QHY268C - PHOTOGRAPHIC COOLED [COLOUR]

 

The QHY 268C - Photographic version is one of the most advanced colour cameras for astrophotography. It installs the Sony IMX571, a high performance back illuminated cooled colour sensor with true 16-bit A/D. This translates to a dynamic range of 14 stops for vibrant and natural colours, even in faint or dark nebulae. The pixels have a size of 3.76 µm, ideal for telescopes with different focal lengths.

 

 

The QHY268C comes with all adapters necessary to reach 55mm backfocus, required by most correctors/reducers. The new 2023 version has the same front plate as the monochrome version, reducing the backfocus to 14.5mm. The previous version required a "CAA" dovetail adapter, making the overall backfocus 23.5mm.

 

 

The 268C has three different capture modes:

• #0 Photographic Mode: this is the standard mode for general astrophotography. The read noise rapidly drops between 25-26 (2.7e- at gain 26), ideal for longer exposures. The trade-off at gain 26is lower full well capacity at 27,000 e-, but this can be increased with lower gain settings.

• #1 High Gain Mode: above gain 55 the camera switches to HGC mode with readout noise at 3e-. This mode is ideal for narrowband imaging where long exposures are generally required. 

• #2 Extended Full Well: ideal for objects with bright stars or strong contrast. Full well capacity is highest along the entire gain range.

• #3 2CMS mode: with correlated multiple sampling, readout noise can be better decreased. this mode can effectively raise the dynamic range under Extended Fullwell Mode. 

 

 

Unlike DSLRs, the QHY 268C offers true RAW image output that only records the signal without artefacts. Standard DSLRs have the RAW output option but the file is altered with noise reduction and hot pixel removal, undermining the maximum post processing capabilities and final quality of the image.

The camera has a two-stage TEC cooling system that brings the temperature of the sensor 35C° below ambient for low noise imaging, even in warm climates. The dark current at -20°C is only 0.0005 electron/pixels. In addition, QHYCCD employs a unique thermal noise control technology to reduce CMOS sensor noise to a very low value without affecting the integrity of the raw image. The QHYCCD proprietary technology produces a much better noise reduction than any other astronomy camera in the market. The QHY 268C employs a full anti-dew technology for both CMOS sensor cover glass and the optical window to avoid condensation or ice crystal in the camera. 

The 1GB DDR II memory buffer facilitates the download of images to the computer, especially when USB traffic is high, the writing speed of your computer is slow or occupied with other processes. 

In order to avoid halos around bright stars, the QHY 268C has an AR coated optical window on both sides rather than the common IR/UV cut coating. Also, the protection glass of the sensor is AR coated to maximize light transmission and minimize internal reflections. For a better RGB colour balance, it is recommended to use a UV/IR cut filter.

Every QHY 268C camera is carefully calibrated with a high-precision axis measurement device. Orthogonal sensor placement in the camera body is guaranteed to be flat to the image plane with a precision better than +/-20µm across the sensor edge to edge. This is an enormous advantage especially in fast telescopes such as F/2.8-F/4 astrographs which are very sensitive to tilted sensors.

The QHY 268C has zero amplifier glow no matter how long the exposure is.

 

Specifications

 

 QHY has designed a number of adapter configurations for the 268C. These are included with the camera:

 

 

 

Sensor	Sony IMX571 back illuminated APS-C CMOS - COLOUR
Resolution	26 Megapixels 6280 x 4210
Pixel size	3.76 µm
Sensor size	23.61 mm x  15.83 mm (28.43 mm diagonal)
Quantum efficiency	80%
Exposure range	30µs-3600s
Read noise	1.1e- at high gain; 3.5e- at lowest gain (5.3e- at high gain ; 7.4e- at lowest gain in extended full well mode)
Dark current	0.0005e-/pixel/sec @ -20C
Full well capacity	51,000 e- (more than 75ke- in extended full mode)
Bit rate	Native 16 bit ADC
Frame rate	6 fps at full resolution (16 bits)
Shutter type	Rolling shutter
Cooling	ΔT of 35°C Dual Stage TEC cooler
Memory buffer	1 GByte DDR3
ROI	Supported
Compatibility	Mac, Windows, Linux
Optical window	AR coated (both sides)
AR coating on sensor	YES
Ports	USB 3.0, CFW
Compatibility	Mac, Windows, Linux
Back focus	14.5 mm ±0.3mm
Connections	M54 x 0.75 female thread (embedded in camera dovetail adapter)
Dimensions	Ø 90 mm; ↨ 112.80 mm
Weight	780 g
Power supply	12V 3A  (2.1×5.5 mm connector)
SKU	QHY268C

Included items

 

• QHY 268C PH
• USB 3.0 cable 1.5m
• Power cable (5.5-2.1mm male jack with locking nut to 5.5-2.1mm female jack)
• Power supply 240V to 12V 5A with 5.5-2.1 power jack
• Desiccant Tube (desiccant not included)
• M54 x 0.75 to 2" nosepiece
• Combo adapter kit B4

 

 

Downloads

 

QHY camera drivers

QHY 268C manual

Gallery

 

 Perseus molecular cloud with QHY268C by Steed Yu.