This camera is the smaller brother of the popular ASI290MM. It comes in a smaller, lighter body 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 that comes with SUB3.0 cameras and want to save a little bit of cash for some other astronomy gadget. But that's not the only reason why you would want to go for this product as you will see from further description of the product...
Due to its high sensitivity sensor, when combined with a wide field guide scope this camera will offer a good guiding solution.
It's a small sensor, so it will make a very good planetary imager, plus it can be used for high magnification solar and lunar imaging when not used for guiding. It might even be successfully used for taking images or really small deep sky objects, just don't forget that this is a monochrome camera...
We'd also recommend to read the product description of the high end (USB3.0) version of this camera for further details and comparison of features to get an idea which one would suit you better.
ZWO's first mini camera, the ZWO ASI290MM Mini camera integrates a Sony IMX290 1/3″ sensor (5.6 mm x 3.2 mm). This camera offers 1936 x 1096 pixels resolution with 2.9 μm x 2.9 μm pixel size. It provides 12bit ADC and its QE peak is over 80%.
Sensor: 1/2.8″ CMOS IMX290/IMX291
Resolution: 2.1Mega Pixels 1936×1096
Pixel Size: 2.9µm
Exposure Range: 32µs-2000s
ST4 Guider Port: Yes
Focus Distance to Sensor: 8.5mm
Shutter Type: Rolling Shutter
Protect window: AR coated window
Operating System Compatibility: Mac, Windows, Linux
Bit rate: 12bit output(12bit ADC)
Adaptor:1.25″ / M28.5X0.6
Dimension: φ36mm X 61mm
Weight: 60g or 3.1 ounces (without lens)
Working Temperature: -5°C—45°C
Storage Temperature: -20°C—60°C
Working Relative Humidity: 20%—80%
Storage Relative Humidity: 20%—95%
USB2.0 MAX FPS
2X2Bin :968×548: 20.4
More resolutions can be user defined
The ASI290 Mini camera offers you very good performance for planetary imaging and guiding, plus it could be also use for some specific deep sky targets and high magnification lunar and solar work.
Low read noise, high dynamic range, QE peak above 80%, 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.