The QHY5III585C colour camera is one of the new generation of QHY5III V2 series planetary guide cameras, offering an enhanced version of its predecessor, the QHY5III485C. It has a high sensitivity in the near infrared similar to that of QHY5III462C, while the dynamic range performance has been greatly improved. It has a 1/1.2-inch large sensor and zero amp glow.
The camera utilizes the Sony IMX585 BSI Sensor, a Sony Starvis II processor that enables high sensitivity and high dynamic range (HDR). It also improves sensitivity in the near-infrared range by approximately 1.7 times compared to the IMX485. The new camera has a large full well capacity of over 30ke-, approximately three times that of the previous generation.
As the QHY team notes, “In this latest generation of sensors, the photodiode portion of the pixel well is physically deeper than in previous sensors, allowing photons of longer wavelengths to penetrate deeper into the substrate. This dramatically increases the sensor’s sensitivity to red and near-infrared (NIR) light. The sensor displays almost equal peak sensitivity to NIR light as it does to light in the visible spectrum.”
One benefit of the back-illuminated CMOS structure is improved full well capacity. 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.
The QHY5III585C colour camera is equipped with a 512MB DDR3 image buffer which can effectively reduce the pressure on computer transmission, a great help for planetary photography which often requires writing a large amount of data in a short period of time.
The camera utilizes the USB3.2 Gen1 Type-C interface. Compared to the USB3.0 Type-B interface used in the previous generation, the Type-C interface has a longer life and is more flexible. The custom interfaces of the previous generation camera has been replaced with a more universal ST-4 compatible guiding interface. Now, even if the guiding cable is lost or damaged, you will be able to easily get a replacement.
The QHY5III585C colour camera is equipped with a status indicator at the back of the camera. If the camera experiences an abnormal status, the multi-colored indicator light will help to determine the situation with different colors signifying different conditions. During normal operation this indicator light is off, so there is no worry about light contaminating the image.
The QHY5III585C colour camera uses a 1.25-inch eyepiece shape design, so it can be added to the 1.25-inch eyepiece without the need for additional interfaces. It also contains the front end of the C-mount, which can be connected to the C-mount lens. Note that this back intercept is slightly less than the standard C back intercept of 17.5 mm. The reason for this design is that a distance of 17.5mm can be achieved through a 1.25-inch spacer.
The QHY5III585C colour camera specifications include:
– CMOS Sensor: Sony IMX585 BSI Sensor
– Pixel Size: 2.9um*2.9um
– Effective Pixel Area: 3856*2180
– Effective Pixels: 8.4 Mega Pixel
– Sensor Size: 1/1.2inch
– Full Well Capacity: 32ke-
– Readout Noise: 0.8-5.5e-
– AD Sample Depth: 12-bit (output as 16-bit and 8-bit)
– Built-in Image Buffer: 512MB DDR3 Memory
– ROI Frame Rate: Full Resolution – 41.5FPS @8BIT, 23.5FPS @16BIT; 1920Lines – 82FPS @8BIT, 47FPS @16BIT; 640Lines -177FPS @8BIT, 106FPS @16BIT
– Exposure Time Range: 11us-900sec
– Shutter Type: Electronic Rolling Shutter
– Computer Interface: USB3.2 Gen1 Type-C
– Guide Port: ST4
– Telescope Interface: 1.25-inch, compatible with CS interface or C interface by changing the front-end connector (An IR-Cut filter and an IR850nm filter are included in the standard version)
– Back Focal Length: 17mm (with adapter);8±0.5mm（without adapter）
– Weight: 90g
You can learn more about the QHY5III585C camera here.