New QHY410C Features

Full Frame, Back-Illuminated

The new QHY410C uses Sony's latest back-illuminated, full frame color sensor.  The IMX410 is essentially a back-illuminated version of the sensor that used in the Nikon D750 and QHY128C cameras.  In addition to BSI, the IMX410 also has larger 5.94 um pixels giving it increases sensitivity of extended objects in low light.  The IMX410 is expected to be Sony's most sensitive full frame color sensor for astrophotography. 

Similar in body size and design to the QHY268C, the QHY410C is available in two versions, a photographic version, the QHY410C-PH and a professional version, the QHY410C-PRO. 

The QHY410C-PH (Photographic Version) is USB 3.0 only with 1GB DDR3 memory (32-bit data bus).  It can output 15 frames per second, full resolution, 8-bit images or 7.5 frames per second, full resolution, 16-bit images. 

The QHY410C-PRO (Professional Version) is USB3.0 plus 2 x 10G fiber optic ports with 2GB DDR3 memory.   It can output 19.2 frames per second, full resolution, 16-bit images or 40 frames per second, full resolution, 12-bit images.

There is no difference in image quality between the Photographic version and the Professional version.  The Photographic version QHY410C-PH is ready for delivery now.  The QHY410C-PRO price and specifications will be announced in coming weeks.

High Full Well Capacity - High Dynamic Range

One benefit of the back-illuminated CMOS structure is improved full well capacity. This is particularly helpful for sensors with small pixels.  When back-illumination is combined with somewhat larger pixels, the full well capacity and cynamic range are improved dramatically.  The QHY410C has a full well capacity of 120k electrons!  With its low read noise this produces a dynamic range greater than 17,000:1 or more than 14 STOPS.  Moreover, the dynamic range remains fairly uniform even at higher gain settings (see the graphs below).

Low Read Noise

The QHY410C is capable of only 1.1 electron of read noise at high gain and fast 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 read noise facilitates taking more short exposures and combining them rather than needing fewer long guided exposures to get the ideal signal to noise in the final image.  Short exposures allow grading of frames to be used, with the ability to discard the occasional guiding glitch instead of having a mount bump or airplane ruin an otherwise carefully guided long exposure.     

Back-Illuminated, High QE, Twice the Sensitivity of Front Illuminated Sensors

Sony's Exmor R back-illuminated technology produces sensors that Sony estimates are twice as sensitive as similar front illuminated sensors.  QHYCCD tests have borne out this claim.  Additionally, Sony sensors are well known for their low dark current.  QHYCCD's proprietary thermal noise reduction technology and the QHY40C's dual-stage regulated thermoelectric cooling further reduce dark current to extremely low levels for clean, long duration exposures when required.

Best Match for Longer Focal Length

The 5.94 um pixels of the QHY410C will subtend a half arcsecond FOV at approximately 2500mm of focal length (or 1 arcsecond at 1250).  This, with its 35mm format sensor and high sensitivity make it ideal for imaging in color with longer focal length scopes.