I am guessing that it does not (none of the other Celestrons do.) I am inclined to think that the OP got lucky on the setup and that the polar alignment was just close.
I would love to see a definitive clarification on this point.
Thanks,
-Wade
--------------------
http://www.faintfuzzy.net
Stuff
Visual Stuff (shared with wife and kids, 10 & 12): Generic 6" F/8 Dob, C8-SGT, CGE-1400, Orion ED80 on a CG5-GT, Coronado PST, 6" Meade Schmidt-Newtonian, Astroscan, 12x70 Binoculars.
Imaging Stuff: Meade 8" LX200ACF with Optec TCF-S focuser on a CGE mount, SBIG ST-10XME with CFW8 and remote guide head, Astro-Tech AT66ED guide scope, Astrodon filters, QHY8PRO, DSI Pro, Canon EOS 20D, Hyperstar 3 for C8.
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WadeH237
sage
Reged: 02/24/07
Posts: 498
Loc: Snohomish, WA
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Quote:
So, is it possible to simply unscrew the CG5 style rail off my OTA and put a new CGE style rail instead?
Maybe. It probably depends on your OTA. On something like a C8 or larger, you could definitely install a Losmandy D dovetail. I've done this on my imaging OTAs for using my CGEs. I would not want to try it on something like an 80mm refractor.
I've got the ADM adapter and it is a life saver. Since I got both CGE and CG-5 mounts, it gives me flexibility with my smaller OTAs to use any of my mounts. Also, Losmandy D dovetails are not exactly cheap. If you have several OTAs, you'd likely be better off with the adapter.
Also, I've found that the ADM adapter is pretty beefy. It's plenty rigid to attach my ED80 with a piggy-backed AT66ED for photography.
Thanks,
-Wade
--------------------
http://www.faintfuzzy.net
Stuff
Visual Stuff (shared with wife and kids, 10 & 12): Generic 6" F/8 Dob, C8-SGT, CGE-1400, Orion ED80 on a CG5-GT, Coronado PST, 6" Meade Schmidt-Newtonian, Astroscan, 12x70 Binoculars.
Imaging Stuff: Meade 8" LX200ACF with Optec TCF-S focuser on a CGE mount, SBIG ST-10XME with CFW8 and remote guide head, Astro-Tech AT66ED guide scope, Astrodon filters, QHY8PRO, DSI Pro, Canon EOS 20D, Hyperstar 3 for C8.
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Mike Harvey
professor emeritus
Reged: 03/01/04
Posts: 692
Loc: Orlando, FL.
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[quote I am inclined to think that the OP got lucky on the setup and that the polar alignment was just close.
I would love to see a definitive clarification on this point.
-Wade
Hi Wade...
I'll, hopefully, be able to get back out with the CGEM this weekend and I'll make sure I'm NOT polar aligned!
Then I'll see what happens and report back.
Mike Harvey
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BobH
super member
Reged: 01/03/08
Posts: 143
Loc: PA
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Quote:
Quote:
Why would tracking be any different than an infinite series of gotos?
I suppose there would be no practical difference if that's what a tracking mount did.
In the case of most GEMs, tracking is done by running the RA motor at a constant speed, with the dec motor off.
After the two star alignment, the mount "knows" how it is oriented to the sky, including polar alignment error. It also "knows" as it tracks that it is moving off target due to that error, and by exactly how much. When you do another goto, it will have no problem centering the new target, regardless of whether polar alignment and tracking are poor.
Wade,
Thank you very much. That's very interesting. I wonder why, if the scope "knows" where it is during tracking, that it can't be programmed to adjust both dec and ra?
This is getting way off topic, but you said "most" gems track that way. Do you know of any that do correct dec while tracking?
I'm beginning to think I should just stay with alt-az. These gems don't seem to be worth the expense and hassle.
Thanks,
Bob
--------------------
"Wise men learn more from fools than fools from the wise." - Cato the Elder
Meade 8" LX200 GPS
ETX 125 PE
Tasco 50mm x 600mm
StellarVue 115ST on MiniTower
Orion Astroview 100
Celestron 8x42 Outland LX
'03 Harley FXDL (oops, wrong forum)
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
I wonder why, if the scope "knows" where it is during tracking, that it can't be programmed to adjust both dec and ra?
It could, but since folks are usually just barely able to settle for the tracking precision of one motor in constant motion, tracking performance with that plus another motor operating intermittently would probably satisfy nobody (unless the precision is extremely good, as in the case of $10,000 mounts). A slow DEC drift is, in general, greatly more desirable than a series of stairstep "bumps" in DEC. The best and easiest solution is simply to use a good polar alignment so no significant DEC drift occurs and no corrections are necessary.
