QHY 268M 26 MP Photographic CMOS APS-C Monochrome Astronomy Camera

• Back Focal Length: 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 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.
• Telescope Interface:Support M54 and M48 (with standard adapters )

1. Ultra High Resolution: 26 Megapixels, APS-C format

The QHY268M is a 26 Megapixel cooled, back-illuminated, monochrome CMOS camera based on the Sony IMX571 sensor with native 16-bit A/D and 3.76um pixels.

2. Native 16-Bit: On-chip 16-bit A/D, 65536 Levels

The Sony IMX571 sensor has on-chip 16-bit A/D for highest resolution of greyscale. 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. At high gain, the camera yields close to 1e-/ADU with low read noise and no sampling error.

3. High Dynamic Range: 51ke- Full Well at 3.76um, 75ke- in extended 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 3.76um pixels the QHY268M has a full well capacity of 51ke-. QHY268M also offers a unique read mode up to 75ke per pixel. When binned 2x2 to 7.5um the full well is 176ke- and when binned 3x3 to 11um the full well is 396ke-.

4. Ultra Low Read Noise: 0.7e- Noise at High gain, 3.5e- Noise at Low Gain

The QHY268M has only 0.7 electron of read noise at its highest gain and 6.8 FPS at full resolution readout speed. One electron of read noise means the camera can achieve a SNR>3 at only 4 to 6 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

5. Back-Illuminated, High QE: Very Low Dark current, Electronic Shutter, Round Body

The back-illuminated Sony Exmor sensor has about twice the QE of similar front illuminated sensors. The QHY268M has extremely low dark current using SONY's Exmor BSI CMOS technology (only 0.0005e/pixel/sec @ -20C). 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.

In general, a fan-blade mechanical shutter may fail after several hundred thousand cycles and is subject to intermittent problems in very cold weather. The advantage of an electronic shutter over a mechanical shutter is high reliability and stability when the observer takes a large number of images.

The round body and sensor size make this camera ideal for Hyperstar and RASA systems. The camera has a USB3.0 interface to the computer.

6. Built-In Buffer for Reliable Data Transfer

2GB Image Buffer: In order to get smooth uninterrupted high speed transfer of data, the QHY 268C has a large 2 GB DDR3 memory buffer.

7. Short 12.5mm Backfocus

The mono camera is expected to be used with a filter wheel so the mono version uses the ultra short back focus design (12.5mm) to facilitate this configuration.