On the night of September 24, 2018, I set out with a clear goal in mind: to capture M101 — the beautiful, face-on spiral galaxy that had fascinated me ever since I first saw it in Stellarium. This night marked a turning point for me, as it was one of the first times I approached deep sky imaging with real planning. I had begun learning how to find and frame DSOs using Stellarium, and with that came a whole new set of questions I hadn’t considered before.
Where should I set up my scope so the object wouldn’t vanish behind a neighbor’s garage halfway through the session? When would the object rise high enough to be worth imaging? Would it cross the meridian and force a meridian flip — something I still found intimidating? And which alignment stars should I use to improve my chances of actually finding it, given the notorious slewing errors of my modest EQ3 Pro mount?
Despite these unknowns, I chose M101 — not because it was easy, but because I loved the idea of capturing a distant galaxy with graceful spiral arms. In hindsight, maybe not the best target for that night… and here’s why:
It was the first full moon with my telescope. Naturally, I wanted to try some lunar imaging too — and yes, you’re probably already connecting the dots. Trying to image a faint galaxy like M101 under a full moon was, in retrospect, ambitious at best.
I began the night capturing a few quick sequences of the Moon using my Canon compact camera held up to the eyepiece — the classic ocular projection method. My plan was to stack the video frames later in Autostakkert!2. I also took a few shots at prime focus using the old Olympus E-5II, just to compare results.
Next up was Mars. Still using the compact Canon and the eyepiece projection setup, I recorded some short .mov files. Mars was sitting low on the horizon, and the atmospheric seeing was pretty rough. Visually, it was little more than a red blur bouncing across the field of view.
Finally, I returned to M101 with the Olympus camera and took 51 light frames at 60 seconds each, along with 20 darks and 20 bias frames at ISO 800. The setup and capture had gone well — but the full moon washed out nearly all of the signal. The histogram showed a sharp spike buried in noise. My early attempts at stretching the data were hopeless; the galaxy nearly vanished in the background. Eventually, my brother stepped in and managed to find a balance that preserved the faint inner structure of M101’s spiral arms. The colors were gone, the outer arms were invisible — but still, it was my first real deep sky target. A milestone. Thanks, bro.
As for Mars, processing followed the same routine as before — stacking thousands of frames from the .mov file and sharpening the best 50%. Oddly enough, this time the results were better. Either the focus was sharper, or I’d just gotten lucky with conditions. The camera’s low frame rate definitely didn’t help, though — with better gear and higher FPS, I might have gotten closer to that lucky moment of perfect seeing.
The Moon was a mixed bag. I tried stacking frames like with Mars, but the results were soft and lacked detail. Eventually, I selected a single DSLR image and sharpened it in Registax6. I probably overdid it a bit, but hey — it was my first sharpened Moon. And honestly? I still like it.
Specs:
Mars using occular projection with Canon PowerShot SX240 HS
M101 – 60sec sub @ ISO800 using Olympus E-5II
Moon single shot
Moon single shot sharpened
Vega single shot
Tech Specs of M101:
51 x 60′ lights
20 darks
20 bias
ISO 800📝 Conclusion
If you’re planning a deep sky session, plan everything. Know your object, your sky, your location, your timing — and do not forget the Moon. It can ruin your data before you’ve even taken the first frame. And make sure your target is bright enough for your aperture and your skies. M101 is a stunning galaxy, but it’s faint — even under ideal conditions, it’s a challenge for a 150mm scope. You’ll need darker skies, longer exposures, and maybe some filters to really bring it to life.
I still want to return to it someday. M101 is just too beautiful not to try again.
Clear skies,
Chris