--------------------
John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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WadeH237
sage
Reged: 02/24/07
Posts: 498
Loc: Snohomish, WA
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Quote:
I'm beginning to think I should just stay with alt-az. These gems don't seem to be worth the expense and hassle.
That's not a bad idea. In my opinion, alt-az mounts are better than GEMs for visual work.
Once you start doing astrophotography, you will learn a whole new definition of the word 'hassle'.
I should also point out that even alt-az mounts turn off the dec tracking motor when you set them up on a wedge in equatorial mode - which you would generally only do for photography.
-Wade
--------------------
http://www.faintfuzzy.net
Stuff
Visual Stuff (shared with wife and kids, 10 & 12): Generic 6" F/8 Dob, C8-SGT, CGE-1400, Orion ED80 on a CG5-GT, Coronado PST, 6" Meade Schmidt-Newtonian, Astroscan, 12x70 Binoculars.
Imaging Stuff: Meade 8" LX200ACF with Optec TCF-S focuser on a CGE mount, SBIG ST-10XME with CFW8 and remote guide head, Astro-Tech AT66ED guide scope, Astrodon filters, QHY8PRO, DSI Pro, Canon EOS 20D, Hyperstar 3 for C8.
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JAT Observatory
Got Cookies?
Reged: 02/20/05
Posts: 6784
Loc: Eastern PA
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Quote:
Quote:
Why would tracking be any different than an infinite series of gotos?
I suppose there would be no practical difference if that's what a tracking mount did.
....snip....
After the two star alignment, the mount "knows" how it is oriented to the sky, including polar alignment error. It also "knows" as it tracks that it is moving off target due to that error, and by exactly how much. When you do another goto, it will have no problem centering the new target, regardless of whether polar alignment and tracking are poor.
]
There is a bit more to it than just correcting the inaccurate polar alignment. There are things that effect the mount as it is commanded to go to a new position. The center of gravity changes because of balance, there may be flex in tube or the camera attachment, etc.
Those things also effect the scope while it is tracking only the effect happens at a much slower rate (sidereal rate) instead of the slew rate as when a normal goto is executed.
Normal gotos can be corrected by pointing correction software, like MaxPoint, TPoint or Meade's Smart Mount. The correction software accounts for repeatable errors, like backlash, flexure, balance as well as poor polar alignment. The problem is those conditions and the error'ed pointing must be modeled.
While the poor polar alignment can be characterized during the alignment routine the repeatable pointing errors can only be characterized by building a pointing correction model of the sky. So even if the tracking was reduced to a series of gotos, eventually those gotos would need to be corrected. I have yet to see a mount that has perfect pointing right out of the box. While the pointing may appear to be acceptable at lower FLs, increasing the FL to 2000+ will quickly make the the errors visible.
The Paramount corrects its tracking in both Ra and Dec when the Protrack software is enabled. Protrack uses the same pointing correction model that was built to correct the gotos, to correct the scope during tracking. Since the model has knowledge of the errors Protrack uses that to "apply small, periodic corrections" to improve the unguided tracking.
Bisque claims the process will allow unguided exposures up to 20 minutes up to about 2540mm of focal length. I would assume that is under prefect conditions. I have not achieved those numbers, but I can routinely go 10 minutes unguided with my 12" SCT at about 1922mm using ProTrack. But it should be noted my current correction model contains hundreds of mapped points and my setup is permanently mounted.
So while it can and is being done, it is not a simple align and go, the software does not all reside in the mount, and it requires prior setup.
Having said all of the above and based on the first light report, the CGEM does appear to have raised the bar and given other mounts in its class a target to shoot for.
--------------------
-Marcus
The problem with free speech is even the stupid have a voice.
http://www.jatobservatory.org
Currently a SV102A, WO 66mm & 10" LX200GPS OTA on a Paramount ME
(these OTAs subject to change without notice)
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Lord Beowulf
professor emeritus
Reged: 10/13/08
Posts: 674
Loc: Cedar Park, TX
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Quote:
You are indeed likely thinking of the orange extruded CGE rail.
Yup, that's the one!
Beo
--------------------
Celestron 8SE w/ Zhumell Focuser, Orion ST-80 & StarShoot AG. 11" NexStar GPS w/ MotoFocus.
CGEM w/ ADM Saddle, Knobs, and SBS Dual Saddles.
Modded Canon 450D & Nikon D90 DSLR w/ various adapters.
Denkmeier PowerxSwitch S2, WO 1.25" & 2" Dielectric Diags.
TV 8, 13, 17 mm Ethos, 1rpd 30 mm, Astro Tech 40 mm, Celestron 1.25" EP & filter kit.
1.25" Filters: TV OIII Filter; Lumicon selector, UHC, H-Beta, & Deep Sky.
f6.3 reducer/corrector & SCT filters.
Various custom carrying cases.
