Category Archives: Star Clusters

Two Globular Clusters with the 6 Inch, F/8 Newt

M13. 70×4 sec, Gain 3704, RT Sony IMX224, Orion 6 inch, F/8 Newtonian.

Here are two globular clusters, M13 and M4, that I took with an Orion 6 inch F/8 newt and a Rising Tech Sony IMX224 eyepiece cam.

M4 Globular Cluster. 27×4 sec, RT Sony IMX224, Orion 6in, F/8 Newtonian.

I reworked the first M13 image and tried for better color.   Here’s what I got:

M13. 70×4 sec, Gain 3704, RT Sony IMX224, Orion 6 inch, F/8 Newtonian. Version 5.

M67 Open Cluster – 6 Inch Newt at F/8, (1200 mm Focal Length)

M67 Open Cluster. Orion 6 inch, F/8 and RT Sony IMX224 eyepiece camera. 201 x 2 sec at gain 2650.  Up-scaled 200% in processing.

I purchased some rings and an extra-long dovetail bar for my Orion 6 inch, F/8 dobsonian and mounted it on the Atlas EQ-G.   It has a really narrow view with a Sony IMX224 chip camera, but its sharp and there was not much distortion throughout the entire field.

The newt lets you shoot with no filters and you pick up everything, including IR, with the standard clear filter that Rising Tech cameras ship with.    That’s great for galaxies.    Although this first test shot was not a galaxy, I hope to try it out on some, soon.

The rig is sensitive to balance and wind being the tube is so long and is also very sensitive to vibrations.   Since I was imaging next to a busy parking lot, I noticed lots of rejected frames in the SharpCap stacking program when the activity there increased.  Even loud noises would disturb it.   LoL.

Although conditions were not the best and the red zone light pollution I imaged through kept me from getting really deep, I did manage to do a few test shots before conditions deteriorated,

The above image was actually the second shot of the night, the first one being this unknown star field below that I shot to test the tracking.  It was a little difficult to dial-in a star to get a 3-star alignment on the mount, so I just went with seeing how long I could track with PHD2 Guiding at the same old settings I used with the TV-85 on a random star field.    8 sec exposures yielded too many rejected frames, so I went with 4 sec for this one.

Unknown star field. 70×4 sec @ Gain 2067, RT Sony IMX224 cam, 6″, F/8 newt, Atlas EQ-G w/EQMOD, PHD2 guiding w/Orion Ultra-mini and StarShoot.

Before the clouds came back and ruined my session, I was able to get 60×4 sec sub-images at the relatively high gain of 3108 of this open cluster in Gemini, called IC 2157:

IC 2157. 60×4 sec @ 3108 gain, RT Sony IMX224, 6 inch, F/8 Newt, Atlas EQ-G w/EQMOD.

Anyway, if I can get the tracking to get me up to 8 seconds of exposure, I will be able to shoot some of those tiny galaxies that my Televue TV-85 just can’t do justice to.

M35 and NGC 2158 Mosaic – Sony IMX224

M35 and NGC 2158 2-panel mosaic. Right half was taken on Dec 11, 2017. 275×8 sec and the left half was taken on Dec 13, 2017, 100×20 sec at 2098 and 1832 gain, respectively. Rising Tech Sony IMX224 cam with a Televue TV-85 at F/5.6.

As promised, here is the 2-panel mosaic of the M35/NGC 2158 area.    Not too bad, but the seeing for Dec 11 was poor and I might re-shoot the NGC 2158 side to get a better rendition.

Here’s the gaudy version that I turned up the contrast on with a strong curves boost:

M35 and NGC 2158 2-panel mosaic. Curves to boost contrast.

NGC 2158 and M35 (Partial)

NGC 2158 and part of M35 taken on Dec 11, 2017. 275×8 sec @ Gain 2098, SharpCap 2.9, RT Sony IMX224, Televue TV-85 at F/5.6. Resized to 200% in post processing.

I had in mind when starting this that I could get a mosaic going for M35 and its nearby companion, NGC 2158.    So, I started on NGC 2158 first since it is the more interesting cluster.     By the time I was finished, my window to shoot was just about over, so I moved on to something else and did not finish the mosaic.

What I did get came out OK for 8 second exposures.      I will probably go back to it the next time I use the Rising Tech Sony IMX224 eyepiece cam.    It is actually enjoyable watching SharpCap do live stacking with the short exposures.    Reminds me of the old days when I was doing mostly planetary imaging.   lol    🙂