128 replies to this topic

[Phil Jones]

Made it out to dark skies earlier this week, but had to dodge clouds. Attached the QHY 268M & CFW3 w/ a short 16mm nose w/ 48mm threads.

 

 

 

My QHY autoguider refused to track a guide star, so I did only 60 second exposures and hoped the Rainbow Astro RST-135E (E = encoders) could track unguided well enough for imaging. I shot 5 exp Ha and 4 exp RGB for each filter. So this HaRGB image of M42 is unguided, uncalibrated, and no flats....

 

 

First impressions:  I am very please with the AT60EDP. As I mentioned previously, the focuser is solid and the scope is built like a tank. Optically, it exceeded my expectations. Best $600 I have spent in a long while.

Edited by Phil Jones, 28 March 2025 - 11:44 PM.

[norcalryder]

Hey Mark,

 

The available backspace for the 60EDP is 55mm since the focal point lies beyond the end of the draw tube.  However, that is calculated from the m48 threads at the back of the retracted drawtube not the extended.  Here is a diagram of the Sky Rover version of this scope:

IMG_3112.png
 

According to the specs that I had gathered regarding your optical train, here are my calculations:

21mm     - m48 filter drawer
21mm      - m42 to m42 adapter
17.5mm  - 2600mc backspace
59.mm    Total

So 59.5mm  gets you slightly past the focal plane. I would recommend getting a narrower m42 coupling adapter. I would go no more than 10mm so that you are afforded some focus range, but the smaller the better (personally I would try to go 5mm (but no less as they can be a pain in the butt to remove).

 

Good luck

-karl

Thanks Karl - that diagram is just what I needed.  I bought the set of extension tubes Mark pointed out.  I'm mounting a Sony a7riii.  It has a flange focal length of 18mm.  The m48 e-mount adapter I got on ebay is 10mm so adding the 30mm extension should put me at 58mm whch is only 1.1mm in front of the focal plane.

 

18mm    e-mount Flange Focal Length

10mm    m48 e-mount adapter

30mm    m48 extension tube

58mm 

 

Thanks gentlemen!

[hfjacinto]

I had considered the Astrotech as it was super nice, but decided to go with a Stellarvue 70MM with the reducer it functions as F4.8. I also liked the risers.

 

I did change the focuser to a Motorized moonlite.

 

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[hfjacinto]

At F4.8 it lets you do the whole Veil.

 

 

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