This camera is the smaller brother of the popular ASI174MM, but comes in a smaller, lighter format with a 1.25" form factor, with USB2.0 connection instead of USB3.0, but other than that it would be a very good alternative for those who don't necessarily need the highest framerate and want to save a little bit of cash for some other astronomy gadget...
When used with smaller guide telescopes this camera will offer an enormous field of view; that combined with it very high sensitivity it's a no brainer that you will never soffer from not being able to find a suitable guide star in the field...
It would also make a good guide camera for a very large telescope (with long focal length) with a comparatively large guidescope... alternatively, due to it's comparatively large sensor it could also serve as a good solar, lunar or planetary imager camera when not used for guiding, and might even bring you some nice deep sky images, just don't forget that this is a monochrome camera...
We'd also recommend to read the product description of the high end version of this camera for further details and comparison of features to get an idea which one would suit you better.
The ZWO ASI174MM MINI camera integrates Sony IMX174LLJ / IMX174LQJ 1/1.2″ sensor (11.3 mm x 7.1 mm). It is ZWO's first mini camera with a small format, 1.25" nosepiece-style front construction. This camera features 1936 x 1216 pixels. The pixel size large at 5.86 μm x 5.86 μm. This camera provides 12bit ADC and its peak QE is 77%.
Sensor: 1/1.2″ CMOS IMX174LLJ / IMX174LQJ
Resolution: 2.3Mega Pixels 1936×1216
Pixel Size: 5.86µm
Exposure Range: 32µs-300s
Bit rate: 12bit output(12bit ADC)
Adaptor: 1.25″ / M28.5X0.6
Dimension: φ36mm X 61mm
Working Temperature: -5°C—45°C
Storage Temperature: -20°C—60°C
Working Relative Humidity: 20%—80%
Storage Relative Humidity: 20%—95%
The ZWO ASI174 ini camera offers you very good performance for planetary, solar, lunar imaging and guiding. Low read noise, high dynamic range, QE peak 77%, AR protective window and much more.
Sensitivity is the first thing we considered. It is very important to find a guide star. So for start, we were considering to use only a mono sensor to design our guide camera, because a mono sensor has much higher sensitivity than color ones. After that, we carefully compared the sensitivity of our sensors. At last, we decide to use 290 and 174 mono sensor. As we know, 290 and 174 mono sensors have about 80% peak QE, so these can detect more stars in the field of view. Also, we can shorten the exposure time in guiding that might make guiding more precise.