QHY268 BSI Cooled Medium Size APS-C Camera
Ultra High Resolution, 26 Megapixels, APS-C format
QHY268 is a 26 Megapixel back-illuminated cooled color CMOS camera with 16-bit A/D and 3.76um pixels. The QHY268C is available in both a monochrome and a color version. The sensor size is 23.5mm x 15.7mm (28.3mm Diagonal)
The QHY268M is the first monochrome CMOS camera with an APS-C sensor. The chip has the same functions as the flagship QHY600M:
- USB Re-connection with 12V ON/OFF
- Extended Full Well and Multiple Read Modes
- Random thermal noise suppression
- 20Gb optical fiber transmission (PRO-Version, under development)
- 1GB / 2GB oversized DDR3 memory
- Large programmable FPGA (only PRO)-Version, under development
- Water-cooled option
The high-resolution cooled, monochrome APS-C Camera uses a 26 Megapixel Sony IMX571 Back Iluminated Sensor with 16-bit A/D and 3.76um pixels. The QHY268 will be available as photo version and pro version (under development). Image quality is identical between the two models.
Native 16-bit A/D, 65536 Levels
The QHY268 is the CMOS camera with 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, 16-bit A/D provides higher sampling resolution. System gain is less than 1e-/ADU with low noise and no sampling error.
Full Well Capacity of 60 ke- to > 87 ke- Low Gain Mode
One benefit of the back-illuminated CMOS structure is improved full well capacity. This is particularly helpful for sensors with small pixels.Even with unbinned 3.76µm pixels the QHY268C has a full well capacity of >60ke-. By using one of the binning modes, this can be increased to > 87 ke-.
Ultra-Low Read Noise of less than 2 Electrons at High Gain
The QHY268 PHOTO Version (M and C) has less than one electron of read noise at high gain and 6 FPS high readout speed. The QHY268C PRO has only one electron of read noise at high gain and 6,8 FPS high readout speed.
One electron of read noise means the camera can achieve a SNR>3 at only 3 to 4 photons. This is perfect performance when conditions are photon limited, i.e., short exposures, narrow band imaging, etc., making this large area sensor ideal for sky surveys and time domain astronomy.
Low Dark Current, TE Cooling, Round Body
The QHY268 has extremely low dark current using SONY's Exmor BSI CMOS technology. In addition, the camera uses QHYCCD's proprietary thermal noise reduction technology and 2-stage TE cooling to reduce the dark current noise to extremely low levels.
Best Match for RASA System
The round body and sensor size make this camera ideal for RASA and Hyperstar systems.
The Photographic and Professional Model of QHY268 M/c
Choose between three models: The Photographic Model QHY268 M/C PHOTO or the Professional Model QHY268C PRO. Image quality is identical between the two models.
Photographic Modell QHY268 M/C PH (PHOTO: Professional Model QHY268M**/C PRO:
- 6 FPS, full frame, 16-bit images
- 6.8 FPS, full frame, 8-bit image
- Support for ROI at higher frame rates
- 1 GByte DDR3 memory
- 2×10Gigabit optical fiber interface
- Programmable trigger in/out
- Advanced timing interface for GPS
- 6,9 FPS, full frame, 16-bit images
- Support for ROI at higher frame rates
- Customizable FPGA
- 2 GByre DDR3 memory
Two 5m double fibre optic cables and two optical fibre modules are included with the camera.
**The QHY268M Pro Version is expected to be available this year.
4 Selectable Readout Modi (#0 to # 03)
Readout Mode is a new function for the QHY cameras. Different Readout Mode have different driver timing etc and lead to the different performance results. Each readout mode has its advantages and disadvantages. QHY600/QHY268 currently has three readout modes. QHYCCD may add more modes in the future. The Readout mode currently supported by QHY ASCOM Camera Driver and SharpCAP software and the N.I.N.A software. You can find the list box in the software.
Mode # 0
This is the standard readout mode for most applications. A a gain of 25 to 26, the readout noise is only about 7 from 2,5 e-. The readout noise is doesn't change much for a gain between 0 and 25 as well as for a gain between 26 and 60. That's why most users will probably chose either gain 0 or gain 26, because the full well capacity decreases at a higher gain than 26, as well as the dynamic range. At fast optics like f/2 (e.g. RASA), a gain of 0 will probably be most useful. For slower telescopes under a dark sky (and thus longer exposure times), gain 26 is recommended, so that you can profit of the lower readout noise.
# 1 – High-Gain-Mode
This mode is characterised by a low readout noise and a slightly smaller full well capacity. Just like in the standard mode #0, there is a sweet spot for high or low gain. In this mode, the readout noise goes from 3,5 e- to 1,5 e- between gain 55 and 56.
# 1 – Expanded Fullwell-Mode
This mode achieves the highes full-well-capacity. The readout noise is almost independent from the gain setting approximately always at 7 e-. The dynamic range is almost always between 13 and 14 f-stops.
Mode # 3
Mode # 3 is very similar to mode # 2, but at a constantly lower readout noise between 4,5 e- and 5,5 e- (instead of 7,5 e- in mode # 2).
Here are the plots for the different modes:
Further detailed information can be found the website of QHYCCD :
If you have any further questions, please send us an email to kontakt (at) baader-planetarium.de.
|Manufacturer SKU (#)||QHY268PH M|
|Net weight (kg)||0.98|
|Sensor Typ||Back Illuminated|
|Sensor||SONY IMX571 APS-C BSI CMOS Sensor|
|Sensor Size||APS-C Format|
|Sensor Diagonal||28,3 mm|
|A/D Conversion||Native 16-bit|
|Resolution||6280*4210 (includes the optically black area and overscan area)|
|Pixel Size||3.76um x 3.76um|
|Back Focus Distance||17.5mm（±0.3）/ Mono-Version 12,5mm （±0.5）|
|Exposure Range||30us - 3600sec|
|Full Well Capacity||> 60ke- bis > 87ke- (depending on the readout mode)|
|Read Noise (RMS)||2,0 to 3,5 e- (High Gain), 4,5 to 7,5 e- (Low Gain)|
|Dark Current @ -20C||0.0005e-/p/s @ -20C, 0.001e-/p/s @ -10C|
|Built-in image Buffer||1 GByte DDR3 memory|
|Maximum Frame Rate||Full Resolution 6.8FPS @8BIT, 6FPS @16BIT|
|User Interface||USB 3.0|
|Cooling||Dual Stage TEC cooler（-35C below ambient）|
|Optical Window||AR+AR High Quality Multi-Layer Anti-Reflection Coating|
|Shutter||Electronic Rolling Shutter|
|Included Accessories||Power supply included in the scope of delivery|