The QHY21, QHY22 and QHY23 cameras use Sony's high-sensitivity EXview HAD CCD II sensors, ICX674, ICX694 and ICX814, respectively. These sensors have very high QE (close to 80%) and very low thermal noise. QHYCCD's dual stage TE cooling technology reduce the sensor temperature up to -45C below ambient for exceptionally low dark current. Compared to competing models, the QHY cameras achieve -10C to -15C extra cooling, resulting in very low noise and uniform background even during the hot summer months.
The read noise of these cameras is also a highlight of their performance. Typical read noise is around 5 electrons. Low read noise is very important when you want to capture faint deep sky objects or when using narrowband filters. Less read noise also means you can get a better image when you stack multiple frames. These Sony sensors all have relatively small pixels for high resolution. Using a suitable OTA results in outstanding detail as the sample images at the bottom of this page show.
The QHY21, 22 and 23 offer full moisture control, including an air-proof CCD chamber with silicon gel tube socket and a CCD chamber optical window heater. Mechanically, the QHY21, 22 and 23 are solidly built and include a USB/Power cable support. With this support, the USB and power cable will stay solidly affixed to the camera assuring a constant electrical contact.