DISCOVER NEW HORIZONS
C/2025 A6 (Lemmon)
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Imaging Camera QHY600
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Total Integration 12min
L: 450sec
R: 90sec
G: 90sec
B: 90sec
Astrophotographer
Michael Jäger,
Gerald Rhemann G00
QHY268M Pro I
QHY268M Pro I is a scientific CMOS camera specially designed for scientific using with advanced qualities and functions.With a SONY IMX571 APS-C format CMOS sensor inside. 26mega pixels, Back-illuminated, native 16BIT ADC. QE is up to 91% and readout noise is as low as 1.1e Even with a 3.76um pixel size, it has a big full-well up to 75ke.
It has extremely low thermal noise 0.0005e/pixel/sec @ -20C, ZERO amplifier-glow performance, It has a maximum frame rate of 6.8FPS@16bit full resolution. QHYCCD IMX571.SONY IMX571/16bit/26Mpixels/BSI/APS-C Format. QHY268PRO has both USB3.0 and 2*10Gbps optical fiber interface. It has a 2GB big DDR3 memory buffer. It has the 6pin GPIO port support complex Trig-In and Trig-Out signal. It can connect with QHY GPS-BOX to get the high-precision GPS timestamp onto the image head.
Currently we only have the monochrome QHY268M Pro I as standard model. If you have requirement for color version (QHY268C Pro), please contact QHYCCD for customization.
Overview
QHY268M Pro I has SONY IMX571 APS-C format CMOS sensor inside. 26mega pixels, Back-illuminated, native 16BIT ADC. QE is up to 91% and readout noise is as low as 1.1e Even with a 3.76um pixel size, it has a big full-well up to 75ke. It has extremely low thermal noise 0.0005e/pixel/sec @ -20C, ZERO amplifier-glow performance, It has a maximum frame rate of 6.8FPS@16bit full resolution.
*PCIE Card Kit is NOT included in QHY268Pro product.
Native 16 bit A/D: The new Sony sensor has native 16-bit A/D on-chip. The output is real 16-bits with 65536 levels. Compared to 12-bit and 14-bit A/D, a 16-bit A/D yields higher sample resolution and the system gain will be less than 1e-/ADU with no sample error noise and very low read noise.
BSI: One benefit of the back-illuminated CMOS structure is improved full well capacity. 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.
TRUE RAW Data: In the DSLR implementation there is a RAW image output, but typically it is not completely RAW. Some evidence of noise reduction and hot pixel removal is still visible on close inspection. This can have a negative effect on the image for astronomy such as the “star eater” effect. However, QHY Cameras offer TRUE RAW IMAGE OUTPUT and produces an image comprised of the original signal only, thereby maintaining the maximum flexibility for post-acquisition astronomical image processing programs and other scientific imaging applications.
Zero Amplify Glow: This is also a zero amplifer glow camera.
Cooling & Anti-dew Control: In addition to dual stage TE cooling, QHYCCD implements proprietary technology in hardware to control the dark current noise. The optic window has built-in dew heater and the chamber is protected from internal humidity condensation. An electric heating board for the chamber window can prevent the formation of dew.
Sealing Technology: Based on almost 20-year cooled camera design experience, The QHY cooled camera has implemented the sealing control solutions. The sensor itself is kept dry with our silicon gel tube socket design for control of humidity within the sensor chamber. By the way, there’s no oil leaking.
General Introduction of Pro-grade Scientific Cameras
Compared to astrophotographic products, the scientific grade “Pro” grade vesion has more interfaces, more functions, and higher quality to cater for the complicated needs including but not limited to: Sky Survey, Astronomical Photometric, high-resolution LCD/OLED screen inspector/color calibration. All-sky camera. Scientific Measurement, DNA sequencer, Spectrum Instrument.
A Pro grade scientific grade camera has the following interfaces or functions.
USB3.0
USB3.0 is a very popular interface and very easy to use. USB3.0 can not support a transfer distance of more than 3meter. If you want to get a long-distance under USB3.0, QHYCCD supplies the optional 5meter and 10meter USB3.0 extender cable with a built-in amplifier.
2*10Gbps Fiber Interface
The built-in 2*10Gbps fiber socketcan work with the QHYCCD PCIE2.0x8 data grabber card. The fiber interface is for the requirement of the professional obs. It will give the following advantages than the USB3.0 interface. Then what is the benefit of the Fiber Interface?
- Higher data rate. One 10Gigabit Fiber can transfer maximum 10Gbps data. The actual data rate can get about 800MBytes/s. While the USB3.0 is 5Gbps and the actual data rate is about 350MByte/sec. Use the two 10Gigabit fiber can get about 1.6GBytes/s speed.
