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losmandy gm8 vs celestron cgem?

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#1 orionn1

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Posted 24 March 2014 - 11:44 PM

looking at purchasing a new /used losmandy tripod mount gm8 or celestron cgem? Anyone out there with some input and opinions.
I had a CG5 before.
regards
I will be using a es125 with a canon camera.
thanks

#2 EFT

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Posted 25 March 2014 - 01:46 AM

looking at purchasing a new /used losmandy tripod mount gm8 or celestron cgem? Anyone out there with some input and opinions.
I had a CG5 before.
regards
I will be using a es125 with a canon camera.
thanks


If you are use to the Nexstar already, then you will of course find the CGEM easier to use. Quality of the machining in the GM8 is much higher but the Gemini goto is more difficult to use. The rated capacity of the GM8 will not be much more than the CG-5, but it will probably handle it a bit better. The CGEM will have the better capacity overall. In the realm of mounts, the GM8 is more on the CG-5 level while the G11 is more on the CGEM level. Comparing the GM8 and the CGEM is sort of looking a two different mount classes.

#3 RAKing

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Posted 25 March 2014 - 07:04 AM

The major difference between these is the carrying capacity - and the QUALITY of the mount. Losmandy products are beautifully machined and work great. Celestron uses cast aluminum and mass production.

The Gemini system is no more difficult to learn than the Celestron hand paddle and the Gemini can build a very nice pointing model by starting with a single star.

The GM-8 is the smallest Losmandy mount and is rated for 30 pounds. This works fine for visual loading (I carried a TMB 130 on mine) and the smaller Losmandy tripod is more rigid than many think. I use the lighter tripod under my Mach 1 many nights because it's easier to haul around than my Eagle Pier and is just as steady for visual observing.

The only downside to the GM-8 is that capacity might be too low for your desired load and you might consider the G-11 mount - which is far above the CGEM in quality and capacity (and unfortunately price).

Cheers,

Ron

#4 gdd

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Posted 25 March 2014 - 10:50 AM

The GM-8 and G11 are closer to the CGEM in price if you don't get the Gemini GOTO. You will still be able to track when using your Canon camera. Is your camera a DSLR?

Gale

#5 orionn1

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Posted 25 March 2014 - 06:37 PM

yes it is a t3 dslr

#6 nganga

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Posted 25 March 2014 - 06:43 PM

The Gemini system is no more difficult to learn than the Celestron hand paddle and the Gemini can build a very nice pointing model by starting with a single star.


Agree. The Gemini hand control is not at all complicated to use. If you do not have to hop from object to object, a single GoTo Bright Star + Sycnhronize puts the target close to the center when you slew to it. Of course, the more stars you add to your model, the more robust the pointing.

I still have my CG5 and I sometimes wish that it had the large screen of the Gemini instead of that scrolling one-line display.

Clem

#7 gezak22

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Posted 29 March 2014 - 05:44 PM

looking at purchasing a new /used losmandy tripod mount gm8 or celestron cgem? Anyone out there with some input and opinions.
I had a CG5 before.
regards
I will be using a es125 with a canon camera.
thanks


I've found my GM8 to be a HUGE leap forward in terms of guiding accuracy when compared to my CG5. I used the GM8 for over a year before upgrading to something that was more robust on windy nights. By the time I sold the GM8, it was carrying a 13 lbs load and I consistently got sub arcsecond guiding accuracy - perfect for widefield imaging. I should stress that I was the fourth owner of the GM8, and I had to replace the worms on both axes with high precision worms (and the one piece worm block) before the performance was consistent. Also for widefield imaging, I found the manual setting circles more than sufficient - no need for go-to.

Now on to your specific needs: I'm worried that the moment arm of the es127 (f/7.5) is too long, and the GM8 might be at its comfort limit. I'd recommend a used G11 with high precision worms and one piece worm blocks on both axes - you should be fine without the Ovision worm. Used G11s are hard to find without go-to, so the price might exceed your budget. At it's native focal length (952 mm), you'll be better off with go-to.

I've had bad experiences with my CG5, so I vote for staying away from Celestron. I found the GM8 to be very reliable. If something is not right with the mechanics, then anybody who can replace brake pads on a car can fix whatever is wrong the GM8. I assume the G11 is similar in that respect.

Edit: Please be sure to read through all the points being made in this thread.

#8 Geo.

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Posted 31 March 2014 - 11:55 AM

I have a G11 will be going on the block. PM me if interested.

#9 astrophile

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Posted 02 April 2014 - 11:11 PM

I'm worried that the moment arm of the es127 (f/7.5) is too long, and the GM8 might be at its comfort limit.


Definitely an issue if you're going to do AP. GM8 would be a good visual mount for this scope but at its limit. G-11 better choice for your described use.






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