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QHYCCD QHY268M 26MP Cooled APS-C Mono CMOS Astrophotography Camera - QHY268M-PH

2 In Stock - Ships Today if Ordered by 2pm EDT! (Mon - Fri)
Camera
QHYCCD
QHY268M-PH

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 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 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.

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.

 

Features

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.

 

USB Re-connection by 12V Power on/off

The 268 camera’s USB interface to the computer can be connected or disconnected by turning on and off the camera’s 12V power, without the need to plug and unplug the USB cable. This technology enhances the controllability of the camera when used in a remote station.  You only need to remotely control the 12V power supply of the camera, or the power of the camera AC adapter, to achieve remote USB connecting and reconnecting of the camera.

 

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 QHY600 / 268C uses an innovative suppression technology that can significantly reduce the apparent level of such noise.

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 QHY600 can achieve an extremely large full-well charge value of nearly 80ke- and the QHY268C can achieve nearly 75ke-.  Greater full-well capacity provides greater dynamic range and large variations in magnitude of brightness are less likely to saturate.  The QHY600 / 268C have three readout modes with different characteristics.


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.

Specifications
Model QHY268M QHY268C
COMS Sensor SONY IMX571 M SONY IMX571 C
Mono/Color Mono Color
FSI/BSI BSI
Pixel Size 3.76um x 3.76um
Effective Pixel Area 6280*4210 (includes the optically black area and overscan area)
Effective Pixels 26MP
Sensor Size APS-C
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 USB3.0 Port:
Full Resolution  6.8FPS  @8BIT         6FPS @16BIT
2048lines         13.6FPS  @8BIT     11.5FPS@16BIT
1080lines         25.4FPS  @8BIT     19.5FPS@16BIT
768lines           35FPS     @8BIT        25FPS@16BIT
480lines           50FPS     @8BIT        34FPS@16BIT
Readout Noise 1.1e- High Gain,

 

3.5e- Low Gain

(5.3e- to 7.4e- in extended full well mode)

Dark Current -20C,0.0005e /pixel/sec

 

-10C,0.001e /pixel/sec

Exposure Time Range 30us-3600sec
Unity Gain* 0(PH Mode)

 

30(Extended Fullwell Mode)

 

*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.

 

Amp Control Zero Amplifer Glow
Firmware/FPGA remote Upgrade Fully support via Camera USB port
Shutter Type Electronic Shutter
Computer Interface USB3.0
Built-in Image Buffer 1Gbyte DDR3 Memory
Cooling System 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

Optic Window Type AR+AR High Quality Multi-Layer Anti-Reflection Coating
Anti-Dew Heater Yes
Humidity Sensor* Yes No
Telescope Interface Support M54 and M48 (with standard adapters ) M54/0.75 (with CAA)and M48 (with standard adapter)
Back Focal Length QHY268M: 12.5mm (with CAA)
If used with the QHY filter wheel, the actual calculated intercept is 12.5mm.The actual BFL (the intercept from the CMOS chip to the top of the camera) is 14.5mm. Since most uses will match CFW with monochrome cams, please take 12.5mm as major reference. Check the mechanical drawing below for details.
Note 14.5mm rear intercept does not include adapter thread, which must be used with adapters of various sizes through the top 6 screw holes.
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.
Weigth 855g 780g
Readout Modes and Curves

Multiple Readout Modes is a new function for newer QHY Cameras.  Different readout modes have different driver timing, etc., and result in different performance. The QHY268 currently has four readout modes, and more modes will be added in the future. These readout modes are currently supported in the QHY ASCOM Camera Driver, SharpCAP software and the N.I.N.A software.

Readout Mode #0 (Photographic Mode). In this mode there is a drop in the noise between Gain 25 and Gain 26.  We recommend setting the Gain to 26 to begin.  At this setting the full well is 27ke- and readout noise is 2.7e-.  For every long exposures you can lower the gain from this point to increase the full well capacity.

Readout Mode #1 (High Gain Mode).  Please note there is a HGC/LGC switch point at gain55 to gain56. Gain0-55 uses LGC and Gain55-100 uses HGC.

Readout Mode #2 (Extended Fullwell Mode).

Now QHY600 adds #3 mode Extend Fullwell 2CMSIT (yellow curve). The advantage of this mode is that it has the same full well value and system gain as the #2 mode Extend Fullwell, but the read noise is reduced by about 1.3 times.

This function needs to be used with 2020.6.26 or newer SDK. If your software cannot display this mode, please download the QHYAllInOne installation package to update the SDK in the software.

 

 


 

Absolute QE

Relative QE

Mechanical Dimensions
Accessories and Match
Combos and Adapters

Now we only have one APS-C Mono model—QHY268M.Fiirst there’s no doubt that 2-inch filters are large enough to cover the whole sensor area, but they’re not cheap enough. With a rough estimate, we think 36mm filter can be matched with scopes whose focal ratio are smaller than f/5 (f/4 worth a try, too). However, if your scope has a large focal ratio like f/2.8, we suggest you think carefully before using 36mm filters.

Model BFL Consumed Filters Supported
QHY268M 12.5mm
CFW3M-US 17.5mm 7 position

 

36mm unmounted

CFW3L 21.5mm 7 position

 

2inch mounted/50mm unmounted

OAGM 10mm

 

Generally speaking, there’s no need for an OSC (one shot colored) camera to match filter wheel. If there’s any special needs, please refer to mono cam combos and choose the corresponding filter wheel. All OSC cams use OAG M if needed.

Model BFL Consumed
QHY268C 17.5mm+6mm (CAA)
B1: Connecting MPCC that requires 55mm BFL and M48 interface to Camera with CFWL and OAG

Note:

  1. If your MPCC requires a BFL different from 55mm, this adjustment can be made by selecting the appropriate spacer between the MPCC and the OAG.  For example, an MPCC that requires 57.5mm can be used instead by adding a spacer ring or rings that add 2.5mm of BFL. to the diagram above.
  2. If you don’t use an OAG, you can use a 10mm spacer adapter in the adapter kits to replace the original position of OAG.
  3. Put OAG at the position next to the M48 Output to make both main cam and guiding cam focused.

 

B1: Connecting MPCC that requires 55mm BFL and M48 interface to Camera with CFWL and OAG

B1: Connecting MPCC that requires 55mm BFL and M48 interface to Camera with CFW3M-US Only

B2: Connect Canon EF lens to Camera with filter Wheel

B3: Connect Nikon F Lens to Camera with Filter Wheel

Note: The current Nikon adapter used here is different from the 10mm adapter we used to provide. Now it has a back focal length increment of 12mm.

 

D1: Connecting MPCC with 55mm BFL and M48 interface

If you don’t use an OAG, please use 10mm adapter in the adapter kits to fill the original position of OAG.

D2: Connecting Canon EF Lens

D3: Connecting Nikon F Lens

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