QHY600 Back-Illuminated, 60 Megapixel,
Full Frame Format, 16-bit, Cooled CMOS Camera
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. However, for years we have only seen the 4/3-inch, front-illuminated, monochrome cameras (QHY163M) with QE of about 60%, and one-inch, back-illuminated, monochrome cameras (QHY183M) with higher QE. Although these sensors are quite good and very suitable for beginners, they are still smaller than the full frame (35mm format) sensors desired for more serious deep sky astrophotography. Also, both of these sensors have 12-bit A/D. To achieve 1e- of read noise you must increase the gain and lose some dynamic range in the process, or you use low gain and lose some precision in sampling and greyscale levels.
2. The Professional version may have more on-camera DDR3 memory than photograph version.
3. The professional version has rich, external, expandable I/O signals as well as a rich resource that allow the user to customize the FPGA inside the camera.
4. The Professional version is more expensive than Photographic version.
5. The Professional version has a longer body to accommodate the length of the optical fiber interface.
The new QHY600 is about to change all of this.
The QHY600 uses the latest SONY back-illuminated sensor, the IMX455, a full frame (35mm format) sensor with 3.76um pixels and native 16-bit A/D. This sensor is available in both monochrome and color versions. The QHY600 ends the days of non-16bit CMOS cameras and it ends the days non-full frame (and larger) monochrome CMOS cameras.
The QHY600 camera will be available in two versions: a scientific, or Professional version (QHY600U3G20) and a Photograph version (QHY600U3). The differences between these two versions include:
1. The Professional version has a high-speed fiber interface and USB3.0 interface. The Photographic version has only a USB3.0 interface.
QHYCCD is offering an Early Bird price for the QHY600. A limited quantity of special QHY600 cameras are available for USD5000. The Early Bird version of the camera has the hardware design of the Professional model, but the functions of the Photographic version. For example, the Early Bird version will have sockets for both Ethernet and USB3.0 but only the USB socket is active. User who buy the Early Bird version can upgrade it to the full Professional version QHY600U3G20 by paying the difference in price. （The amateur photography version have no chance to upgrade into profesional version） The Early Bird version also includes a free set of the QHYCCD 0.5mm-27.5mm spacers for precise and solid back-focus adjustment in a variety of optical train configurations. Early Bird purchasers can also order a QHYCFW3L (7-position, 2-inch, 50mm) or QHYCFW3XL (9- position, 2-inch, 50mm) motor-driven filter wheel with the QHY600 camera at 10% off the list price of the filter wheel.
Comparing the IMX455 and KAI11002 35mm Format Monochrome Sensors
Recently, Sony released several new CMOS sensors, including the 60 Megapixel, full frame, IMX455. QHYCCD uses this sensor in its new QHY600 cameras. The question then is how does this sensor compare with the ubiquitous KAI11002? We know that the KAI-11000/11002 is an interline CCD sensor and the IMX455 is a CMOS sensor. But what are the advantages of the new IMX455 compared to the KAI11002? See the comparison at https://www.qhyccd.com/index.php?m=content&c=index&a=show&catid=23&id=262
1. Does QHY600 support hardware binning?
The CMOS sensor itself has some binning function but it should not be the hardware binning (FD binning). And also the binning in the sensor is based on the location of the bayer color . it means it will binning with the same position of the same color.And for monochrom QHY600 sensor, it is still use such a position to do binning. So we think it is not a good solution for the monochrom binning.
And since the very low readout noise of the QHY600, so the digital binning may bring more advantage. First , it can increase the fullwell. Binning at 2*2 will gives four times of the fullwell. Second, it will increase the AD sample depth. Binning at 2*2 will give 18bit data range. For readout noise, the N*N digital binning will cause the readout noise become SQR(N*N）= N times. For example, if the readout noise is 1.9e at 1*1 binning. The 2*2 digital binning readout noise will become 1.9*SQR(2*2)=3.8e.
2.What is the benefit of the Fiber Interface
Normally speaking the fiber interface is for the requestment of the professional obs. It will give the following advantages than USB3.0
3. What's the absolutely QE of QHY600？
SONY does not release the official absolutely QE curve of the sensor. There is only a relativity QE graph. (Can be found on QHY600 specification page). But we did a some experiment of testing the absolutely QE of QHY600 by comparing with a known QE sensor. . The article can be found at https://www.qhyccd.com/index.php?m=content&c=index&a=show&catid=23&id=261 The current test results shows a very high QE, it looks too high. We will find more sensor to do this work again.
- Higer data rate. One 10Gigabit Fiber can transfer maxium 10Gbps data. The actual data rate can get about 800MBytes/s. While the USB3.0 is 5Gbps and the actaully data rate is about 350MByte/sec. Use the two 10Gigabit fiber can get about 1.6GBytes/s speed. The IMX455 sensor has the high speed mode like the 10FPS 14bit full resolution mode and 30FPS 8K VIDEO mode. The data rate of these modes are much more than USB3.0. These mode can be well supported by QHY600's 2*10Gigabit filber solution
- Very long transfer distance. The fiber can hundreds times longer than USB3.0. USB3.0 can only transfer 3meter to 5meter. For more longer distance, it need the extender cable but can just get 10meter to 15meter. While the Fiber can transfer 300meter directly by default optic module comes with the QHY600. And if with the long distance optic module , it can trasfer up 40km.
- Solid stable and no affected by EMI. One major factor cause the camera hangs is the EMI issue. The USB3.0 transfer maybe get affect by the EMI in the transfer patch. Like the static and other high power device emitted. The EMI will cause the transfer data packet get CRC error and cause image lost. The USB cable more longer, it is more easy to get this problem. Light can not be affected by the EMI. So with the fiber transfer it will get everything very stable.
4. How to set the gain, offset and readmode at the first using
For first using, we recommand this value: readout mode = #0 gain=26 offset=10. Here is an article for gain/offset setting at https://www.qhyccd.com/index.php?m=content&c=index&a=show&catid=23&id=22
5. Meet "Out of Memory"
Please make sure the QHYCCD SDK had been update to the last version. 2019.10.8 (V6.0.3) or later. The previous two version has a memory leak bug and it will cause more memory lost . And if it is still out of memory, it maybe the memory not enough in 32bit memory space. Since the 61mega pixels, the QHY600 require big memory. The SDK will use about more than twice of the size of the image data (in mono version it is 120MB per frame. so SDK need about 300MB, for color version it is 360MB per frame , so the SDK need about 800MB) And the image acquire software need one or more . For x86 system , the totally memory space is 4GB, many other X86 software will take this space so it maybe not enough memory there. We recommend to use the x64 software, like the X64 SharpCAP, X64 N.I.N.A software. If you are using the X86 software. it is best to close other software to reduce the 4GB space usage