With the advantage of low readout noise and high-speed readout, CMOS technology has revolutionized astronomical imaging.  The QHY533M/C is a new generation of back-illuminated CMOS cameras with 3.76um pixels.  The QHY533M/C uses the similar series of sensors as the flagship models QHY600 and QHY268, featuring low noise.

BSI

One benefit of the back-illuminated CMOS structure is improved full well capacity. This is particularly helpful for sensors with small pixels.In a typical front-illuminated sensor, photons from the target entering the photosensitive layer of the sensor must first pass through the metal wiring that is embedded just above the photosensitive layer. The wiring structure reflects some of the photons and reduces the efficiency of the sensor.

In the back- illuminated sensor the light is allowed to enter the photosensitive surface from the reverse side. In this case the sensor’s embedded wiring structure is below the photosensitive layer. As a result, more incoming photons strike the photosensitive layer and more electrons are generated and captured in the pixel well. This ratio of photon to electron production is called quantum efficiency. The higher the quantum efficiency the more efficient the sensor is at converting photons to electrons and hence the more sensitive the sensor is to capturing an image of something dim.

TRUE RAW Data

In the DSLR implementation there is a RAW image output, but typically it is not completely RAW.  Some evidence of noise reduction and hot pixel removal is still visible on close inspection.  This can have a negative effect on the image for astronomy such as the “star eater” effect.  However,  QHY Cameras offer TRUE RAW IMAGE OUTPUT and produces an image comprised of the original signal only, thereby maintaining the maximum flexibility for post-acquisition astronomical image processing programs and other scientific imaging applications.

Anti-Dew Technology

Based on almost 20-year cooled camera design experience, The QHY cooled camera has implemented the fully dew control solutions. The optic window has built-in dew heater and the chamber is protected from internal humidity condensation. An electric heating board for the chamber window can prevent the formation of dew and the sensor itself is kept dry with our silicon gel tube socket design for control of humidity within the sensor chamber.

Cooling

In addition to dual stage TE cooling, QHYCCD implements proprietary technology in hardware to control the dark current noise.

Amplify Control

Compare to the last generation’s astrocam for beginners, like QHY183 or QHY 163, QHY533M has much better amplify control.

QHY533M Dark Frame, 300s

QHY183M Drak Frame, 300s

QHY533M Drak frame, 600s, with highest gain (170) and strech–only very slight amplify can be detected at the corner.

Design

QHY533M (mono) and 533C (color) have different interface designs to be more flexible to deal with different applications.

QHY533M can be directly connected to the QHYCFW3S-SR without removing any part of the filter wheel (like the filter container). This provides a very short back focal length and that’s easy to fix! Besides, QHY533M + QHYCFW3S-SR combination can be easily connected to a DSLR lens, with only one additional adapter (sold separately).  

Both QHY533M/C comes with an additional adapter for tripod interface. This makes it easier to shoot with DSLR lens.

QHYCFW3S Adjustment for QHY533M

In order to let all astrophotographers easily use 533M’s threaded interface to connect filter wheel without removing any part of the filter wheel (like the filter container), since 2022, QHYCFW3-SR won’t be loaded with this adapter (below).  This adapter is used to connect QHY163 or QHY183 while QHY533M doesn’t need it. Therefore, if you want to get a QHY533M, we recommend you choose QHYCFW3S-SR for the best experience.

By the way, this adapter is still contained in CFW3S-SR’s package. You can still use CFW3S-SR with QHY183 or QHY163.

QHY533M Parallel Position Adjustment

The QHY533M is connected to the QHYCFW3S by using threads， so the sensor may not parallel to the filter wheel when the threads are fully rotated. In this case you can adjust the front part of the 533M to the right angle of the sensor.

QHY533C Design

A free Adapter Kit E will be provided with QHY533C. The adapters can be directly connected to the 55mm BFL M48 interface MPCC, or Nikon / Canon DSLR lens (need to purchase another DSLR lens adapter). At the same time, the C-port thread can be provided with the QHY533C and you can directly mount the C-port lens.

Specifications

Curves

Mechanical Dimensions

QHY533M

QHY533C