With the advantage of low readout noise and high-speed readout, CMOS technology has revolutionized astronomical imaging. A monochrome, back-illuminated, high-sensitivity, astronomical imaging camera is the ideal choice for astro-imagers.
The QHY268M/C is a new generation of back-illuminated CMOS cameras with true 16-bit A/D and 3.76um pixels. This new Sony sensor is an ideal CMOS sensor exhibiting no amplifer glow. 16-bit A/D gives high resolution sampling of the whole full well range. Digitizing 0-65535 levels yields a smooth image with continuous gradation of greyscale levels. The QHY268M/C is a cooled, back-illuminated, CMOS camera based on the Sony IMX571 sensor with native 16-bit A/D and 3.76um pixels.
1GB 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 QHY268 has adopted a large-capacity memory of up to 1GB. 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.
Extended Full Well Capacity and Multiple Read Modes
With a pixel size of 3.76um, 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 full well readout mode, the QHY268 can achieve nearly 75ke-. Greater full-well capacity provides greater dynamic range and large variations in magnitude of brightness are less likely to saturate.
Other Notable Features
- Native 16 bit A/D: 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 1e-/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 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.
- Zero Amplify Glow: This is also a zero amplifer glow camera.
- 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.
What's In the Box
- 12V AC power adapter and cable
- USB 3.0 cable (1.8m)
- Self-locking power cable
- M54 turning 2-inch adapter ring
- Driver download instruction
- Center/tilt adjustment ring
- Adapter kit D1 (to connect QHY268C+(QHYOAGM) w/ MPCC with 55mm BFL & M48 adapter)
||SONY IMX571 C
||3.76um x 3.76um
|Effective Pixel Area
||6280*4210 (includes the optically black area and overscan area)
|A/D Sample Depth
||Native 16-bit (0-65535 greyscale) A/D
|Full Well Capacity (1×1, 2×2, 3×3)
||51ke-75ke- or above in extended full well mode
|Full Frame Rate
- Full Resolution: 6.8FPS @8BIT - 6FPS @16BIT
- 2048 lines: 13.6FPS @8BIT - 11.5FPS@16BIT
- 1080 lines: 25.4FPS @8BIT - 19.5FPS@16BIT
- 768 lines: 35FPS @8BIT - 25FPS@16BIT
- 480 lines: 50FPS @8BIT - 34FPS@16BIT
- 1.1e- High Gain
- 3.5e- Low Gain
- (5.3e- to 7.4e- in extended full well mode)
- -20C, 0.0005e /pixel/sec
- -10C, 0.001e /pixel/sec
|Exposure Time Range
*With the improvement of the CMOS technology, the 16bit CMOS camera has been released, like QHY600/268/411/461. For these cameras, even in lowest gain it has beyond the requirement of unit gain (less than 1e/ADU due to sufficient samples) So you can directly set gain0 as start. Please note QHY600/268C/411/461 has extend full well mode. In this mode you still need to find out the unit gain position.
- 0 (PH Mode)
- 30 (Extended Full Well Mode)
||Zero Amplifer Glow
|Firmware/FPGA remote Upgrade
||Fully support via Camera USB port
|Built-in Image Buffer
||1GByte DDR3 Memory
- Two-stage TEC cooler
- Less than 1S lower than ambient temperature -30C in continuous mode
- More than 1S continuous mode or lower than ambient temperature -35C in single frame mode
- Note: Test temperature +20°
|Optic Window Type
||AR+AR High Quality Multi-Layer Anti-Reflection Coating
||M54/0.75 (with CAA) and M48 (with standard adapter)
|Back Focal Length
||QHY268C: 17.5mm (without CAA)
This intercept does not include CAA. If CAA is used, it increases by 6mm (23.5mm total). Please check the mechanical drawing below for details.