The QHY21/22/23 camera uses SONY's high-sensitivity EXview II CCD chips. Although not back-lluminated, the QE of these sensors is very close to the performance of back-illuminated sensors (nearly 80%) and also exhibit very low dark current noise.
2-Stage Cooling -45C Delta T
The cameras have a typical cooling capacity of -45 degrees Celsius below ambient temperature, producing exceptionally low dark current. Often, imagers do not bother to subtract dark frames with these sensors.
Low Read Noise Better Image
These cameras have typical read noise around 5 electrons. When shooting dark targets and using narrow-band filters, low readout noise means smoother images, and you can get better images after stacking.
Small Size Wide Range of Applicable Telescopes
The pixel sizes of the sensors used in the QHY21, 22, 23 cameras are relatively small. Compared with larger pixel CCDs, this allows for higher detail using smaller telescopes. You can get a stunning view with a shorter focal length optical system.
A fixed clip for the USB and power cord is included. Even if the equatorial mount is slewing at high speed, you won't lose the USB and power cord. Anti-dew measures include a sealed CCD chamber with a desiccant tube connector and CCD chamber window heater.
An electronic shutter makes fast exposures possible with accurate exposure timing.
The self-locking filter wheel cable is secure and reliable.
The camera has a deep cooling capacity typically below -45 degrees Celsius.