First tests with dual Askar 120 APO rig

[fwm891]

I have my two Askar 120 APO's on a temporary plywood non adjustable base at present really just to make sure this set-up is going to work the way I had it working "in mind's eye" to start with. (Must take some photo!s)

I have a pulsar pier with an iOptron CEM 60 on top (non EC) in a RoR back garden obsy with quite restricted skies due to buildings and trees. Long ago I had a 115 refractor which I sold and regreted selling as it walked out the door. Recently I've had problems handling my 10 newt on and off the mount so I decided to get another refractor and purchased an Askar 120APO. After 1st light with this scope I put in an order for a second, what a brilliant scope and started drawing up plans to build a platform for the pair to get them looking at the same patch of sky. Needless to say N°2 arrived before I'd built the adjustable platform so a piece of 12mm marine ply had to take it's place. I very carefully machined and planed the plywood to make it fit for purpose as possible and bolted the two tube ring assemblies on one side and a losmany plate on the other. All as parallel as I could make them.

The tube assemblies I've offset lengthwise (35mm) so the focus knobs don't clash. Dec balance was done by shifting each OTA by the same small amount until they could be left without tipping up or down and locked off. Cameras were mounted and cables attached. I was surprised I still only needed the single 9.5Kg counterweight supplied with the CEM 60 although it was right out to the full extent. I added a small 1Kg weight to bring the bigger weight in a little and use the smalller weight's movement to fine tune RA balance. The OTA's both have 1x flatteners and I have a 0.8x flattener/reducer which is the same weight as the 1x so balance should be little effected by a change over.

The cameras in use at present are an ASI 2600MC DUO and a 585MC I'm yet to work out how to get both cameras working via NINA so I'm using NINA to control the DUO/mount/guiding/dither etc as normal and ASI STUDIO to just capture images from the 585. Loosing the odd sub where dither happens during a 585's sub...

As  it's galaxy season here's a couple of 'pairs' from Friday night with this set-up as it is at present:

Edited April 1 by fwm891
Photos added

[astrosathya]

Brilliant photos Francis. Would love to see pictures of your rig.

 

[Stuart1971]

Sounds great and nice set of images.

AFAIK you can’t run two imaging cameras from one instance of NINA, you have to open a second instance and do it that way, but the second instance only needs the camera connected and nothing else…👍🏻

[Mark at Beaufort]

Lovely Astro photos Francis. I was a bit surprised that you bought two Askar 120mm telescopes but I can see now why you bought them.

[Stu]

Wow, beautiful images Francis. Photos of the rig please!! 👍👍

[fwm891]

Photos added as requested 👍

[dweller25]

Wow, great setup and superb photos 👍

[fwm891]

Last night was the first clear night for what seems ages so I tried some imaging with the 120 rig and an ASI 585 MC (uncooled) camera on a couple of deep sky objects (M51 and M106) I kept to more common objects as they're well known making the outcome easier to judge too.

The 120 APO had it's 1x flattener fitted so working at f7. The 585 had its gain set to 252 with an offset of 25? (need the check that). UV/IR cut filter used for all exposures.

M106 13x 180 second subs. Processed in PI. Stars and background processed separately then brought back together with pixelmath I also experimented with a soft mask to help control the background/foreground balance.

M51 22x120 second subs. Processing similar to M106.

Both images reduced for display but uncropped.

Edited April 10 by fwm891

[dweller25]

Really nice images 👍