Mounts: 10Micron versus ASA

[FrancoRodriguez]

Hi all, I'm in the market to get a shiny new mount for a shiny new observatory (that Isn't there yet!). The mount will be on a pier.
I'm tossing up between a 10Micron GM2000HPS versus an ASA DDM100 (The DDM85 is out of production now:shrug:). They both have absolute encoders. The former has a worm gear; the latter direct drive. A distant third might be the paramount but with no encoders I'm really leaning away from this. I'd love to stop guiding if at all possible, for 1/2 hour shots.
I'm really not planning on imaging with anything more than 45kg so the 100kg capacity of the ASA is really nice but not required. I'm planning on using a Planewave CDK 12.5 or 14, depending on budget, with a 100mm SW Esprit piggybacking on top. The ASA would cost quite a bit more than the 10Micron.
Does anyone have any thoughts on the matter? Money certainly is a factor to consider, particularly as I don't yet have a big reflector or for that matter a really big chip (planned for 16803).
Any advice, recommendations, pitfalls to consider, good or bad reports would be greatly appreciated!
Clear skies everyone!

[gregbradley]

Paramounts can be ordered with encoders.

AstroPhysics mounts also can be ordered with encoders and can also be retrofitted with them with a kit.

As to how well either of these go on a CDK12.5 or 14 unguided for 30 minutes I don't know. That sounds like a tough test.

Perhaps ask Roland Christen direct at the AP Yahoo Group.

Greg.

[Atmos]

I have an ASA DDM60 (hasn’t been in production for around 2 years) and it is hands down my best Astro purchase. Haven’t guided since purchasing it and until recently I’ve not found a reason to.
I’ve had one night out with a Mewlon 250 at 0.4”/pixel (http://www.astrobin.com/full/412985/C/) and as you can see it’s tracked perfectly for 300s exposures but I at tempted to add an OAG as a safety net and run 10-15s exposures. I’m also running close to the 20-25KG capacity though and you’d be at around 50%.

I’ve done a lot at 1.16”/pixel with a 130mm refractor for 10 minutes and comfortably been able to get FWHM down to 1.7 pixels (seeing limited). Everything is about being able to create an accurate sky model. I don’t have a permanent setup and usually do 20-30 points which takes 10 minutes and allows the 300s exposures that I need.

With the Mewlon I did a process called MLT or something along those lines which does an optimising run of what you’re going to image for an even more accurate tracking model of a specific part of the sky.

Between ASA and 10 Micron one of the major differences between them comes down to the software. All ASA mounts are tied into their software packages; Autoslew to control the mount (connects to other software packages via ASCOM) and Sequence for creating the pointing models.

10 Micron can be entirely controlled via their hand controller. A few years ago a CN member wrote some software that ties their mounts into MaximDL for creating the pointing models.

[FrancoRodriguez]

@atmos thanks for replying. Unfortunately they don't make the 60 or 85 any more. The smallest is 100. It's bound to be quite a lot more expensive than the 10micron 2000HPS but holds 2x the weight. Also, it has direct drive. My biggest fear, of course, living in AUstralia, is that if anything goes wrong it needs to be shipped back to Italia. I've heard that ASA don't care much for us puny peasants. They deal more with governments and universities. True or false? This is a really big factor for me.

[FrancoRodriguez]

I'm aware of the AP and SB mounts able to have encoders but I'm a little dubious at their performance. AP reckons they can install it post market which I imagine would be a huge feat, no? Furthermore, AP has a crazy waiting time. The SB mount with encoders does look great but they don't come standard, a big minus in my books. It makes it seem that they don't have as much experience with them. Any opinions would be greatly appreciated

[Atmos]

I know some people have talked about the potential issues of power failure with direct drive mounts but having used one for a while even if slewing at maximum speed and a power failure happened, it slows down pretty darn quick.

You do make a good point with regards to sending it back to Italy, getting a mount back to Austria or USA.
I don’t think ASA is that difficult to deal with, they’re certainly isn’t much support at times like with documentation or fixing some of the software glitches that have popped up over the years but when someone gets into trouble I’ve heard they’re fairly supportive.

[Peter Ward]

Colin's results not withstanding, it really depends on how deep and well resolved you want your data.

