EQ mount for local Astrophotogrpahy

[kimo]

Hi,

I need advice on EQ mount for local Astrophotogrpahy. I am planing to setup an EQ mount with autoguider. I prefer to have a light weight mount that I can move around easily. Which mount should i purchase?

Telescope and Camera: 80mmED Refractor, Canon EOS camera
Autoguider Guider : 102mm Refractor (5lbs), Orion Autoguider.

I also have other SCT Telescopes: C5, C6, C8, 10 (26lbs)"

Regards
Kimo

[orly_andico]

hi Kimo

based on my own experience, with a payload that heavy, you need at least a CGEM / Vixen SXD / Atlas / Losmandy GM8 / Takahashi EM-200 class mount.

if you are willing to use a finder guider (50mm finder) instead of the big overkill guider you are currently contemplating, then maybe you can get away with using a Vixen SXW / Great Polaris / Great Polaris DX or D2 class mount. But you would have no more room for expansion.

if you want to carry your other scopes as well, then definitely a CGEM / Atlas / etc. would be the minimum. Don't expect to image with those tubes (well a CGEM or Atlas can handle a C9.25 with the f6.3 reducer).

i guess the most pertinent question is, what is your budget.

right now there is a used Celestron CGE on the cloudy nights classified for $1700 USD shipped (within the US). that's $2100 SGD + about $400 SGD for shipping to SG. if you can swing that budget, that would be the best buy, as the CGE is made in the USA (unlike the CGEM and Atlas) and has a 65lb payload (probably 35-40lb for imaging). You could spend the rest of your astro hobby lifetime with such a mount...

[cloud_cover]

Hi Kimo!
Like Orly, I think the main overkill you have there is the guidescope: Its bigger than your imaging scope! Having said that, what's the total weight of your setup?
I used the Sphinx SXW previously without autoguiding on a VMC200L (!) It did decently although it was hobbled by a very unsteady tripod. It will comfortably handle your setup if you downsize your guidescope or if its particularly light. I think there's 2 on sale at the moment. Do bear in mind its PE is probably somewhere in the 30arcsec range and its not considered one of the "premium" mounts for AP.
Having said that, the short focal length of an 80mm (it's not like an f/10 or f/16 achromat, right?) will forgive a multitude of "sins"
Be aware when buying most other mounts except the Vixens - to the best of m knowledge, they all require modifications or extra parts to reach down to 0 deg latitude. Locally the Skywatcher/Orion mounts will be modified by local vendors but as you can read from previous threads, Orly had to go to great trouble to manufacture his own wedge for the CGEM. Nothing wrong, really, but just be aware The Losmandy/Astro-physics mounts do have specific adapters you can buy, but for extra cost. So do check the latitude range of the mount before you buy so that you are aware.
Also be aware your Meade 10" is at the limit of the SXW's capacity. I assume you will want to occasionally mount it for visual fun
Bear in mind too that you will need a half-pier or some sort of extension to avoid the counterweight bar from hittng the tripod legs.

[orly_andico]

The great thing about the CGE is the built in electronics pier. Losmandy has a similar concept. But imho a 40lb meade 10" on an SXW is a very bad idea. Heck it would be a bad-ish idea on a 45lb rated Atlas / CGEM. Then theres the hassles of non premium mounts.

Frankly if you can swing it, go for a Mach1 or AP900. Used preferably so you dont get hit by the depreciation. But then that assumes you wanna get Really Serious (tm). Less serious, find a G11 Gemini 1, used.

OK, let me make some revisions.

1) as someone who has gone through an entire range of mediocre to middling mounts, I would say if you have the money or can accumulate it over some time go straight to the AP. I have (or had) a Vixen Polaris, Vixen Great Polaris (with Vixen dual drive), CGEM, and AP600. If I add up all the money I spent on those mounts, I could have bought a Mach1. No kidding. One went for US$5000 yesterday on a-mart.

That really pisses me off.


