QHY5III568 M/C camera

By Christopher Go – QHY5III568M + Stellarvue SV70 + Coronado SM60

Features

Sensor

The QHY5III568M/C uses a 5.1-megapixel Sony IMX568 Pregius S CMOS sensor with 2472 x 2064 pixels at 2.74um. Pregius is Sony’s trademark name for its global shutter pixel technology for active pixel CMOS image sensors that combine the low-noise performance of CCD with the high-speed and high-precision performance of global shutters. The newly developed Pregius S technology adopts a back-illuminated structure to simultaneously realize a smaller image sensor and a faster frame rate, while still maintaining the high imaging performance of Pregius.

One benefit of the back-illuminated CMOS structure is improved sensitivity. On Pregius S, Sony newly developed an original photodiode structure and light-shielding structure that were optimized for the back-illuminated structure. These greatly improved the sensitivity and saturation properties while also suppressing the noise generation. By utilizing these properties, it is also possible to maintain the image quality while achieving the miniaturization of pixels, which makes a more compact image sensor possible.

Unlike Most CMOS cameras, the QHY5III568M/C camera supports charge-domain binning (FD Binning), which is true hardware pixel binning similar to CCD cameras. In the past, most CMOS cameras used digital binning, which relied on algorithms for binning after the readout process. The disadvantage of this binning method (using 2*2 binning as an example) is that while the signal is amplified by 4 times, it also introduces twice the amount of noise, resulting in only a doubling of the signal-to-noise ratio, and the frame rate is not improved. In contrast, hardware binning does not increase the noise, resulting in a direct 4-fold improvement in the signal-to-noise ratio. Moreover, the frame rate is significantly increased without reducing the field of view by selecting a smaller region of interest (ROI) on the sensor. [NOTE: When the color camera is binned 2×2 it produces a monochrome image] *

Note: In order to activate the Charge Binning function, please select “Read Mode–2×2 FD Binning” instead of the normal binning function included in the software (Taking SharpCap for example). If you are using a color version, please turn off “Debayer Preview” first.

Both the mono and color versions of the QHY5iII568M/C have a global shutter. Unlike the rolling shutter technology used in most CMOS cameras, a global shutter begins and ends the exposure for all pixels in the array at the same time, guaranteeing uniform exposure over the entire image. In the Pregius global shutter design, the pixel comprises a with the excellent low-noise property of CCD and a memory section. The light simultaneously sensed by each photodiode of all pixels is converted to a digital signal and transferred to their respective memory sections before being processed. By processing the simultaneous digital signals all at once, the resulting image has no distortion. This type of shutter is ideal for high-precision applications and is superior to the rolling shutter when imaging moving objects.

High-speed signal processing and high image quality are additional advantages of the sensor design in the QHY5III568M/C. The key to the high speed of CMOS image sensors with Pregius technology is the parallel processing. CMOS image sensors are equipped with A/D conversion circuits, which transform the analogue signal from the pixel to a digital signal. An array of several thousands of these circuits arranged horizontally realizes the high-speed processing by operating simultaneously. In the A/D conversion circuit, the analogue circuit that causes noise has been changed to a different configuration so that it automatically suppresses noise. In this way, the technology both realizes the high speed and low noise in one image sensor.

Curves

Mechanical Dimensions

 

In the box

---