If you shoot at 500mm to 1100mm, then accurate tracking is a no-brainer for many mounts. But when you shoot at 3400mm on a good night, i.e. FWHM's under 1.8 arc sec, all I can say is: lots of luck with absolute encoders.

I constantly see stars move in RA and Dec....due to no fault of the mount, just the atmosphere doing its thing.

I have have yet to see an unguided mount produce tighter stars than a guided
mount. If I use an AO then I see up to a 30% improvement in FWHM's

I'll also be putting my money where my mouth is, as my next mount will likely be a Paramount Taurus.
Being able to image uninterrupted to and through the zenith is something I should have done years ago. :doh:

[FrancoRodriguez]

Colin, well it looks like ASA still is making DDM85's. I'm pretty sure I'll get the standard model. That's got 65kg payload capacity. I'd love to chat to you some time about getting it up and running. Have you had to send it back for any reason? I was told today by the Australian distributor that there are people in Australia that can fix them so no need to send all the way back to Austria. True?
Thanks once again,
Franco

[FrancoRodriguez]

woah, a paramount taurus is quite a piece of gear! Never seen one in real life. You'll need Arnie guns to get it onto the pier, or a couple of hefty guys. You'll need a field derotator too right?

[Peter Ward]

It's an equatorial fork. No de-rotator required. Lifting a RC16 on to a GEM is actually harder. Been there, done that, got the T-shirt ;)

[markas]

Francisco,


I'm currently running a DDM85 standard (NOT Basic) with a 300mm f/8 RiDK and a G4-9000 camera - so it's 2400mm focal length, 1''/px, and relatively fast data acquisition (~33% faster than 16803 because of the 12micron pixels).



This is easily capable of doing the 10min subs I need for narrow band and the 5min RGB is a no-brainer. FWHM analyses of my subs is always seeing limited, which at my site runs between 1.8" and 3".



It isn't only a question of encoders, but the software and direct drive motors together and how the system tracking is achieved. The pre-imaging track correction system of the ASA package (MLPT) has no equal that I'm aware of.


I also own a DDM60. When I was getting used to it, I ran a tracking test (scope was a 900mm focal length Newtonian). I shot 12 x 5min subs without dither, and analysed them in Pixinsight. The reported maximum drift over the hour was 0.6px ie <1''.


Regarding ASA, they are moving heavily into the professional market, as is Officina Stellare. I always had very good response from ASA when I ran into problems with the DDM60. But I think the 85 is a far more "bullet proof" unit, and I've never had any grief with it at all.


If you are running a 12.5" or 14" CDK I would not expect you to have any problems, at least up to the 10min sub time.



The ASA system is a unique beast, and the learning curve is quite different. Balance, for example is super-critical, regardless of the load, and motor tuning is also important.


I have no experience running remotely with my set-ups, so I can't comment on that. However, there are others who regularly do this.


Hope this helps with your decisions.


Mark

[FrancoRodriguez]

Thanks for your thoughts. I have bitten the bullet and bought the ASA DDM85. The idea of direct drive plus renishaw encoders really couldn't be beaten. I hope it lives up to the hype. Thanks again everyone for your kind help and assistance

[FrancoRodriguez]

I can't remember if I thanked you personally but I'm very grateful. I'm getting the standard version too. Would you mind if I occasionally ask you a question or two once it's ready for setup? I promise not to badger you with millions of questions!

[Atmos]

They’re definitely a mount that you have to get used to but once you get used to them and their idiosyncrasies they’re fantastic!
For a while at first I would on some nights get random errors that left me with worries that stopped the mount but it would describe what the error was. Looking back on it now, I’m pretty sure that it was me not being anal enough about balance. During a dither command the amperage could get a little high for that small move and it would cause a error which resulted in a loss of location for the encoders.

This would happen on some nights and no others and it would happen at random times. What was likely happening is that some nights I was balancing better than others and some dither movements were more demanding than others. I now spend sometimes that every 5 minutes getting balance as good as possible and I haven’t had those issues for a long time.

Being a direct drive it isn’t as simple as a geared system but it is best in class. If I was to get a bigger mount I’d get another ASA so I think you’ve made a good choose there.

