Mounts: 10Micron versus ASA - Page 2

Atmos (Colin) · #21 05-08-2019, 10:40 AM

Quote:

Originally Posted by Peter Ward

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 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 (Andrew lockwood) · #22 05-08-2019, 10:42 AM

Quote:

Originally Posted by Astromelb

Thank you for your comments.
1.
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.

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 · #23 05-08-2019, 12:39 PM

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 (Andrew lockwood) · #24 05-08-2019, 01:07 PM

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.

Quote:

Originally Posted by 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.

Astromelb · #25 05-08-2019, 02:05 PM

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 (Andrew lockwood) · #26 05-08-2019, 02:22 PM

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.

Quote:

Originally Posted by 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.

sharpiel · #27 05-08-2019, 04:24 PM

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 (Franco) · #28 06-08-2019, 11:42 AM

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 (Franco) · #29 06-08-2019, 11:45 AM

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 (Colin) · #30 06-08-2019, 01:41 PM

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 (Franco) · #31 07-08-2019, 06:24 PM

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 (Colin) · #32 07-08-2019, 07:10 PM

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 (Suavi) · #33 08-08-2019, 06:07 AM

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 (Colin) · #34 08-08-2019, 09:16 AM

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.