Which mount? (for FSQ-106)

[slt (Gunther)]

Hi everyone!

New user ... though I've been lurking for a while. Not new to the hobby, but have had a break from it for a while. Grew up with binos and eventually a 6" Newt back in the late 70s but then always lived in places where it rarely ever got really dark

Anyway, I recently bought the kids a C6SE (wish I'd had that when I was their age, but never mind ) and I think I caught the bug again. So got myself some 16x70 binos, thinking that would cure it ... but it didn't!

So .... have set myself the challenge and take up photography, and more or less decided on a Tak FSQ-106. Not entirely sure on the mount though, but weighing up Tak and Losmandy. I need something reasonably portable (since I still live where it doesn't get dark but at least now I have a car), and something able to comfortably handle the 106 with the nexessary attachments. On spec the Em11 and the GM8 sound like they should be able to handle the above, but never having used either, would I be better off with EM200 or G11 instead (obviously considering the extra $$$ and additional bulk as well)?

I've pretty much read every review on those four mounts that I could find, so I think I'm reasonably comfortable with their strengths and weaknesses (I guess mostly strengths). But any advice is appreciated

Cheers!

[AlexN]

What camera are you intending to use... there can be a lot of variation in overall imaging system weight depending on the camera used... For example, a DSLR weighs in at about 1kg, where as a large format CCD camera with a filter wheel and filters can weigh in at over 2kgs depending on make/model.. some of those CCD's being self guided reduce the overall weight by not requiring a separate guide scope and guiding camera...

I would say that a Losmandy GM-8 would easily carry the FSQ106, an 60~80mm guide scope + all the extra ancillaries required.. The G11 would handle it better, but I think it could be overkill unless you're looking at adding some really heavy imaging equipment as well...

There are quite a few people using the Losmandy GM-8 mounts on these forums, I know of one who's using one with a 110mm F/7 triplet APO which I dare say when you add in all the guiding bits and bobs would weigh in at quite a bit more than the FSQ106..

That being said.. The mount is the most important part of an imaging system. The best camera and optics on a lower end mount are going to give you lower end results... Over mounting is the key. Add up the total weight of everything you intend to have on your mount. Scope, Guide scope, camera, guide camera etc... Then go and buy a mount that will handle 150 ~ 200% of that weight... The GM8 will handle 15kgs or there abouts (according to the product specifications) I would aim to have the entire imaging setup between 7~9 kgs on that mount. The G11 on the other hand will handle quite a bit more... Having 20kgs on a G11 for photographic use is not out of the question...

It really comes down to what you can afford, but in my opinion its better to sacrifice a little on your camera and optics than on your mount...

[Hagar (Doug)]

If I were you I would base the purchase on a number of issues:
The weight of the total instruments to be carried The FSQ isn't a light scope. If a guide scope and guide camera are required this is again extra weight your mount must carry. Try not to load your mount above 2/3 of it's rated capacity if you want good results.

The weight you yourself can handle in a mount.

The stability of the mount and tripod.

Think ahead to plan for any future expansion.

The overall performance of the mount with respect to guiding etc.


The old rule for equipment purchases for astrophotography has always been mount, moumt, mount. Thousands of dollars worth of telescopes and cameras on a substandard mount will only produce sub standard images.
I have a G11 and would recomend at least this size and quality of mount, It's extremely stable, has good load carrying capacity, nice big RA and Dec gears to guide smoothly and can take a knock without to much movement.
It is more expensive than some of the mounts available at the moment but has a proven track record.

Good luck with your purchase.

[montewilson (Monte)]

Go the EM-200. I have one and it is unbeatable for performance and accuracy. It held an FSQ and an FS-60c and an STL-11000 and an STV and had no problems with that load.

The polar scope is fantastic and will get you to about 2' of the pole in a few minutes. It talks to TheSky with no probs.

I could be interested in selling mine I'm 50/50 about it but if you are keen PM me.

[rally]

Gunther,

I dont think the EM11 with a full astrophotography rig is really a contender.
The EQ6 is a cheap copy of the EM200.
It will not perform as well as an EM200 in terms of its mechanical precision (PE, backlash etc), but it will interface with EQMOD and many people are successfully using it as entry level astrophotography mount.
So long as you get a Temma2 version of the EM200, it will talk to most (all?) of the serious packages.

The FSQ is a very rear heavy scope, when you add a heavy camera and filter wheel etc, it gets even heavier at the rearend, so you need to consider this when you set it up.
You cant just slide it forward because the camera/filterwheel runs into the mount - the OTA rings want to be higher than normal so you can clear the dovetail with the dewshield and move things as much as possible and with a heavy camera you may even need a front counterweight - (guidescope).
For an electronic focusser you have to very carefully work out your backfocus, otherwise use the existing rack and pinion and a Robofocus, for camera rotation - nothing beats the Takometer on the original CAA - you only lose a few mm of back focus with this device.

Cheers

[slt (Gunther)]

Thanks guys! Exactly the sort of info I was looking for. Although I will probably start off using my DSLR, I will soon be wanting something from SBIG, and so the whole assembly will grow. Better to factor that in now rather than to have to upgrade the mount.