[alocky]

I only just saw this thread. I’ve been using the DDM85XL in my observatory for a few years. When I got it, it did require a trip back to Austria for repairs and I can honestly say the support from ASA was excellent- I wouldn’t waste my time with the local distributor.
My experience is at odds to Peters with respect to unguided imaging. Using the mlpt process has produced tighter stars than autoguiding, but the skies over Perth has a different set of challenges, and we are usually seeing limited.
Happy to talk more - pm me, but it sounds like you’re already committed!
Cheers
Andrew.

[Astromelb]

Dear IIS team,

Thank you for all your comments and assistance to Francisco in making his purchase decision.

Although I have a modus operandi of being very reluctant to comment on threads on IIS, there are a couple of items here that may benefit from some clarification.

1. The ASA DDM 85 is still in production, I have made an offer to yet another customer for this product this week
2. Thank you to Peter Ward for your comment. As your business is the Paramount (& Astro Physics) distributor for Australia you should without question be supporting and preferencing your own product. Your positive commentary re your own businesses portfolio may be better placed on threads that refer to this Paramount product ? This thread refers to 10Micron & ASA DDM, let's stay on subject ?
3. Thank you for Andrew Lockwood for your comments. To explain - Andrew purchased a used 2nd hand ASA DDM85XL from a private seller in Queensland. This was a private sale and did not include input until supply was completed by either myself as ASA Australian distributor - or the OEM manufacturer, ASA Astrosysteme. The mount was subsequently found by the buyer to have significant needs for spare parts and rectification matters. Although as ASA Australian distributor I am available for assistance, Andrew as purchaser made direct contact with the ASA Service Department regarding these servicing & replacement parts requirements. I found out all about what transpired in detail at a later date. Andrew’s comment of going "direct" to ASA on his servicing & parts requisites is quite understandable. It is noted that he and I did not have dealings regarding this project, so his comment saying "go direct" refers to a service & spare parts application on a 2nd hand used mount. We did not have dealings together, so I have no experience in supporting his project.

New ASA products are not available direct, please refer to the appropriate contact method to enquire with my business as Australian distributor, you will all know how to find my business, as this is not a sales & marketing thread.

Finally for Francisco - we all look forward to your project coming together and your system providing you with many years of outstanding service. As a customer you have been a delight to deal with and I am delighted to have been of service to you with your project.

Thanking you.
Rgds,
Cris Ellis,
Astronomy Alive.

[Peter Ward]

I appreciate the post was referring to 10Micron and ASA, but my input here was not wearing a commercial hat.

I've been doing AP for a while (actually, about 4 decades) and have picked up the last 3 DM deep-sky awards in a row..
(plus have over 70 National and International astrophotographic awards)

So, perhaps I am qualified to comment without you pulling what comes across to me as a shallow "commercial interest only" card?

At the risk of harping on, my experience has been unless you have a closed feedback loop to ANY mount...including ASA, AP, Bisque etc.etc. you simply will not obtain consistent results, without looking at a guide star.

The physics is pretty simple, you cannot compensate for what the atmosphere is doing only by having a near-enough perfect RA drive rate (which, to be sure, is a good starting point).

P.S.
My intention was not to promote one product over another, but to say
I think if one hopes to avoid guiding and still obtain truly high resolution deep images
you are in for a disappointment....at least until cameras that allow "lucky" deep sky imaging become available.

[alocky]

Yes, it is true we did not correspond about this particular mount, and I'll leave it up to the previous owner to comment on what role you played, if any (I have no idea), in the unsuccessful attempt to get it to work as a new purchase in his observatory in QLD, which ultimately resulted in him giving it up and selling it at a very reasonable price to someone willing to take a risk on what was most likely a defective product to begin with.
Unless the purchaser is local to your business (and over here in WA I might as well be in Austria) I doubt there's much you can realistically add to the support from ASA and there was no intention in my post to cast your business in a poor light.
However, ASA are perfectly willing to sell direct to anybody. I spent considerably more money with them on the OTA that sits on my mount. Adding an extra step in the procurement chain that doesn't add any material value will only increase the cost to the consumer. For a customer in Melbourne who is completely new to high-end astronomical equipment, I'm sure you provide a very valuable service, but to me, I'm afraid, you are unlikely to add any value.
Although it seems fun to bash Peter at the moment, I can't help thinking that someone who can turn out images consistently of the quality he does has a right to express an opinion on anything astrophotographical without his ethics being called into question. I suspect the 'business' he runs is more of a service to Australian amateurs, since he most clearly does not need the money. In all the years I've been in this forum I have never heard a negative word about the service his company provides, which is certainly something very few retailers can boast.

