QHY268M - PHOTOGRAPHIC COOLED [MONOCHROME]

 

The QHY 268M contains the Sony IMX571, a high performance back illuminated cooled monochrome sensor with true 16-bit A/D. This translates to a dynamic range of 14 stops. The pixels have a size of 3.76 µm which is ideal for telescopes with different focal lengths.

 

From 2023 onwards, the QHY268 series has a redesigned front plate with shorter backfocus, 14.5mm compared to the previous 17.5mm. The QHY268M comes with all adapters necessary to reach 55-56mm backfocus, required by most correctors/reducers. 

The 268M has four different capture modes:

• #0 Photographic Mode: this is the standard mode that can be used for general astrophotography. The readout noise rapidly drops between 25-30 (2.5e- at gain 30), ideal for longer exposures. The trade-off at gain 30 is a lower full well capacity at 30,000 e-. In fast telescopes (f/2.2 - f/4) the gain can be set to zero to use the maximum full well capacity (75,000 e-).

• #1 High Gain Mode: the readout noise is much lower at 3e- between gain 0 and 55. 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 the 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 DSLR cameras, the QHY 268M Pro offers true RAW image output that only records the signal without artefacts. Standard DSLR's have RAW output but the file is altered with noise reduction and hot pixel removal, undermining post processing capabilities and final image quality.

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 unique thermal noise control technology to reduce CMOS sensor noise to a very low value without affecting the integrity of the raw image. This proprietary technology produces much better noise reduction than any other astronomy camera on the market. The QHY 268M employs a full anti-dew technology for both CMOS sensor cover glass and the optical window to avoid condensation or ice crystals. 

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. 

To avoid halos around bright stars, the QHY 268M has an AR coated optical window on both sides rather than the common IR/UV cut coating. The glass of the sensor is AR coated to maximize light transmission and minimize internal reflections.

Every QHY 268M camera is carefully calibrated with a high-precision axis measurement device. Orthogonal placement of the sensor in the camera body is guaranteed to be flat to the image plane with a precision better than +/-20µm across the sensor, from edge to edge, so there is no need to adjust the camera tilt. 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 268M has zero amplifier glow no matter how long the exposure is.

 

Specifications

 

Adapters included with the camera necessary to reach a backfocus of 55-56mm.

 

Sensor	Sony IMX571 back illuminated APS-C CMOS - MONOCHROME
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 GB 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
Connections	M54 x 0.75 female thread (embedded in camera dovetail adapter)
Dimensions	Ø 90 mm; ↨ 109.33 mm
Weight	855 gr
Power supply	12V 3A  (2.1×5.5 mm connector)
SKU	QHY268M

 

 

Included items

 

• QHY 268M
• 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 240 to 12V 5A with 5.5-2.1 power jack
• Desiccant Drying Tube (desiccant not included)
  
• M54 x 0.75 to 2"adapter (2.5mm optical thickness, M48 x 0.75 internal thread for standard 2" filters)
  

Combo B1:

• Spacers for QHY medium accessories - 10mm, 4mm, 3mm, 1mm
  
• Medium accessory to M48 adapter - 5mm
  
• Screws - 8x M3 8mm, 8x M3 23.5mm, 8x M3 27.5mm, 8x grub screws 

 

 

Downloads

 

 

 

 

Guide to installing QHY and ASCOM drivers for QHYCCD cameras.

 

QHY camera drivers

QHY 268M manual

Gallery

 

 

Carina Nebula by Stefano Salvi | SkyWatcher Quattro 200 f/4, Saxon AZ-EQ6, QHY268M Pro, Antlia 3nm SHO Ultra Narrowband filters, Prima Luce Lab Sesto Senso 2.

 

 

Tarantula Nebula by Caleb Kam | QHY268M with Antlia 3nm Pro H-alpha & OIII filters.