CGEM: What's the truth?
Posted 29 March 2010 - 09:46 AM
The CGEM seems (from the reports on this forum) to have its share of "teething" issues. My goal is to get a more balanced perspective as to whether the CGEM is a gremlin-ridden nightmare or basically a sound product with a few units missing the mark.
If you own or have owned a CGEM, please share your experiences both good and bad. If your use has been trouble free, please share as this is the kind of data that seems underrepresented.
Posted 29 March 2010 - 10:41 AM
In my opinion, you settled on the perfect design for visual; the fabulous Celestron alt-azimuth mount. All the noises it makes are totally normal and harmless.
Posted 29 March 2010 - 10:45 AM
Posted 29 March 2010 - 10:46 AM
Posted 29 March 2010 - 11:36 AM
It's heavy, so one must learn to lift it onto the tripod in one fluid motion without having to shift one's grip. Also, there is, at times, some very slight play in Dec, when the scope points in a certain direction, but it's only apparent when the scope or part of it is touched.
Even being aware of all of this, I'd still buy the mount again.
Posted 29 March 2010 - 11:39 AM
Posted 29 March 2010 - 11:52 AM
It is a very reliable performer.
Just this past weekend, I imaged with it again from my back porch - this time with NO polar alignment and stretching my image time from 10 minute subframes to 15 min subs. I imaged M108 under the 99 percent Moon for 75 minutes using those 15-min subframes. The only alignment done was the built-in All Star alignment procedure, using four calibration stars. Goto's are perfect when I use four calibration stars. the ST2000 camera does not have such a large chip in it.
But the GOTO's will always put the object very near center of my chip's FOV unless I'm swinging the mount all the way around, doing a polar flip.
This image was internally guided with the ST2000's built in guide chip, using 5 second pulses. The image shows good, round stars even though no drift or polar alignment was done. The only exception is the top left of the image, where my shots always show footballs because the camera doesn't sit in the SV90T APO squarely.
Posted 29 March 2010 - 11:54 AM
I have had mine (new) for two months.
Here's a Leo Trio taken from this mount at ARizona Sky Village two weeks ago
Posted 29 March 2010 - 12:13 PM
Posted 29 March 2010 - 12:20 PM
I'm actually considering upgrading my Atlas to a CGEM.
I have seven OTAs and three EQ mounts currently, in addition to the CPC.
Posted 29 March 2010 - 01:09 PM
Posted 29 March 2010 - 01:59 PM
Posted 29 March 2010 - 02:12 PM
My CGEM does a great job, I have never had a problem. Visually, it is perfect. Once I got trained on using it, the object is in the central part of the field of view everytime. Until I let the battery get too low. Blame it on the human.
Photographically, I only do piggybacking. I have a 300mm lens and as long I keep the tracking accurately, it tracks smoothly and the images turn out great. For wide field stuff with my 35mm lens, I can go over the do some binocular observing while the CGEM tracks.
I also replaced the knobs, they were just too slippery. I bought from Scope Stuff.
Lots of fun;
Posted 29 March 2010 - 02:16 PM
Posted 29 March 2010 - 02:32 PM
Posted 29 March 2010 - 02:48 PM
Posted 29 March 2010 - 02:48 PM
Posted 29 March 2010 - 03:01 PM
Posted 29 March 2010 - 03:51 PM
Posted 29 March 2010 - 07:19 PM
This is my 2nd scope. The first was an LX200 so have had a little problem getting use to GEM.
I am very happy with the CGEM.
Posted 29 March 2010 - 08:49 PM
Posted 29 March 2010 - 09:04 PM
The instruction manual is something I would expect from a really cheap setup from Wally World.
The adjustment for Dec sux big time if your down around 30 degrees like I am.
On the other side, it has some neat features & if they can get my problem (Gear mesh I think)fixed I will be satisfied with it.
I guess what bugs me the most is that I would have been happy to spend a couple of hundred more on the mount if they would have fixed these & some other minor issues that would not have cost them much to have done right the first time.
Posted 30 March 2010 - 01:28 AM
Posted 30 March 2010 - 01:41 AM