Anyway - very happy with my ASA, but wish I could get results on a par with Peter. Or Mike, or Paul, or Mike and Trish, or any of the people that consistently publish superb images on this site.

[Astromelb]

Thank you for your comments.
1. Mr Peter Ward - you are most welcome to your opinion. Others on this forum have a different experience. Your experience is with mounts that need guiding, and this is absolutely fine. Your images are most capable, but you do need to guide them.
Those that use ASA DDM do not guide for their imaging processes, and have a different experience, and they do not share your opinions.
Let's merely leave it at that.
This should not turn into another heated supplier bashing thread (exactly the reason why I stated that I usually steer clear of this webpage as it regularly ends up in this situation, this webpage has a very bad reputation for that).
2. Mr Andrew Lockwood - thank you for your clarification. Let’s make sure we get your project details correct.
Your observatory is located in regional northern WA. It runs a large ASA Newtonian astrograph, you purchased this astrograph before Astronomy Alive was engaged as Australian distributor for ASA Astrosysteme. You purchased this telescope direct from ASA as at that time they sold direct into Australia.
You then subsequently purchased this used mount 2nd hand from a private seller in Queensland.
This mount has a nominated 100Kg capacity - the gear that was placed on it was not 100Kg, it was in excess of this mass.
Although I know the full story on this project - commercial confidence between myself and my original buyer is in place, so I will not comment further.
If the original owner discussed issues with you this is between the two of you.
After you had purchased and received the goods and found issues, ASA contacted me and referred your issues to myself. I decided that since you had not purchased the mount from myself and had been dealing with ASA direct for your ASA Newtonian – then for this special case - I approved them to sell the spares & repair parts direct.
The mount needed significant works, servicing and replacement parts. I respect you purchased (it seems without knowledge of any concerns ?) a unit that needed a works and money spent on it to return it to operational capability. You are aggrieved via same. I would be too. My apologies for this situation, I feel for you. However this matter is a commercial issue between you and the seller. What happens to a product following supply to any customer is the responsibility of the customer, not the manufacturer or their distributor.

[Peter Ward]

There was in interesting hearing in the ACCC a while back. It involved York Optical and a Meade telescope customer. Meade made some claims in their advertising back then that did not stack up under Australia consumer law. York simply parroted Meade's claims in their advertising on-sold their product. As it turned out the Optics were not the finest available and their computer pointing and drive systems were unreliable. The luckless customer was not getting any joy from York or Meade, so after many months hauled York into a ACCC hearing. The result?

York were not only required to take back the telescope but to refund the full purchase price, including shipping WITH interest.

As a retailer of Astronomical products, I took some serious interest in this result.

So, my point. I'l like to avoid guiding. Are you prepared to sell me an ASA mount (one that can hold about 60kg of payload) on the basis I can have a full refund, including shipping costs, if it does not deliver perfectly round stars at 3400mm and 20 minute sub exposures? (Which is what I do now)

[Atmos]

I think one of the big parts of what Peter has been trying to get across can be summarised in the quote above and I tend to agree. I’ve had my Mewlon 250 out for imaging one night so far and I know I was seeing limited as it wasn’t good enough to potentially fine tune my collimation and 1s focusing exposures couldn’t get good FWHM either.

What Peter is getting at in concept is that although my DDM60 can track accurately it isn’t compensating for atmospheric movement. A number of years ago SBIG wrote a report on consumer level adaptive optics (AOX, AO8) that showed it cannot do anything about the fast moving millisecond seeing but that it can help with improving FWHM due to correcting for the slow moving convection cells in the atmosphere which have a scale of <1-2s.

Under poor seeing there is likely nothing that can be done but as the seeing overall improves consumer level adaptive optics does have the potential to help correct for some slow moving convection cells on some nights. From memory these tests weren’t done at altitude so I’d imagine that adaptive optics units would have more of an improvement under good seeing at sea level than the same seeing at altitude.

