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Best reflector for AVX or ZEQ25?

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#1 Bill McNeal

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Posted 19 July 2013 - 11:13 PM

I'm wondering about GoTo reflectors on GEM mounts, particularly the AVX. I thought Celestron sells the AVX mount with 10" reflector, but I only see the 8" Celestron version for sale in this combo. Does the 10" combo exist or does the AVX owner have to get the 10" OTA separately?

The AVX has a 30 lb. payload, 10" reflector OTA is 28 lbs. Or is that too heavy?

#2 SeattleScott

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Posted 20 July 2013 - 05:54 AM

Including tube rings, dovetail bar and finder scope, the Celestron 10" OTA is about 32 lbs. That is before you drop a heavy 2" eyepiece in the focuser. Celestron used to sell their 10" on the slightly lighter duty CG5 so obviously it would work on the VX. But the fact that Celestron does not package them together suggests that it really isn't a recommended combination. You might consider a custom lighter weight design instead, like Orion optics VX series, but that will cost you. Or you can get a Dob. Or an even heavier eq mount then the VX.

#3 Bill McNeal

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Posted 20 July 2013 - 07:12 PM

Thanks. Do you think the ZEQ25 would be able to handle this payload? I saw a thread discussing it can handle a payload far above its rated amount. This is primarily for visual.

#4 Kendahl

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Posted 21 July 2013 - 09:54 AM

Orion sells its 8 inch Newtonian (weighs 16.5 lb) on three mounts. They are the SkyView Pro (20 lb capacity), Sirius EQ-G (30 lb capacity) and Atlas EQ-G (same as EQ-6, 40 lb capacity). They only sell their 10 inch (weighs 27 lb) on the Atlas. After you add tube rings, dovetail, finder and eyepiece to the 10 inch, you will be over 30 lb.

In another thread, I asked about the 8 inch on the Sirius mount for astrophotography. The consensus in reply was that the scope plus tube rings, dovetail, autoguider and camera would be too much weight on the mount. It would be ok for visual. (I ended up buying an iOptron iEQ45 and a William Optics GTF102.)

I am thinking about buying Orion's 10 inch Newtonian to put on the iEQ45. It would be for visual only because I suspect it would be too heavy for photography. For that I expect to need a Losmandy G11 or Astrophysics Mach1.

Orion sells GoTo Dobs up to 16 inches. If you don't want to do photography, one of them would be a better setup.

#5 Bill McNeal

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Posted 21 July 2013 - 06:17 PM

Thanks Kendahl.

The reason I suspected these two mounts could handle a 10" Newt (27 lb. OTA) is because Celestron sells the 11" SCT on an AVX mount (also 27 lb. OTA).

I had not considered a Dob because I might want to do AP with this mount in the future. Are there ergonomic advantages to a Dob over a GEM Newt?

How do you like your IEQ45? I would think that if the ZEQ25 can handle the 10" Newt for visual, the 45 should be able to take it for AP.

#6 SeattleScott

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Posted 21 July 2013 - 10:37 PM

The difference is the 27lb reflector OTA does not include rings, dovetail bar and finder scope. Add those and I think you are at about 32 lbs. The SCT has no need for rings and comes with a built in dovetail bar. Also the SCT is much shorter so it will not catch the wind as much.

The ergonomics of a Dob are the eyepiece position (eyepiece position will change depending on where you point an eq mount) and the chair, for those who prefer observing from a seated position. An extra tube ring will help a lot with the tube rotation issue for an eq mounted reflector, but there is no way you are going to be seated in a chair. Personally I like eq reflectors, but then I prefer to stand while I observe too. Call me a freak.

#7 Bill McNeal

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Posted 21 July 2013 - 11:04 PM

Thanks Scott. What is that 10" scope you have on the VX in your sig?

For awkward eye piece placement, isn't that solved by rotating the OTA?

Besides cost, any downsides to getting a 11" on the AVX vs. a 10"
Newt on a iEQ45 or CGEM?






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