AG Optical 12.5 iDK arrives

[loc46south]

In April of this year I placed an order with Dave Tandy of AG Optical for an iDK 12.5 Imaging Dall Kirkham Telescope. In late November this telescope was shipped to Christchurch where I picked it up from. It has now been installed and I have started to get it ready for imaging in the coming Autumn.

Originally the telescope was ordered with the new Optec Gemini Focuser but due to some issues this was not supplied, I have currently fitted it with a Moonlite CSL 2.5 but will replace this in the near future with a FLI Atlas.

The unit arrived crated in a wooden crate - it was well wrapped in bubble wrap and all cavities in the crate were packed with bubble wrap. It arrived safe and sound - there was no damage to either the crate or the telescope.

Build quality of the telescope is good, it comes with covers for the secondary mirror and the baffle tube plus there is an approx 5mm thick split plastic cover that screws over the primary mirror cavity.

I ordered the TCS System that controls the fans and the heaters fitted to the telescope. I did have problems trying to install the software on a laptop running Windows 8.1 but found that it installed no trouble on the Observatory computer running Windows 7 Pro.

At this point I have taken a few test images through the telescope and is is showing some sign of coma, it is obviously in need of some collimation tweaks - first light image will probably be after Christmas when the nights get a bit longer.

Cheers
Geof Wingham

[gregbradley]

Fantastic Geoffrey.

It looks great. Looking forward to your first light image with it.

What camera are you using with it?

Greg.

[Somnium]

Looking good Geof , +1 to Greg's comment

[RickS]

Nice looking scope. I'm also looking forward to the first light.

Cheers,
Rick.

[gregbradley]

You also can't go wrong with a FLI Atlas focuser. Its expensive but wow, what a beautifully made and functional piece of astro gear.

Greg.

[loc46south]

Thanks - I'm looking forward to first light too - but unfortunately it is some time away - the image train is far too heavy for the Moonlite Focuser for reliable imaging.

The camera I am using is a SBIG ST10XME - I deliberately chose the 12.5 over the 14 inch because at f6.7 it gives a usable field with the ST10 without a focal reducer. I know its not one of the half acre cameras available and is almost obsolete but I really like its performance with the tighter (3nm) narrowband filters, plus it suits the type of imaging I want to do.

Coupled to that is an AO-8 and an Innovations Foresight On Axis Guider - the guider is shown fitted with the remote guide head but that has proved next to useless - I have however managed to acquire a ST7XME and will use that as a guide camera because of it's sensitivity to NIR and it's ability to drive the AO-8.

All of course untested and waiting for a new focuser - perhaps Father Christmas will be kind this year.

Cheers
Geof Wingham

[Slawomir]

That's a beautiful telescope - I am also looking forward to seeing your first images taken with it.

[batema]

Fantastic looking scope. Enjoy.

Mark

[DJT]

Slightly envious.thats a gorgeous looking scope.

Was also lookin at Optec and FLI as part of next setup. What was the thing that changed your approach? Costing for both FLI and Optec ( I assume the Gemini version) seems quite close.

Enjoy the new toy.

[loc46south]

Thank you all for the compliments.

Simply put, the gruntiest focuser I could get from Moonlight was the CXL3.6 and it was rated at 10lbs load. Ron told me personally that the Crayford type focusers were not really suited to the heavier astrophotography loads. Because of the design the focuser tube acts as a lever causing the tube to bind. So the only focusers that could handle the weight are the Atlas and the Gemini.

The next problem was backfocus - the Crayford chews up 4 inches, the Fli Atlas 1.25 inches and the Optec Gemini 2.5 inches. (the Gemini does include a rotator) Once you start putting your image train together back focus disappears like magic. The cost difference between the Atlas and the Gemini is USD$1,100

The biggest problem seems to be availability - I ordered the Optec Gemini from AG Optical in April 2015 when I placed the order for the telescope - it wasn't available when the telescope shipped in early November. Which left only the Atlas - which was one reason I went with the image train I am using.

The Atlas removes the weight restriction and the Innovation Foresight On Axis Guider removes the absolute need for the OAG and a rotator to find guide stars. By using the ST7 as a guide camera means I can use the AO-8 and still have room in the future to fit a Reducer should the need arise.

Help :eyepop:- what started with a C9.25 and a hand me down Mead DSI has mushroomed somewhat.


Cheers
Geof Wingham

[George Ionas]

Geoff,

Can't wait to see your first light images, looks like a nice setup.

George

[loc46south]

Thanks George - So far there have been no disappointments, I'm working on getting the computer and the power supplies for the cameras setup, you will have to ignore the "spaghetti" - that will all disappear eventually.

I need some longer nights to do some more setup work and there is still a little bit of coma left in the system but we will get there. There is still a lot of testing to do but hopefully some sort of image in the new year.