[alocky]

The previous owner was unaware of the extent of the issues with the mount and was quite open and honest about the performance of it. The fact is, this mount had it not been supplied defective could have managed to carry his OTA as this version (XL) is significantly reinforced in the right places. I do know that he did buy it through you, and you were listed as the sole Australian agent for ASA for many years prior to these events. As such it’s more than a little disingenuous of you to suggest that he misrepresented the condition of the mount to me and is somehow responsible for its condition. I hold no ill will in that regard whatsoever, but this highlights the value of recognising to the original poster that if the mount arrives and does not perform as expected, he will largely be on his own when it comes to getting anything fixed, because there is nobody in Australia qualified to service or repair these mounts.
Regards
Andrew.

[Astromelb]

Mr Lockwood,
I am most sorry you have had this experience.
The original mount was supplied to the original owner (buyer) and he used it for quite some period capably without announcing operational concerns.
Further questions regarding the original owner and questions subsequently asked regarding the system (the full system not merely the mount) were reviewed between him & myself, but are between the buyer and my business. If you have any questions these are unable to be assisted from my end. If you need extra information these should be addressed to the party who sold you the unit.
It would appear that you may be saying that the unit never worked for the original owner - this is not his feedback to myself - I am able to confirm that this is not the case.
I am sorry you are so upset, but your arrangements with the seller are between you two - claiming that my business is responsible and that the unit never worked is unfortunately incorrect.
As stated these threads seem to nearly always go off the rails. You purchased a product and have occasioned issues, again I am sorry this has happened for you. As original equipment supplier once the gear is supplied and installed and is operational the responsibility for the system condition and care passes to the owner.
As stated I am sorry you have had this subsequent experience.

[alocky]

I’m not in the least bit upset, and I am not trying to cast aspersions. I got the mount knowing it had problems for a reasonable price. It did cost a bit more than I expected to return it to service - but my point in this thread is - if you need repair work done on these mounts it will need to go back to Austria.
This will cost quite a bit in shipping and time. I have nothing but praise for ASA, they handled the shipping, fixed the mount, and gave me a heavily discounted price for repairs because of the history of trying to get this particular mount to perform remotely. Very positive experience with absolutely no relevance to you or your business and I have a mount that delivers .1” rms tracking for 10 minute subs and handles a 60kg payload effortlessly. It will not track that well for 20 minutes, though - Peter is quite correct in that regard but adding an autoguider to the mix is pretty simple.
This thread is not about you or your business- it is about ASA and 10 micron mounts. I suspect there’s also nobody in Australia who could repair a 10 micron either.
I would cheerfully buy more stuff from ASA, and I would also do it direct. They respond promptly and efficiently to warranty and repair items that would take too long if a third party was involved.
Regards
Andrew.

[Astromelb]

Mr Andrew Lockwood,
May I recommend this thread is about Francisco's project.
As a final note:
The original buyer of your mount provided myself with - and also posted a number of - images taken with his system after installation & commissioning.
Some of these images were posted on IIS and are most capable.
These images demonstrate the system performed to it's design and spec. You seem to be trying to claim the system was incapable from receival by the original owner, this is incorrect. He had a learning curve, as we all do for every piece of exotica level astronomy gear we procure, but his images are evidence the system performed to design intent.

There is always much to learn about for us all in astroimaging, none of us knows everything (some on IIS try to think so though. Lol) and we are all always learning the craft as we progress. This is always a journey.
I am aware that the original buyer had more learning to do, as we all always do. But he on sold the unit - and thereby the journey for this particular mount then passed on to you.

Back when you purchased this as a used 2nd hand mount - I took the proactive step to contact you and offer assistance. This was not as a commercial endeavour, it was simply and merely to help. My experience and knowledge of the system and much of its history I knew was of significant value to you. I was merely doing this to hold out the hand of assistance, to help.
You declined.
You actually were quite blunt and told me you did “NOT” need my assistance.
If you have any further questions for me regarding this system you are welcome to email me. You know how to contact me.

For your information ASA products are available from their distributor network, for our region Astronomy Alive. Only spare parts are available direct by the way (if approved via the local distributor).
I will not be commenting further on this thread.

