ZWO ASI461MM PRO

The ZWO ASI461MM PRO is ZWO's first medium-format CMOS camera, using the 101 megapixel back-illuminated Sony IMX461 sensor. It features a QE up to 91%, a native bit rate of 16 bits, an ultra-high 14 stops dynamic range and ultra-low 1.0e readout noise. The large sensor size of 44mm x 33mm requires very large filters (65mm square is recommended) and a capable telescope.

Sony’s back-illuminated CMOS technology improves sensitivity, minimizes noise, reduces power consumption and increases data download speed. In back-illuminated sensors, the photosensitive surface is placed on top of the wiring so the incoming light is not obstructed, resulting in a greater quantum efficiency. 

The ASI461MM Pro features a 16bit ADC that can achieve a dynamic range output of 14 stops. This improves the image sharpness and contrast significantly and the colour shades are smoother and more natural. 

When the gain value is 100, the HCG high gain mode is automatically activated and the readout noise is greatly reduced while the dynamic range basically remains unchanged.  

The ZWO PRO cameras incorporate a 256MB DDR3 memory buffer that improves data transfer reliability and it minimizes amp-glow caused by slow data transfer speeds.The USB 3.0 Port provides 5Gbps bandwidth. The USB 2.0 Hub allows to connect 2 USB controlled accessories such as a filter wheel, a guiding camera or an electronic focuser, reducing the amount of cables that run directly from your computer.
The 2 stages TEC cooling system allows a ΔT of 35°C below air temperature. 
Note: All cooled ZWO cameras require an external power supply of 12V at 3-5A with a 2.1×5.5 mm connector (positive tip).The dew heater avoids the problem of dew condensation on the optical window of the sensor. The heater can be turned off via software.

Traditional CMOS sensors produce a weak infrared light source that is often seen in the corner of uncalibrated images as bright glow. The ASI461MM Pro uses the zero amp glow circuits that avert this artefact in your images.