Which Mount for Astrophotography?

[Matty P (Matt)]

Hi all,

After getting my feet wet with a bit of DSO imaging and crossing over to the “Dark Side”. I have decided that I want to upgrade to a new mount (when the funds allow) suitable for long exposure imaging. I want the mount to be stable enough for long exposures and have GOTO. I would also like the mount to be able handle a larger scope in the future.

I will be using my Celestron 8” SCT OTA as the main imaging scope and hopefully my 80mm refractor as a guide scope. The camera I will be using is still a work in progress, either a Meade DSI or a DSLR.

After a bit of research I have found the EQ5 mounts are good for telescopes up to 12 inches. Therefore being a total newbie to this, I have no idea what is the best mount for astrophotography on a budget of no more than $2000.

Any suggestions?

[madtuna (Steve)]

There are some remarkable photos on this site, and I've witnessed many at the astro club I am a member of done using the EQ6 PRO.

Andrews have them delivered free Australia wide to your door for $1799

[dugnsuz (Doug)]

Originally Posted by Matty P

After a bit of research I have found the EQ5 mounts are good for telescopes up to 12 inches. Therefore being a total newbie to this, I have no idea what is the best mount for astrophotography on a budget of no more than $2000.

Any suggestions?

If you could stretch that budget by about $500, choice would be the Losmandy GM8 new (2nd hand cheaper, but rare as hen's teeth).
https://www.bintelshop.com.au/Images/Stock/7523X.jpg

EQ5 and a 12" scope would be a pretty unstable pairing I reckon

I only have an ED80 and 80mm guidescope on my EQ5 for astrophotography, and I wouldn't want to add any more weight to it!

Cheers
Doug

[Matty P (Matt)]

Thanks Madtuna and Doug,

How does the Losmandy GM8 and the Skywatcher EQ6 Pro compare to each other?

Which one is better in terms of tracking and long exposures?

[rogerg (Roger)]

Originally Posted by Matty P

How does the Losmandy GM8 and the Skywatcher EQ6 Pro compare to each other?

The GM8 will give you better tracking but not hold as much weight.

You probably don't want to put more than a 8" SCT on a GM8. But it will hold large refractors (WO FLT110 for example) so is still very flexible.

$2000 is a tall ask for something up to 12", I would say close to impossible (depending on how much perseverance you have).

I haven't used an EQ5/6 or anything like that, but I have a GM8.

I wouldn't want to use a scope for astrophotography that doesn't have PEC and PC interface to allow autoguiding. I'm guessing to get a GM8 under $4,000 you need to get it just with steppers, no Gemini unit included, which would (I think) greatly hamper your astrophotography success.

For that reason, for under $2000 I would be considering the cheaper chinese stuff like the EQ's more than the Losmandy type stuff.

I used to do all of my astrophotography on a old EQ2 comparative mount ($300 ish). It was wobbly as anything. I got good shots, but it took a lot of perserverance to get there, and the attitude of "use what you have to the max". So you can do stuff with cheaper mounts, and smaller mounts, and similarly you could probably overload the Losmandy GM8 somewhat, but it just makes it all harder.

I do'nt have enough experience with other mounts to really comment much more sorry.

[dugnsuz (Doug)]

Originally Posted by Matty P

Thanks Madtuna and Doug,

How does the Losmandy GM8 and the Skywatcher EQ6 Pro compare to each other?

Which one is better in terms of tracking and long exposures?

Hi Matty,
Here's a recent heated debate by those in the know regarding your very question...

http://www.iceinspace.com.au/forum/s...ad.php?t=26499

Also here's a spec sheet on the GM8...

http://www.bintel.com.au/LosmandyGM8.html

and here, ($100 cheaper from peter Ward!)
http://www.atscope.com.au/losmandy.html

GM8 has both PEC and an autoguider port for imaging.

All the best
Doug

[Matty P (Matt)]

Thanks for the links Doug,

Like I said before I would like the mount to be suitable for long exposure imaging but at the same time won’t break the bank.

The GM8 is without a doubt a better mount overall in build quality etc, except when compared to the EQ6. In my opinion the EQ6 comes out on top in terms of price and functions.

The maximum weight the GM8 can carry is only 13.5kg compared to the 20kg the EQ6 can carry. Not much room for a larger OTA in future. Also for that price, the GM8 does not come with a GOTO function either.

