Can a Planetary Astro Camera image DSOs?

After several years of using my ZWO ASI120MC for planetary imaging, I recently upgraded to another model, the ASI224MC. The newer camera is not in fact new, having been available for a few years, but it offered higher frame rates, lower read noise and higher sensitivity than the 120MC. The forums were full of positive feedback on this camera, so for £200 I thought, why not?

I had in mind a few initial targets for the 224MC which weren’t ones I’d imaged with the 120MC. They lay beyond the solar system in the deep sky, and the promise of exposures beyond the 7s I’d stretched to in a couple of 120MC experiments suggested bright, small DSOs were in range.

Naturally I made a video of the experiment for my YouTube channel. It’s here.

My favoured video capture tool is now Firecapture, but reading around I soon found that DSO imaging with a planetary camera more closely resembled “normal” DSO imaging in that Firecapture was configured to output a series of single frames, in a FITS format, rather than it’s usual .AVI videos of planets. Here are a few shots of the work in progress and some of my initial results.


Messier 13 using Firecapture and an ASI224MC

The process then used Deep Sky Stacker as per my normal DSLR approach, and then Paintshop Pro.

Messier 13 using Firecapture and an ASI224MC
Stack of 69 10 second frames of M13


Messier 81 using Firecapture and an ASI224MC – 10s subs, quite noisy

I used Firecapture’s Dark Frame setting for M81. You are prompted to add the lens cap and the software grabs 5 frames which are then subtracted from each FITS frame output.

Messier 82 using Firecapture and an ASI224MC – 20s subs

One great thing about not using video files  Рdownload size! Your laptop with be happier this way.

The Owl Nebula
Messier 97 using Firecapture and an ASI224MC – amp glow in lower right?

So after a few nights of trial and error I concluded that better results came from 20s+ exposures than 10s, and that a gain of 250 (unity) probably hit the spot rather than pushing up towards 400. As with all astro, more time on target in the form of more frames than the typical 30 minutes I used will help.

But the claim is proven – the ASI224MC is a ZWO camera that do both planetary and deep sky imaging. If yours hasn’t looked beyond the planets then give it a try.


Astro rig. Waiting for the night.
WO GT81, ASI120 guidecam and ASI224 Deep Sky camera wait for the night.


Jenham's Astro - deep sky with a planetary camera
ZWO ASI224MC and its DSO captures