[alocky]

Now you are telling untruths. You did not contact me at all, and I refer to your first response in this thread where you stated you were unaware of the entire series of events until much later. You have aggressively pursued a narrative in this thread that is not supported factually and I had no wish to involve you in any of my responses, but you insisted in making this about you.
As far as I know neither you or any representative of your company had anything to do with either identifying or rectifying any of the problems in that particular mount, and fortunately as Peter has already highlighted, there are certain consumer protections in our country that protect us from defects in new equipment, so it’s fair to say you did not supply a faulty mount to the previous owner or you would have certainly replaced or repaired it.
As it is, your behaviour in this thread should give any prospective purchaser a very good preview of the after sales service that can be expected, so I hope you are comfortable with the impression you’ve made.

[sharpiel]

Off topic perhaps...now the thread has evolved...maybe not.

Chris (Astromelb) I'd certainly have avoided you in the past and will do so in future for any astronomical purchases or advice...

[FrancoRodriguez]

Hi everyone, well that escalated quickly! I didn't want to start a flame war. All I can say is that Cris from Astronomy Alive has acted in a very professional manner with me. He did a lot of research regarding exact pricing, was punctual and responded to my queries very quickly.

[FrancoRodriguez]

Hi Cris, I just wanted everyone to know that I have so far had a very positive experience with you and your company Astronomy Alive. There's clearly something going on with rival importers and companies--I'm going to avoid it all like the plague. I'm looking forward to getting my new mount. It's going to be excellent! Very excited....

[Atmos]

You will be very happy with your purchase, it does take a bit to get used to but once you have everything dialed in it’ll be a fantastic performer. I am curious about how far I can push my Mewlon 250 at 0.4”/pixel on a calm night with reasonable seeing. I am still thinking about installing an OAG if for nothing other than “insurance” on the 30 minute exposures.

[FrancoRodriguez]

I don't see how using an OAG could possibly be a bad thing. It's great to have a mount that moves extremely precisely but it's no biggie if it occasionally needs a little nudge here or there. What are your thoughts on 'active' (not really adaptive) optics? Do they alter the main image or the guider image?

[Atmos]

The consumer adaptive optics offered by SBIG (Diffraction Limited) and Starlight Xpress is like an OAG but does most of its movements without the mount requiring movements.

There is two lines of thought:
1) They’re only useful for small fast guide corrections to correct for the machining of geared mounts.
2) They can be used for 1) and help with slow atmospheric turbulence. Not the sub millisecond stuff that true adaptive optics works with but slower star movements.

I have no doubt that my DDM60 can create an accurate model for long unguided exposures and keep the star centred on a single pixel at longer focal lengths BUT what it cannot do is correct for atmospheric turbulence.

I can get round stars without guiding but I do not doubt that if I was to use an adaptive optics system that my stars would be sharper because it would be doing the tiny movements to keep the star centroid central as opposed to the atmosphere moving it around quite so much.

[Slawomir]

Congratulations Francisco - we look forward to reading your impressions with the new mount. Very exciting news!

On the topic of Active Optics, assuming perfect tracking and negligible flex in the telescope, I’m curious whether Active Optics help to tighten stars across the entire sensor, especially when combined with a larger aperture telescope and a large sensor, since prism corrections are made for a star that is outside of the light beam hitting the sensor.

To put it more clearly - it would be good to know an approximate size of the circle that benefits from Active Optics around the star that is being measured and corrected for atmospheric turbulences.

[Atmos]

I guess it would largely depend on the FOV but I'd imagine that it wouldn't make that much of a difference for most applications that us amateurs are doing.
Most of the convection bubbles that an AO unit MIGHT be able to help with are several KM across but they're also far away. Would it help a FSQ with 4º FOV? Yes; but due to the under sampling it would only help with mount tracking errors.

Take a 10" F/4 Newtonian and ASI1600 setup, it has about 1º FOV and a guide star would be only a fraction wider than that. The AO unit is doing sub pixel movements over a relatively small and "slow" (0.5-2s) moving air mass that causes refraction, running a 3Hz you should be able to semi accurately model the movements. It is true that one side of the field will be different to the other as convection currents run both up and down depending on whether they're carrying warmer or cooler air but the law of averages say that it should show some improvement :)

I cannot quite remember the figures used in the original document I read but you'd only be looking at improvements of 1.8" to 1.7" or at a stretch 1.6" depending on what the atmosphere is doing at the time. Under generally poor seeing (strong jet stream) AO doesn't do much as it's a fast moving issue (need millisecond corrections at the wavefront).

My own theory is that it would work better for those of us at sea level where we have more atmosphere that we're imaging through and on nights of better seeing.