I still need to do some more research on both of these mounts.

[leon]

Reading this post and the fores and against, to certain mounts etc, it really cames down to what it is going to carry and the amount you have in the bank, and can afford.

If money is not an issue you cannot go past the Losmandy G8 or G11, absolutely superb, however if the funds only stretch to the limit you have stated, than you are limited to the cheaper mounts, which however will do a great job as well.

leon

[Peter Ward]

This has been done to death elsewhere, but in short, the fewer guiding corrections you have to perform, the better the image.

Standard EQ5/6's typically run close to an arc minute in periodic error.

G-8 typically +/- 8 arc sec. G-11's +/- 5 arc sec.

Figures will vary if you Google various web sites, but I'd suggest the above is pretty typical.

So, the question becomes, do I want something built to a specification or a price?

[g__day (Matthew)]

I posted this awhile ago - might turn it into an article

* * * A definitive guide to goto mounts

http://www.iceinspace.com.au/forum/s...highlight=goto

[Peter Ward]

Well, depends upon what you class as definitive.

This is also interesting

http://www.eisystems.be/astronomy/EQ...k_PE_graph.jpg

[skwinty (Steve)]

Originally Posted by Peter Ward

Well, depends upon what you class as definitive.

This is also interesting

http://www.eisystems.be/astronomy/EQ...k_PE_graph.jpg

Hi Peter
I am directing this question to you as you seem to be very knowledgable with regards to all kinds of mounts and equipment.
The link you provided wrt eq6 mount was last updated in 2005. I know that there were many problems regarding finish and types of grease used. Has there been any improvement in the eq6 pro mount since 2005.
I have recently bought an eq6 pro and yes it was bought to price rather than specification.
I would have loved to spend more on a paramount but here in south africa you take the dollar price and multiply by at least 10.
So you will appreciate R12,000 for and eq6 versus R120,000 for Paramount ME especially if you do not have a permanent observatory.
As soon as my rig is operational i would like to post some of my pix for positive criticism which would help in furthering my education in this fascinating field.

Kind Regards
Steve.

[Kal (Andrew)]

A good website, albeit in French, that shows various mounts Periodic Error performance is at http://demeautis.christophe.free.fr/ep/pe.htm

[Zuts]

Originally Posted by Matty P

Hi all,

After a bit of research I have found the EQ5 mounts are good for telescopes up to 12 inches. Therefore being a total newbie to this, I have no idea what is the best mount for astrophotography on a budget of no more than $2000.

Any suggestions?

Getting back on track, and keeping your budget in mind i don't think an EQ5 would be suitable for your scope. Fortunately the price difference between a HEQ5 with goto and an EQ6 Pro with goto is less than 200 dollars and under your stated budget.

I was a bit aprehensive buying my EQ6 but i got it and it worked out fine, with guiding i can get 10 minute subs with no trailing using my F7 Televue 85. I havnt tried longer as i image with a DSLR and noise would make this pointless. Your mileage with the C8 may vary as it has a longer focal length but since you are a 'newbie' try the reverse and image through the 80mm and guide with the C8.

If you look at photo's taken by members, see EZYSTYLES and ICEMAN you will see some wonderful work all done on an EQ6.

It's not a G11; but for the price, an EQ6 pro offers great value. A 20kg load easily, PEC, an autoguiding port, upgradeable GOTO. I would say go for it

Paul

[Peter Ward]

Hello Steve,

It all comes down to tracking accuracy vs focal length.

With Deep Sky imaging the longer the FL, the harder it is to get nice tight round stars. You can put an camera with a 16mm lens on a garden rock, expose for 30 seconds, and it will give you needle like stars.

Now you could argue garden rocks track "really well" but at 1600mm the rock just doesn't cut it

My experience it at around 1800 to +2500 mm FL tracking inaccuracy really starts to hurt image quality.

On a tight budget I'd personally choose a G-8 or Vixen without the GoTo bells and whistles as they do nothing for imaging quality.

Suffice to say they are many, many views on this. I suppose the best way to sift through it all, is look similar subject matter, comparing the image scale, focal length and depth then try and compare "apples with "apples"

Cheers
Peter

Originally Posted by skwinty

Hi Peter
I am directing this question to you .....


.....As soon as my rig is operational i would like to post some of my pix for positive criticism which would help in furthering my education in this fascinating field.