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Chris Rowland
sage
Reged: 02/28/05
Posts: 267
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I've been beta testing the new software (on an AS-GT) and as far as I know there is no tracking compensation for a polar align error. If there was then drift aligning would be impossible without turning this off and I don't know of any option to do this. So I guess that Mike's good tracking was because his polar alignment was accidentally good - or at least the pole, mount Ra axis and object were in a straight line.
I think that the new AllStar polar alignment method is wonderful! It encourages you to use a star that's on the meridian and not too high. It's a two stage process, first you do a sync to the star using the HC buttons, then you use the mount mechanical adjustments to do the polar alignment. Afterwards there is NO NEED TO REALIGN!!!
The polar alignment seems to be very good, I've taken multiple 120 second unguided exposures over more than an hour and stacked them with Deep Sky Stacker. This calculates the rotation required to do the alignment and it is zero. That's no field rotation over an hour.
What I'd say is "Don't get a polar alignment scope, get a reticle EP instead".
Chris
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Scott Beith
SRF
Reged: 11/26/03
Posts: 37127
Loc: Frederick, MD
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Quote:
Quote:
My CG-5 requires a fairly precise polar alignment in order for the GOTO to be at all accurate.
Not quite true...I get dead-on gotos with my CG5 with a rough polar alignment as well. The CG5 compensates for inaccurate polar alignments and cone error.
I suspect the CGEM uses a better/newer algorithm though.
Patrick
I agree with Patrick on this one.
--------------------
   SLAP Observer (TMB130SS, SV102V, SV80ED)
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Dennis Sakva
Pooh-Bah
Reged: 10/19/04
Posts: 1306
Loc: Kiev, Ukraine
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Now, lets see some Periodic Error graphs! One picture worth at least 1000 bytes
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Ennis
sage
Reged: 09/11/06
Posts: 328
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Quote:
According to the Manual (and verified in the photos in same) the CGEM takes EITHER the LARGE Vixen-style dove-tail OR the Losmandy plate.
Notice the size of the receiver and the two large tensioning knobs.
Mike
WHERE in the manual does it say this? I cannot find it.
Thank you.
Ennis
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
Quote:
According to the Manual (and verified in the photos in same) the CGEM takes EITHER the LARGE Vixen-style dove-tail OR the Losmandy plate.
Notice the size of the receiver and the two large tensioning knobs.
Mike
WHERE in the manual does it say this? I cannot find it.
Thank you.
Ennis
And what is a "large" Vixen dovetail?
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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Scott Beith
SRF
Reged: 11/26/03
Posts: 37127
Loc: Frederick, MD
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does it have the same database as the CG-5?
--------------------
SLAP Observer (TMB130SS, SV102V, SV80ED)
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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rmollise
Post Laureate
Reged: 07/06/07
Posts: 4561
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Quote:
does it have the same database as the CG-5?
That's what I've been told, and I wouldn't expect otherwise.
--------------------
Uncle Rod
Rod's New Book:
Choosing and Using a New CAT
Available now!
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Alejandro
member
Reged: 08/28/08
Posts: 16
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As specs say, the payload will be up to 40 pounds. Well, the 1100 OTA weights 28 pounds, if I add a side by side dove tail plate (7.5 pounds), and an orion guidescope (2 pounds), with its rings and plate (4.75 pounds), it's a bit exceeded the 40 pounds. Anyway, celestron promotes the CGEM1100, which is a bundle of a C11 OTA and the CGEM. It seems strange to me that 40 pounds limitation and the Celestron CGEM1100 offer. Besides, if one takes into account the counterweights needed the excess is total. I don't think counterweights count in the payload, but I'm not sure, and besides a CGEM1100 is in the limit of working specs. I cannot understand. Am I wrong?
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25185
Loc: NE Ohio
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Quote:
As specs say, the payload will be up to 40 pounds. Well, the 1100 OTA weights 28 pounds, if I add a side by side dove tail plate (7.5 pounds), and an orion guidescope (2 pounds), with its rings and plate (4.75 pounds), it's a bit exceeded the 40 pounds.
Yup. If you take a CGEM1100 and add enough extra weight to increase the load by 50% you'll exceed the ratings. Lots of mounts are offered in bundles in which adding 50% more would exceed the specs. If you plan to do that you need to start with a mount offering a 50% margin.
You mention a guidescope so it's possible that you are considering imaging. If so, the manufacturer's weight spec needs to be derated by nearly 50% anyway - 25 pounds would be a realistic imaging load if the visual spec is 40 pounds. 40 pounds is a realistic imaging load for a CGE; that would be a better candidate.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 178ED F/9 "APO"
Meade ETX-125AT
C14
Teeter 20" F/3.8 truss Newt w/ServoCat
CI-700, NJP, GPDX/SS2KPC, CG5-GT
ST-10XME, DSI Pro
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BobH
super member
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