📾 First Light for the DSLR – First Deep Sky Object – and Saturn, Again

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A few days before this session, I got my hands on a T2-to-4/3 Olympus adapter ring — a small piece of metal that opened up a whole new world. With it, I could remove the lens from my brother’s old Olympus E-510 DSLR and attach the telescope directly, turning my SkyWatcher 150/750 PDS into a giant prime lens.

Naturally, I aimed high: M31 — the Andromeda Galaxy, my first deep sky target.

At this point, polar alignment was still a major challenge. But after some digging, I came across a clever SkyWatcher method: a rough alignment followed by a three-star alignment, and then refinement using a guide star. The mount slews to the guide star, I correct for the error, and it slews again. I then use the ALT and AZ bolts to recenter the star — and voilà, a decently aligned mount without Polaris in sight and no laptop required.

Thanks to this method, I was able to take 60-second exposures without noticeable trailing — a huge milestone.

🔧 Technical Details

  • 12 x 60s light frames
  • 5 x 60s dark frames
  • No calibration frames
  • ISO 400

đŸ–„ïž First Steps in Processing

This was our very first deep space image, and everything was new territory. We stacked the data using DeepSkyStacker, which instantly became one of my favorite tools. It’s clean, intuitive, and offers just enough control without overwhelming the beginner. Even now, I still use DSS after every session.

Image processing in Photoshop and GIMP2, however, was a different beast. Learning how to stretch the histogram, mask regions, adjust contrast, and enhance faint structures was both exciting and frustrating. But slowly, something resembling Andromeda began to emerge.

🎯 Reflections and Lessons Learned

Looking back, I only wish we had taken more light frames. The setup was working beautifully — but we simply didn’t realize how long it takes to collect enough photons. The signal-to-noise ratio was far too low with only 12 subs, but at the time we had so little guidance. Still, my brother did an excellent job cleaning up the image in post, smoothing noise while preserving detail.

Yes, the color balance is off, the stars are bloated, and the contrast might be a bit much — but this is our first deep sky image. And I still love it.

🌌 The Wonder of Stacking

That night was also the first time I witnessed the magic of stacking. Comparing an unstacked sub to the final output from DSS was like night and day. The moment Autosave.tif pops up, revealing the cumulative power of all those faint photons, still fills me with excitement. It really does feel like science and art coming together.

đŸȘ Second Target: Saturn (Yes, Again)

I couldn’t resist turning back to Saturn. I mounted the Canon PowerShot SX240 HS in front of the eyepiece and recorded a short .mov video. This time, the raw video was much brighter and clearer than our first attempt. The final processed frame showed Saturn’s distinct shape and iconic rings. No Cassini Division yet — but still, real structure. Progress!

🌙 Third Target: The Moon

To round out the night, we captured a single frame of the Moon using the Olympus DSLR on the telescope. At 750mm focal length and with a cropped 4/3 sensor, the Moon fit perfectly into one frame — which was great, as I didn’t need to stitch a mosaic. It was just a quarter moon, not full, but the detail was beautiful. We sharpened the image a little in GIMP2, and the result was crisp and clean.

A big night. A big step. And the beginning of a deeper dive into the cosmos.

Clear skies,
Chris