QHY268M cooled monochrome CMOS Camera with SONY IMX571 Sensor, D= 28 mm

QHY268M cooled monochrome CMOS Camera with SONY IMX571 Sensor

The QHY268M/C is a new generation of back-illuminated CMOS cameras with true 16-bit A/D and 3.76 µm pixels. This new Sony sensor is an ideal CMOS sensor exhibiting no amplifier glow. 16-bit A/D gives high-resolution sampling of the whole full well range. Digitizing 0-65535 levels yields a smooth image with a continuous gradation of greyscale levels.

1 GB DDR3 image buffer
In order to provide smooth uninterrupted data transfer of the entire 26MP sensor at high speed, the QHY268 has 1GB DDR3 image buffer. The pixel count of the latest generation of CMOS sensors is very high resulting in greater memory requirements for temporary (and permanent) storage. The ALccd-QHY268 has adopted a large-capacity memory of up to 1 GB. Data throughput is doubled. This large image buffer meets the needs of high-speed image acquisition and transmission of the new generation of CMOS, making shooting of multiple frames smoother and less stuttered, further reducing the pressure on the computer CPU.

Reboot the camera by power off and on
The camera is designed to use the +12V to reboot the camera without disconnecting and reconnecting the USB interface. This means that you can reboot the camera simply by shutting down the +12V and then powering it back on. This feature is very handy for remote controlling the camera in an observatory. You can use a remotely controlled power supply to reboot the camera. There is no need to consider how to reconnect the USB in the case of remote control.

Random change thermal noise suppression function
You may find some types of thermal noise can change with time in some back-illuminated CMOS cameras. This thermal noises has the characteristic of the fixed position of typical thermal noise, but the value is not related to the exposure time. Instead, each frame appears to have its own characteristics. The ALccd-QHY268 uses an innovative suppression technology that can significantly reduce the apparent level of such noise.

Extended Fullwell Mode and several readout modes
With a pixel size of 3.76 µm, these sensors already have an impressive full well capacity of 51ke. Nevertheless, QHYCCD has implemented a unique approach to achieve a full well capacity higher than 51ke- through innovative user controllable read mode settings. In Extended Fullwell Mode, the ALccd-QHY268 can achieve an extremely large full-well charge value of nearly 75 ke-. Greater full-well capacity provides greater dynamic range and large variations in magnitude of brightness are less likely to saturate. The QHY268 has three readout modes with different properties.

Native 16 bit A/D conversion
The new Sony sensor has native 16-bit A/D on-chip. The output is real 16-bits with 65536 levels. Compared to 12-bit and 14-bit A/D, a 16-bit A/D yields higher sample resolution and the system gain will be less than 1 e-/ADU with no sample error noise and very low read noise.

BSI
One benefit of the back-illuminated CMOS structure is improved full well capacity. This is particularly useful for sensors with small pixels. In a typical front-illuminated sensor, photons entering the light-sensitive layer of the sensor must first pass through the metal wiring embedded directly above the light-sensitive layer. The wiring 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.

Zero Amplifier Glow!
This camera shows no relevant amplifier glow.

Optimizing USB Traffic to Minimize Horizontal Banding
It is common behavior for a CMOS sensor to contain some horizontal banding. Normally, random horizontal banding can be removed with multiple frame stacking so it does not affect the final image. However, periodic horizontal banding is not removed with stacking so it may appear in the final image. By adjust the USB traffic in Single Frame mode or Live Frame mode, you can adjust the frequency of the CMOS sensor driver and it can optimize the horizontal banding appeared on the image. This optimizing is very effective to remove the periodic banding in some conditions.

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 Control
Based on almost 20-year cooled camera design experience, The QHY cooled camera has implemented the sealing 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. The sensor itself is kept dry with QHY´s 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.

- Camera head
- Adapter dovetail ring to M54
- Adapter 2" barrel to M54
- USB3.0 cable (1.5 m)
- Storage box
- Software (EZCap) and drivers (Windows system drivers and ASCOM) on CD

Safety informations: PDF Download