Category Archives: Star Clusters

Test of Canon 200mm F/2.8 Telephoto with QHY183c Camera

M45, The Pleiades. 56×30 sec, QHY183c, Gain 20, Offset 31, -15C, Canon 200mm F/2.8.
The North American Nebula. 167×30 sec, QHY183c, Gain 2, Offset 31, -15C, Canon 200mm F/2.8.
The Horse Head Nebula Region. 8×120 sec, QHY183c, UHC Filter, Gain 20, Offset 31, -23C, Canon 200mm F/2.8.

I bought the adapters needed to mate my new QHY183c camera to my Canon lenses.   I tried it out with the 200mm F/2.8 telephoto.   No way to control the F-stop diaphragm, since it needs a Canon camera to do that, so I had to shoot with it wide open.  BTW, this was from the light polluted metro area I’ve been shooting from lately.

Since this is one of the cheaper lines of Canon lenses, it suffers from optical imperfections like astigmatism.   That makes the red focus to a line up and down and blue and green focus to a line left to right.   It really messes up the star shapes and there is no way to fix it except to stop the lens down to F/3.5 or higher.   Oh, well…

Great Night for EAA and Imaging with New QHY183c Camera

M27 – 90×30 sec, QHY183c at -25C, Gain 30, UHC filter, TV-85 at F/5.6.
M27 – Close Crop Detail. 90×30 sec, QHY183c at -25C, Gain 30, UHC, TV-85 @ F/5.6.
Eastern Veil Nebula – 103×30 sec, QHY183c at -25C, Gain 30, Offset 25, UHC filter, TV-85 at F/5.6.
M31 – 90×30 sec, QHY183c at -25C, Gain 30, UHC filter, TV-85 at F/5.6.
M33 – 30×30 sec, QHY183c at -25C, Gain 30, UHC filter, TV-85 at F/5.6.
M45 – 100×30 sec, QHY183c at -25C, Gain 30, UHC filter, TV-85 at F/5.6.
M42 – 40×30 sec, QHY183c at -25C, Gain 30, UHC filter, TV-85 at F/5.6.

What a night!  My new QHY183c astro camera worked really well once I had it hooked to a computer that could handle the 20MP downloads and live stacking requirements of SharpCap 3.2.  I used my older  Panasonic ToughBook for controlling the scope and the guiding while another laptop, a Toshiba i7-based unit, was used for image acquisition and live-stacking.  I was able to bag six objects with this setup before I had to turn in and get some sleep.

(BTW, EAA is Electronically Assisted Astronomy.  It is a way to “observe” from a light-polluted metro area with real-time captures and strong LP filters on a computer using highly sensitive astro cameras.)

SharpCap 3.2 works really well on the faster machine but not on the ToughBook.  The USB 3 port and it’s 2.5Ghz processor are just not powerful enough, I guess.  I will have to tuneup the Toshiba to do all the stuff the ToughBook was doing and live-stack with SharpCap, all at the same time.  Hopefully, I’ll take care of that soon.

M71 Open Cluster – Sony IMX224

M71 Open Cluster. 75×8 sec Gain 1642, Sony IMX224, TV-85 at F/5.6, Sharpcap 2.9.

Right under the Dumbbell Nebula is is M71, a tight open cluster that looks like an arrowhead.   It has the tightly packed appearance of a globular, but it is not.  This is 10 minutes worth of exposure in 8 sec sub-images.

The image below is a shot with about 16 minutes of exposure (119 x 8 sec.)  I caught a few more background stars, I think.

M71 Open Cluster. 119×8 sec. Gain 1642, Sony IMX224, TV-85 at F/5.6, Sharpcap 2.9.

M15 & M2 Globular Clusters & NGC 7789 Open Cluster – Sony IMX224

M15 Globular – 181×1 sec, Sony IMX224, TV-85 at F/5.6.
M2 Globular Cluster. 75×4 sec, Sony IMX224, TV-85 at F/5.6.
NGC 7789 Open Cluster. 157×4 sec, Sony IMX224, TV-85 at F/5.6.

First appreciable cold front with clear skies came through, finally.  I managed to get some scope time to do a shake-down imaging session to test equipment.   This was on the night of Oct 11, 2018 and I was shooting from a Bortle Red zone in the city.    I shot a few things playing around and these were the best three pictures of the bunch.   Not the prettiest astro images , but at least I got to see what stuff still works and what did not after not imaging since March 2018.

My USB hub and some cables probably need replacing.  The hub has seen better days.  There is lots of corrosion inside the connectors.  These connection problems precipitated other problems with the laptop and my EQMOD settings got trashed.   I had to delete the AppData/Roaming/EQMOD  folder to fix it.  That required me to redo all the location settings, guide speeds, etc.   Could have been worse, I guess.

I managed to update drivers and the astro-related software on the laptop, which was a good thing.   My Toupcam IM224 had a batch of new drivers released the very same day as the imaging session.   I could not have timed it better.  lol

Oh, and my dew strap for the TV-85 was not working, either.   The wire broke inside the strip, so I just tossed it.   Oh, well.    Luckily, it was so dry this night I did not have to worry about any dew.