Kind Regards
Steve.

[madtuna (Steve)]

Originally Posted by Peter Ward

Hello Steve,

It all comes down to tracking accuracy vs focal length.

With Deep Sky imaging the longer the FL, the harder it is to get nice tight round stars. You can put an camera with a 16mm lens on a garden rock, expose for 30 seconds, and it will give you needle like stars.

Now you could argue garden rocks track "really well" but at 1600mm the rock just doesn't cut it

My experience it at around 1800 to +2500 mm FL tracking inaccuracy really starts to hurt image quality.

On a tight budget I'd personally choose a G-8 or Vixen without the GoTo bells and whistles as they do nothing for imaging quality.

Suffice to say they are many, many views on this. I suppose the best way to sift through it all, is look similar subject matter, comparing the image scale, focal length and depth then try and compare "apples with "apples"

Cheers
Peter

don't discount the garden rock...you never see one come up in the ice trade classifieds..people tend to hang on to them

[skwinty (Steve)]

Hi Peter
Thanks for the reply.
However I asked if you thought there has been an improvement in the eq6 pro since 2005 which was the last time your reference was updated. I did not ask for sarcastic remarks relating to garden rocks or other statements of fact.
I asked the question hoping for an informed and educated answer considering all the comments you have made previously.
Obviously I was mistaken.
Regards
Steve

[g__day (Matthew)]

Steve,

Why would a dealer and enthusist in high end gear (Peter) know all the ins and outs of the low end entry platform? And if he did don't you think he would have told you?

My views

A EQ5 won't cut it for a 12 inch scope - an EQ 6 will be a basic platform that with tuning and skill will produce results - provided you tune everything and master it - absolutely everything - especial if you're think long focal lenght imaging and lengthy exposures of dim objects - that's your worst case torture test.

You will live and die in your attempts at the harder end of of imaging - by focus, rigitidy of the rails and guide scope, precision of focus during the entire the exposure, Q/E (signal / noise) of the imaging camera, tracking of the mount - if it were easy - monkeys would do it.

Reduce Peter's advice down to modest mounts and large heavy optics means modest focal length targets and as you increase your focal lenght - lower your exposure time (i.e. choose brighter, easier targets) until you're really profficient.

Then there's the whole world of mastering imaging processing...

[skwinty (Steve)]

Hi g__day
Had no idea that Peter was a dealer.I could tell he is an enthuisiast for high end equipment. It just that the amount of EQ6 bashing he does, I would have thought he had some experience with them.
For example he states tracking error to be up to 1 arc min. however that figure relates to the go-to pointing accuracy. The general consensus on the eq6 forum is that the tracking accuracy is about +- 10 arc secs which is not that far of the high end equipment. Quite easily guided to better handle the error.
The majority of bad reports of eq6/5 etc relates to older equipment and apparently skywatcher has taken note and made improvements. In future I will remember that Peter obviously has a vested interest in the equipment he is an agent for.
Thanks for the heads up.
Regards
Steve

[g__day (Matthew)]

Steve

Peter runs http://www.atscope.com.au/ - and a quick glance will show you its all very high quality gear. Peter is giving you honest and unbiased advice - a mount manufactured for $2,000 won't have the precision in its gears of one costing double, triple or alot more.

I've seen PE curves of +/-20 arc seconds of PE - will will infer tracking error for EQ6 on the French site above Kal gave you. A Takahashi mount will probably be around +/-3 arc seconds - but with no PEC - a high end Vixen can probably achieve +/- 3 arc seconds with PEC.

Interpret what Peter said - if you want to do 20 minute plus shots at 2m focal lengths you need great tracking performance. My mount seems to be running an arc second per minute fast in RA - enough to ruin 10 minute shots at 2.3 metres (I've just upgraded SkySensor2000-PC EPROMS to the latest version 2.10) so fingers crossed this helps tracking rates.

Peter can't really defend himself here - but I will say I know only one skilled person who was ever miffed with him and all his advice he has posted here has been right in the gold. He's not snowing you just read his gear choices are for folk going for shows that run to hours skies permitting. His typical client might spend $15 K on a entry level high range purchase once you add mount G11, CCD and OTA - and at the high end of what he offers - I wouldn't expect change from $70K if you play with large RCOS OTA and research grade CCDs on a PME.