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Veloce 200RH on DDM60 first light


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#1 lukepower

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Posted 08 August 2016 - 05:57 PM

Hi guys,

after a few days of work (I was luckily only involved on the software side, remotely doing that) we got our Veloce 200RH set up in Nerpio, Spain.

 

After a few iterations polar alignment was done:

Attached File  935cc8fa-d757-4d54-8457-107b1620d673.jpg   26.3KB   8 downloads

 

Shortly after we got down to a quick 10 minute exposure. Mind you, we used no pointing file at all:

Attached File  WhatsApp Image 2016-08-08 at 03.07.04.jpeg   134.89KB   6 downloads

 

I will go and try to get some more data tonight. This system is impressive, it seems that we do not have to refocus most of the time (only after a temperature drop of 20°C)...

:)


Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#2 Waldemar

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Posted 08 August 2016 - 08:56 PM

That is quite a nice scope... and deserves it's name with f3...

Keep us updated Lukas.

 

Waldemar


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Mount: DDM85 Standard 12V ; Telescopes: TEC140 + 140FF + Quad TCC ; Celestron RASA; TMB 92SS + 27TVPH Cameras: ZWO ASI 174MM cool; SBIG STF8300M; ATIK4120EX; TRIUS SX-36
Filters: Astronomik and Baader NB + RGB; Lunt double stack 75 mm unobstructed signature series + BF 3400; Dutch weather and light polluted skies.  

#3 lukepower

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Posted 09 August 2016 - 07:11 AM

Hi Waldemar,

yes it is indeed very fast. Funnily I did a big pointing model last night which failed to track accurately - no model is better than a real model, it seems.

I will have to narrow it down the next nights. We also have some problems with the focus as the critical focus zone is VERY small. The guys at Officina Stellare upgraded the scope recently and they still have to work a bit on the software, but basically we can remotely adjust the tip/tilt of the system, which is awesome considering how crucial the system is in that regard.


Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#4 Waldemar

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Posted 09 August 2016 - 08:48 AM

I have a RASA with f 2,2 so I know how critical focusing is, with those fast scopes...the lightcone is very steep, I use Starizona's MicroTouch system for it. That works pretty good. With the new software you can set it on 1 step per click. 300 steps on 1 turn of the fine focus knob of the FeatherTouch focusser.  And even that is critical...

But your Veloce has it's own focussing system I've seen.

I found too that pointing models very much depend on the seeing conditions. Although where your scvope is situated it should be pretty good, I guess...

You can remotely adjust the tip/tilt sytem of the mount??

I must say the tip/tilt system is not my favorite... I made an azimuthal adjustment plate for it. I know it does not make any real difference, but still...

I understand that ASA kind of came back from it too, when looking at the Revolution. But when and if that will ever be taken into production???

 

But no doubt you will make great images with that scope!

 

Waldemar


Waldemar
--------------
Mount: DDM85 Standard 12V ; Telescopes: TEC140 + 140FF + Quad TCC ; Celestron RASA; TMB 92SS + 27TVPH Cameras: ZWO ASI 174MM cool; SBIG STF8300M; ATIK4120EX; TRIUS SX-36
Filters: Astronomik and Baader NB + RGB; Lunt double stack 75 mm unobstructed signature series + BF 3400; Dutch weather and light polluted skies.  

#5 lukepower

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Posted 09 August 2016 - 09:11 AM

Hi Waldemar,

 

well the critical focus zone is only 6 myu wide... Actually the tip-tilt system is for the orthogonality between the camera and the scope, and it works quite well.

The focuser has extremely fine steps, but we still have to sort out a few things there (mostly software stuff). The scope itself is the "RH" version, which should need no refocusing in a very wide range of temperatures, so that too needs to be checked as it is still not working completely as we'd expect it to do...

 

And yes I agree that the tip/tilt system of the mount is crap - way better the way the DDM85 is doing that.


Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#6 lukepower

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Posted 12 August 2016 - 07:09 AM

Hi guys,

after some testing the unthinkable happened  :blink:

 

We created a really big pointing file with Sequence, but after loading it we had trailed stars. We tried to disable SuperFit to no avail, soas a last resort we unloaded the whole pointing file. And this is the result (10 minute exposure, cropped):

Attached File  Screenshot_2.jpg   85.38KB   5 downloads

 

So what do we learn? Sometimes the pointing models are more bad than good...

 


Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#7 maxmirot

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Posted 13 August 2016 - 04:53 PM

Interesting looking thin rings like halos on the stars.

 

What vesion of  Autoslew are you using?

 

Max



#8 lukepower

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Posted 13 August 2016 - 05:04 PM

it's 5.2.2.2

 

The thin halos you see are caused by something in the tube built, Officina Stellare is investigating that. Might be the new baffle design (this scope is sort of a beta test of a new one)...


Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#9 MarkS

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Posted 14 August 2016 - 12:56 AM

Lukas,

 

Interested in your comments on focus. I have found that the Sequence AF routine does not seem to be accurate enough at f/2.8 on the ASA10N/OK3.  I am currently using manual focus, which, with a temperature drop of ~10C over 4 hours, needs no adjustment.

 

As for trailing stars, I've never been keen on large pointing files. Sometimes I make a 10-15 star file if there is time available between PA and session start, but usually I just go with the last 3 star same DEC file obtained in the PA process, and use MLPT. I find this very reliable.

 

Mark



#10 lukepower

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Posted 14 August 2016 - 07:09 AM

Hi Mark,

we had our first full night of observations with the Veloce 200 AT yesterday. Basically, we are not using MLPT or a pointing model - simply a very well polar aligned mount. As for the focus issue, it looks like there are tube currents in the evening which cause some focus fluctuations, but we did not focus at all during the night. Combined with no guiding and no MLPT, we are basically imaging 58 minutes par hour (the rest being slew times and settle times). Damn this is one hell of a combination  :)

 

As for the pointing model issue, I will do a test with my Cassegrain, first by getting it better polar aligned, and then using a very small pointing model (like 15 stars or so) and see what that brings. 


Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#11 Jay

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Posted 25 August 2016 - 11:19 AM

Hi Lukas,

 

And congratulations for your new scope. It's a wonderful piece of equipment ...I know because have owned one for couple of years now  :)  Mine is not the AT model, so there is a need to do refocusing every now and then but no complains. 

 

It's a quite fast scope and the focusing a bit critical but I've been using the "Lunatico" stepper motor, Seletek and FocusMax, and have never had problems with the focusing. The focuser itself is the original from OS. I'm using a similar combination (stepper motor, Seletek, FocusMax) with my 300 mm Canon (F 2.8) and no focusing problems there either.  

 

Jay






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