Cheers
Geof Wingham

[Octane]

Go the little G-11! :)

Congratulations, on what looks to be a beautiful scope.

I spent several nights drooling over them while looking at them on the web site.

H

[loc46south]

Thanks Octane - I'm rather attached to both my G-11's, I've had them for over 10 years, I know they are obsolete, but then so am I. They have never let me down. This was the main reason I went with the 12.5 iDK instead of the 14inch - it let me keep all my existing gear.

The telescope is good and the more I get to grips with it the better it is getting. I spent last night working on the collimation and we are just about there. Attached is the CCD Inspector report and the image analysis. Also attached is a 10sec exposure bin 2x2. It shows good contrast and a nice flat image. It also shows dust donuts - it was taken at 11.30pm and there was still a fair bit of residual sky light. Things can only get better

Cheers
Geof Wingham

[gregbradley]

That looks great.

By the way I don't recall ever not finding a guide star with my CDK17 and MMOAG with SBIG STi guider. Occasionally I have to move the image off centre a tad to get one.

Greg.

[loc46south]

Hi Greg - I suspect you are referring to the Innovations Foresight On Axis Guider. I'm a bit if a sucker for new technology - I like the idea of it and I am going to couple it up to a ST7XME so I can drive an AO-8 off it. I also like the idea of the Focus Lock software being able to adjust your focus in real time. Time will tell if it is groundbreaking technology or just another item for the back shelf in the garage. For me it does away with the rotator and saves a few inches in back focus.

Cheers
Geof Wingham

[gregbradley]

No I was referring to your comment about the rotator making it easier to get a guide star. It probably does just that without one I have not had much trouble getting a guide star.

Also using a reducer on the guide cam helps getting guide stars as well.
Scope stuff sells them, GSO reducers I think they are .5 or .6X.
Greg.

[Peter.M]

He is guiding on axis, so a rotator will not assist in finding a star. I believe the problems he was experiencing were due to the remote head having low sensitivity in NIR

[alocky]

That's far better guiding with the G11 than I'm getting at half the focal length! Nice work! Does your G11 have an Ovision worm or any similar upgrade?
I'm also looking forward to seeing what you get from this system.
cheers,
Andrew.

[loc46south]

Greg - Peter is correct - I suspect that the Remote Guide Head has a NIR coated chamber window, not that it matters now - I have sourced a ST7XME and that has a QE of around 50% at 850nm, so guidestars will not be a problem.

Alocky - The G-11 is a great little mount - The one with the iDK does have an Ovision worm and Pempro gives a PEC of 1.97 peak to peak. One thing I have found is that the G-11 does not respond well to a fast guide cycle - I usually use from 3 sec to 12 sec depending on conditions. That image was however unguided.

I also share you apprehension, I have waited a long time to get my hands on a telescope as good as this.

Cheers
Geof Wingham

[gregbradley]

[QUOTE=loc46south;1217399]Greg - Peter is correct - I suspect that the Remote Guide Head has a NIR coated chamber window, not that it matters now - I have sourced a ST7XME and that has a QE of around 50% at 850nm, so guidestars will not be a problem.


That's interesting, so the STi has a NIR coating. That may well be true. It would explain why I didn't see much of a gain using an IR filter on a MMOAG with it.

Greg.

[PRejto]

Geof,

The ONAG is a great piece of kit...just be quite sure about your back focus and equipment clearance.....and, if you mount the imaging camera close to the ONAG you must make sure that the guide camera will come to focus! The ONAG does provide a good FOV but only as wide as the camera guiding unless you move the stage which presents problems if you are remote (read that as cannot be done)....so, I am using an SX ultrastar to guide.

FocusLock works great! I was a beta testor for this software and I now use it for all imaging. My subs have never been better and the FWHM just stays constant...only drifting lower with altitude and never with temperature.

Peter

[gregbradley]

FocusLock works great! I was a beta testor for this software and I now use it for all imaging. My subs have never been better and the FWHM just stays constant...only drifting lower with altitude and never with temperature.

Peter[/QUOTE]

Peter,

Do you think the ONAG gives better results than an AO unit? You can combine both I assume but it would start to get pretty heavy and complex.

But focuslock plus improved guiding seems a good gain. I wonder if its the same or more than an AO?

Greg.

[loc46south]

Thanks for the heads up Peter on Focus Lock and the On Axis Guider - I intend to use it and it will fit the image train. Greg firstly the ST-i should show some image in NIR it is not fitted with a window, there is only a cover slip on the CCD.

Secondly I intend to experiment with AO-8, I have acquired a SBIG ST7XME as a guide camera and intend to use the main chip as a guide chip and it is capable of driving the AO-8. We will see over the coming months how it all turns out.

I still need to work through problems with the Focuser and replace that as the one I have will not adequately support the weight without flexing.

Cheers
Geof Wingham