- Very long transfer distance. The fiber is hundreds of times longer than USB3.0. USB3.0 can only transfer 3meter to 5meter. For longer distances, it needs the extender cable but can just get 10meter to 15meter. While the Fiber can transfer 300meter directly by default optic module; with the long-distance optic module, it can transfer up to 40km.
- Solid stable and no affected by EMI. One major factor that causes the camera to hang is the EMI issue. The USB3.0 transfer maybe gets effect by the EMI in the transfer patch. Like the static and other high-power device emitted. The EMI will cause the transfer data packet to get a CRC error and cause the image loss. A long USB cable is easier to get this problem. Light can not be affected by the EMI. So with the fiber transfer, it will get everything very stable.
GPIO
There is a 6pin GPIO socket on the camera backside. It can be configured into different modes, or customized as the user requests to meeting more complex timing by re-programming the FPGA.
Liquid Cooling (Customization)
Compared with air cooling, liquid cooling has the following important advantages. If any interst, please contact QHYCCD in advance for customization.
No vibration. Air-cooling requires the use of a fan inside the camera that may induce small vibrations. Even the highest quality fan cannot avoid some effect on the FWHM (full width at half maximum) of stellar images on certain telescopes. Long focal length optical systems are more sensitive to this effect. However, water cooling achieves temperature reduction through the slow flow of water. There is no moving mechanical component to cause vibration of the camera, eliminating any negative effect on the image.
No hot air turbulence. For optical systems like RASA and Hyperstar where the camera is placed at the secondary position, air turbulence is not generated. When an air-cooled camera is installed in front of the optics, the hot air generated by the air-cooled system passes through the optical path and can generate seeing effects. Water cooling does not produce hot air discharge. The heat is carried away by the liquid so there is no such effect.
Greater Cooling Delta T. With water cooling, the maximum cooling temperature is about 10 degrees Celsius lower than the maximum temperature achieved with air only （About 45 degree below ambient).
Advanced Functions
Multiple Readout Modes
Multiple Readout Modes are special for QHY 16-bit Cameras (QHY600/268/461/411). Different readout modes have different driver timing, etc., and result in different performance. See details at “Multiple Readout Modes and Curves” Part.
Random change thermal noise suppression function
You may find some types of thermal noise can change with time in some back-illuminated CMOS cameras. This thermal noises has the characteristic of the fixed position of typical thermal noise, but the value is not related to the exposure time. Instead, each frame appears to have its own characteristics. The QHY600/268/461/411 use an innovative suppression technology that can significantly reduce the apparent level of such noise.
UVLO Protection
UVLO（Under Voltage Locking) is to protect the electronic device from damage caused by abnormally low voltages.
Our daily life experience tells us that the actual operational voltage of an electrical device must not significantly exceed the rated voltage, otherwise it will be damaged. For such precision equipment as cameras, long-term work at too low input voltage can also be detrimental to the working life of the camera, and may even make some devices, such as power manager, burn up due to long-term overload. In the all-in-one driver and SDK after 2021.10.23 stable version, the camera will give a warning when the input voltage of the camera is below 11V.
Optimizing USB Traffic to Minimize Horizontal Banding
It is common behavior for a CMOS sensor to contain some horizontal banding. Normally, random horizontal banding can be removed with multiple frame stacking so it does not affect the final image. However, periodic horizontal banding is not removed with stacking so it may appear in the final image. By adjust the USB traffic in Single Frame mode or Live Frame mode, you can adjust the frequency of the CMOS sensor driver and it can optimize the horizontal banding appeared on the image. This optimized is very effective to remove the periodic banding in some conditions.
A typical Periodic Horizontal Noise under certain USB_TRAFFIC values.
After Adjusting the USB Traffic to avoid the periodic horizontal noise.
Reboot the camera by power off and on
The camera is designed to use the +12V to reboot the camera without disconnecting and reconnecting the USB interface. This means that you can reboot the camera simply by shutting down the +12V and then powering it back on. This feature is very handy for remote controlling the camera in an observatory. You can use a remotely controlled power supply to reboot the camera. There is no need to consider how to reconnect the USB in the case of remote control.
Multiple Readout Modes and Curves
Monochrom’s Spectrum Response Curve. The curve is based on SONY’s datasheet. In the datasheet, it is the normalized curve QHYCCD test it by comparing with an known QE CCD sensor. And get this curve. This curve is only a reference. QHYCCD does not guarantee this curve is correct.
Color version (Normalized Response Curve from SONY datasheet).
Multiple Readout Modes are special for QHY 16-bit Cameras (QHY600/268/461/411). Different readout modes result in different performance. These readout modes are currently supported in the ASCOM, SharpCap and N.I.N.A.
