M81 & M82 – First Light – (Rouz Astro Reducer-OAG Kit)

M81 & M82 – First Light – (Rouz Astro Reducer-OAG Kit)

JL1E2eMZt7xg 1824x0 rF2um8O2

Click on the Image to see Full Size


Imaging Cameras : QHYCCD QHY600PH M
Mounts : Astro-Physics 1100GTO
Filters : Astronomik Deep-Sky Red 50 mm · Chroma H-alpha 3nm Bandpass 50 mm · Chroma LoGlow Light Pollution 50 mm
Accessories : Optec Gemini Rotating Focuser · Planewave Reducer 0.66x CDK12.5-14-17 · Optec Sagitta OAG
Software : Pleiades Astrophoto PixInsight · Stefan Berg Nighttime Imaging ‘N’ Astronomy (N.I.N.A. / NINA)
Guiding Cameras : ZWO ASI174MM Mini

Acquisition details

Dates : May 26, 2022
Frames : Astronomik Deep-Sky Red 50 mm: 70×180″(3h 30′) (gain: 0.00)
Chroma H-alpha 3nm Bandpass 50 mm: 36×600″(6h)
Chroma LoGlow Light Pollution 50 mm: 60×180″(3h) (gain: 0.00)
Integration : 12h 30′
Avg. Moon age : 25.84 days
Avg. Moon phase : 14.64%


After over a year of experimenting with three CDK telescopes (12.5”, 20”, & 14”), this is the first light image with a successfully altered CDK14 which incorporates the extreme 0.66x Planewave focal reducer and an off-axis guider in conjunction with a mono camera and a filter wheel.

Having tried the 2.75”, 3.5”, IRF90, I settled for the Optec Gemini for the rotating focuser.

This is a first light image with the “modified” CDK setup. At f.4.7, it offers some 300% more imaging area than the native f/7.2. The signal is also boosted 220% allowing for shorter subs and less overall integration time. 3nm H-alpha subs were still long at 600s.

This data was binned 2x to achieve 0.92”/pixel which is a good match for the current (awful) seeing conditions at around 3.0”. But much higher resolution is possible when needed, Bin 1x image scale is at 0.46”/pixel that should support up to 1.4” seeing (3x).

The overall integration time relatively short as that was all that was possible over several weeks from cloudy Vancouver, the target was low at 50 – 30 degree above the horizon. Location was a Borlte 6 backyard. Some of the data was reluctantly collected through light clouds.

Interestingly, some IFN is visible even with the local light pollution and short integration time.

The large FOV and boosted signal came in very handy and allowed an acceptable SNR as well as two targets to be captured at once, especially since we only have 2hr 15mins of dark sky here now and its getting sorter by the day to a point where there are no astronomically dark nights for a several weeks!

Overall, I’m happy with the performance and have a few more tweaks and upgrades pending but I believe this setup should work well given the lack of clear sky here.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *