REVIEW:
ZWO ASI 220MM Mini
First published February 2026
Intro
I’ve recently upgraded my guiding set-up, going from a William Optics 50mm guidescope and ASI 120MM guidecam, to an Askar M54 Off-Axis Guider and ASI 220MM guidecam. This review shares my impressions of the ASI 220MM Mini in real-world use, and looks at whether it’s a worthwhile upgrade for astrophotography guiding, particularly when imaging from an urban environment.
Modern guidecam
Guidecams are essential components of a complete astro-imaging rig. Couple one with a guidescope or Off-Axis Guider, and your mount should be able to track with a high level of precision.
The ZWO ASI 220 MM is a neat little device, with a diameter of 36mm and a length of just 61mm. It’s also almost light as a feather, weighing in at a mere 60g. Its nose fits 1.25″ adapters, which is industry standard in the world of astrophotography.
You get a good range of accessories in the box, including a USB C cable. I use this to connect my 220MM to an ASIAIR Plus.
I’ll flag one thing that almost tripped me up: the gain may need to be increased in the ASIAIR’s guiding menu. I had to do this so that multiple stars were detected, and so multi-star guiding was unlocked.
120MM vs 220MM
Until this upgrade I’d been using an earlier version of this guidecamera, the 120MM. There’s about £100 difference between the two, so what bang does that extra buck buy you?
Well, a better sensor, basically. The 120MM’s sensor is 4.8mm x 3.6mm, while the 220MM’s is 7.68mm x 4.32mm. This gives you a wider field of view with which to find guide stars. The 220MM also has a higher resolution (1920×1080, compared to the 120MM’s 1280×960). And it has a higher quantum efficiency to boot, which makes it easier to find fainter stars.
Whether or not these extras are needed for you rather depends on your set-up. If you’re using a guidescope on a wide-field refractor (like my former ‘scope the Askar FRA400) then the cheaper 120MM will do for you. If you’re using a longer focal-length telescope (like my Askar 130PHQ) with an Off-Axis Guider, then the 220MM is definitely a useful upgrade. The benefits of the improved sensor — wider field of view, higher resolution, more sensitive — will result in a tangible improvement.
In conclusion…
The ZWO ASI 220MM Mini is great. If you’re after a guidecamera then it’s a solid choice, and there’s not really anything to dislike. It’s perhaps overkill if you’re using a wide-field rig, but the cost difference over a 120MM may be small enough that you can justify going with the 220MM and having a more future-proof set-up. For longer focal lengths, and OAG users in particular, I give it a strong recommendation.
Where to buy
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ZWO ASI 220MM Mini
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