2) if you have no intention or desire to spend $7000+ on a mount, I would say look at the iOptron iEQ45. What makes it so special compared to the Atlas and CGEM? one word - weight. Consider, the CGEM and Atlas EQ heads weigh 40lb, and carry 45lb (maybe 25lb for imaging).

The AP600 head weighs about 32lb, and carries 25lb for imaging. The Mach1 head weighs 29lb, and carries 45lb for imaging. In other words, you can image with a C11 on a Mach1, and it only weighs 29lb.

do note that the accessories for the AP mounts such as tripods etc. are frightfully expensive - the Rob Miller Tri36L is probably the best buy because it "only" costs US$1100 - but it weighs 9lb and carries 200lb (compare to $1550 for the Eagle pier; and $750 for the wood tripod which carries much less). Versus say a CGEM/Atlas tripod which weighs 30lb.

the iOptron iEQ45 weighs 25lb - and carries 40-45 (same at Atlas/CGEM). So the weight issue is not inconsiderable.


3) personally I think the Takahashi mounts are overpriced, although the same guy who sold the Mach1 for US$5000 has an NJP for the same price. I would not buy Takahashi new. Their wood tripod costs US$800 for cryin' out loud!


4) Vixen is also overpriced and has burned the community by not fixing the declination guiding bugs in the starbook. Instead they come out with a new $11000 Vixen AXD with Starbook Ten and throw all the existing starbook users to the wolves. Nobody in their right mind would buy an $11000 Vixen mount when you can get an AP900 or Paramount MX for less.


5) Losmandy is the darling of the mid-price mount crowd, simply because nobody sells a decent mount in the US$3000 range. But the Gemini II is still buggy. Buy a used G11 Gemini I for US$1800 and be happy..

[orly_andico]

Oh and another thing... I am beginning to become a convert to Off-Axis Guiding, even on a refractor. Now if only I could get my hands on an OAG to try it out..

You could save a ton of payload by using a lightweight OAG. Teleskop-Service (Germany) sells an ultra-low profile but rather pricey OAG - it's over $300 but is very thin and very well-made.

Here's that $1700 CGE -

http://www.cloudynights.com/ubbthreads/ ... ost5057697

Note that you'd need to eventually get the Gary Bennett cables (the design flaw of the CGE is the RJ-45 motor cable jacks which break quickly).

[kimo]

After some read I understood that Orion Sirius EQ-G mount is much lighter then Atlas EQ-G. I don't know how is the PE. anyone having this mount?

[orly_andico]

After some read I understood that Orion Sirius EQ-G mount is much lighter then Atlas EQ-G. I don't know how is the PE. anyone having this mount?

Tim has one.

It is much lighter than the Atlas, but is not much cheaper ($1100 vs $1400 USD). And its rated payload is only 30lb - take 1/2 of that off for imaging.

If I were making this choice and the weight really mattered, I'd go with an iEQ45. I think some folks here on have it.

[cloud_cover]

I think the best weight to performance ratio is probably the Vixen mounts. The SXW/SXD is comparatively light for Eq mounts and they do have a decent payload.
Also, they can adjust down to 0 deg latitude (the iEQ 45 and Atlas can too, with modifications)
They perform well although stock, the Starbook sofrware is plagued by sudden jerks in the Dec axis. The NexSXD upgrade fixes this issue.
Basically you have to decide how heavy and long your equipment will be. If you're using a normal APS-C sized DSLR and an ED80, your resolution is about 2.3 arcsec/pix; the finer your resolution (longer focal length or smaller pixel pitch), the more precise your mount needs to be
Just to ask: What's your budget?

[shirox]

you can get a gm8 with mini borg 50
been there done that and tested proven to work.
with goto is a bonus.

You will appreciate a losmandy.

[kimo]

My friend want to sell his Orion sirius EQ-G mount. he no longer interested on AStronomy. I am planing to buy it.

Is this mount gear quality same as Atlas EQ?