Except for the galaxy M74 these are all clusters. Except for M56 they are all a dozen or so 80 second ISO 800 shots with the canon t3i through the william optics z61(360mm, f/5). M56 was accidentally done at 10 sec ISO 6400. I’m not sure it suffered all that much for the skimping.




These are crappy, pro-forma, messier sweep images but I like them. I was shooting for M73 which was too close to my roof and getting closer so i grabbed a dozen shots 10 seconds at iso 6400. The one above with the roofile out of focus at the bottom has a nice sky colour. It’s cropped below to show M73 – an asterism of four stars near the left – and M72, a larger globular cluster on the right.

SO. Much. Messier!

In one evening I targeted 8 Messier objects from my back yard. The evening before i had done several others. These are all quick and dirty captures – mostly 12X80 seconds at ISO 800 through the William Optics Z61 – 360mm f/5. Most of the targets are either global or open clusters which i don’t find that interesting. The exceptions are the galaxy m74 and the “little dumbbell” nebula m76 both of which could have stood more time. There’s a more cropped version of m76 along with it.


M40 – Messier’s Mistake

M40 is a double star in Ursa Major – easy to find but not that interesting. Not clear why it got included in Messier’s catalog. The green circle outlines HD238107 and Hd238108 both around magnitude 10. Toward the bottom left is Megrez(mag 3) in Ursa Major where the handle of the big dipper meets the bowl. Between there and M40 is UMa 70(mag 6). Off to the top left is the track of starlink-2657.

This is a quick and dirty capture – 8 images at 90 seconds 800 ISO through the william optics z61(360mm f/6). Processed in Siril with colour calibration, auto histogram, and asinh.

And How About That Takumar!

One of he objects I was excited to shoot with the Z61 was M57 the Ring Nebula. I had captured it with the Takumar 200mm f/4 lens and I thought the larger scope and longer focal length would improve it. It did, sort of, but the Takumar image is still prettier.

On the left above is the Takumar 200mm f/4 11 shots, iso 800, 25 seconds. On the right is the Z61 360mm f/6, 12 shots at iso 800 60 seconds. Both processed about the same way in siril and cropped to the same area then the Z61 image was resized 66% to compensate for the focal length. The Z61 shot clearly show more stars but the image has lots its charm. Maybe I just blew out the ring with too much exposure.

The two exposures are not that different though. The formula is something like L=f^/(iso*time) and 4^2/(25*800) is not very different from 6^2/60*800. So maybe processing.

The Late M42

I’m not entranced with M42, it’s just kind of big and blah. I came across though a sequence I had taken and processed in January and decided to re-do it to see if my siril processing skills were any better. I would say not. Both images below are based on 60(!) 15 second shots at ISO 800. The second is the reprocessed one which theoretically would have better background removal and color calibration. The only thing I’d say is that i probably raised the black point more on the second one. I’m not sure why i did so many short exposures – maybe full moon or snow cover. it would have been better to lower the ISO and do fewer longer shots just to shorten processing. And I still don’t care about M42.

M14 and M92


These don’t amuse me nearly as much as nebulae and galaxies but i guess i’m going to work through the messier catalog as they wheel past me. M14 and M92 are both about 30,000 light years away so part of our galaxy.

These are both low effort images – 9 or 10 exposures at 60 seconds for M92 and 90 seconds for M14 all at ISO 800 with the canon t3i on the William Optics Z61(360mm f/6).

M102 is Shy But Has Distant Companions.

M102 is a small galaxy considered to be the same as NGC5866. It’s visually small even as galaxies go but it was in an easy part of the sky last night so i captured 30 subs of 60 seconds ISO 800 with the canon t3i and the william optics z61(360 f/6). The usual processing in Siril. The second picture below shows a broader crop where two other galaxies are obvious – NGC5879 on the lower left and NGC5905 on the right. M102 is about 50 million light years away. The third picture is a screencap of wikipedia’s image of M102 and the final one is wikipedia’s NGC5907 both of which blew me away.

M104 – Sombrero Galaxy

Thirty lights 60 seconds each at ISO 800 with the canon t3i through the William Optics Z61(360mm f/6). Processed in Siril with photometric colour calibration and asinh.

I took it for the Sombrero Galaxy but my eye is always caught by the patterns formed by stars in these images. Toward the top right is what feels like a cartoon of a rocketship fleeing the frame and near the middle left there’s kind of an arrow pointing to it. It’s all just perspective though – the sombrero galaxy is 30 million lightyears away and the individual stars are all in our own galaxy but nowhere near each other some are as “close” to us as a few hundred light years and some over 1,000.

My rocketship though is apparently well known as the “Stargate” asterism STF 1659.

M3 – I’m Dithering!

Over-processed as always, this is 40 25 second shots at ISO 800 through the Z61(360mm f/6). Processed with siril’s photometric colour calibration then the black point raised .2. Of the 40 shots, 30 had dithering applied. That’s easy to do, just a button in Backyard EOS, but i can’t see that it made a difference.

Below is a comparo where i processed 10 images with no dither(ND), 10 with dither(D10), 30 with dither(D30) and the whole lot(ALL40).