Photographic DSO Mode (Mode #0)
This mode is suitable for most DSO imaging situations. Since there is a drop in the noise between Gain 25 and Gain 26 (unity gain), we recommend it as default gain setting; however, gain0 is also good enough for a 16-bit sensor.
High Gain Mode (Mode #1)
This mode is something like double native iso of some new digital cameras, whose danamic range can greatly incerase at the vary high iso value, like iso800, iso3200, etc. The high gain mode provide such improvement for QHYCCD 16bit cameras. We recommend you choose this mode when you have to capture at high gain, for example, a vary dark object. Please note the switch point of HGC/LGC of QHY600/268/461 is 56. That means you must set Gain 56 to make the best of it.
Extended Fullwell Mode (Mode#2)
With a pixel size of 3.76um, these sensors already have an impressive full well capacity of 51ke. Nevertheless, QHYCCD has implemented a unique approach to achieve a full well capacity higher than 51ke- through innovative user controllable read mode settings. In Extended Fullwell Mode, the QHY600 can achieve an extremely large full-well charge value of nearly 80ke- and the QHY268 can achieve nearly 75ke-. Greater full-well capacity provides greater dynamic range and large variations in magnitude of brightness are less likely to saturate.
2CMS Modes
Extended Fullwell Mode-2CMS (Mode#3)
Photographic DSO Mode-2CMS (Mode#4)
High Gain Mode-2CMS (Mode#5)
Based on the three basic modes above, 2CMS mode can greatly reduce readout noise by secondary sampling while keeping the same full well value and system gain. We prefer 2CMS modes than basic modes in astrophotography. By the way, the recommend gain values are the same as their basic modes.
Specifications
| Model | QHY268M Pro I |
| Image Sensor | Sony IMX571 |
| Sensor Type | Mono Only |
| FSI/BSI | BSI |
| Pixel Size | 3.76μm*3.76μm |
| Effective Pixels | 26 Megapixels |
| Effective Image Area | Typical APS-C |
| Effective Pixel Area | 6252*4176 |
| Total Pixel Area | 6280*4210 (include optical black area and overscan area) |
| A/D | Native 16-bit (0-65535 greyscale) A/D |
| Full Well Capacity (1×1, 2×2, 3×3)
|
Standard Mode
51ke- Extended Full Well Mode >75ke- |
| Read Noise | 1.1e- to 3.5e-
(5.3e- to 7.4e- in Extended Full Well Mode) |
| Dark Current | 0.0005 e-/pixel/sec @-20℃，
0.001 e-/pixel/sec @-10℃ |
| Exposure Time Range | 30μs-3600sec |
| Shutter Type | Electronic Rolling Shutter |
| Computer Interface | USB3.0
2*10Gigabit Fiber |
| Filter Wheel Interface
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4PIN QHYCCD CFW Port |
| Trigger Port | Programmable TrigOut, High Speed Sync Port / GPS interface Port |
| Full Frame Rates | USB3.0:
6.7FPS@8bit 6.5FPS@16bit
12bit High Speed Mode: 14.5FPS@8bit 6.5FPS@16bit
PCIE Mode: 6.7FPS@8bit 6.7FPS@16bit |
| ROI Frame Rates
|
USB3.0:
2048lines,13.6FPS@8bit, 12.7FPS@16bit 1080lines, 25.4FPS@8bit, 21.8FPS@16bit 768lines, 35.5FPS@8bit, 28.3FPS@16bit 480lines, 52.9FPS@8bit, 39.6FPS@16bit
12bit High Speed Mode: 2048lines, 29.1FPS@8bit, 12.7FPS@16bit 1080lines, 52.5FPS@8bit, 21.8FPS@16bit 768lines, 73.2FPS@8bit, 28.3FPS@16bit 480lines, 110FPS@8bit, 39.6FPS@16bit
PCIE Mode: 2048lines, 14.0FPS@8bit 14.0FPS@16bit 1080lines, 25.4FPS@8bit 25.4FPS@16bit 768lines, 35.5FPS@8bit, 34.6FPS@16bit 480lines, 52.9FPS@8bit, 52.9FPS@16bit |
| Built-in Image Buffer | 2GB DDR3 Memory Buffer |
| Air Cooling System | Dual Stage TEC cooler:
– Long exposures (> 1 second) Typically -35℃ below ambient – Short exposure (< 1second) high FPS, Typically -30℃ below ambient（Test temperature +20℃） |
| Liquid Cooling | Available Only in LQ Version.
-45℃ below ambient with water cooling; more deltaT below ambient with cold liquid. |
| Recommended Flow Rates | 1.6ml/s |
| Anti-Dew Heater | Available |
| Humidity Sensor | Available |
| Firmware/FPGA remote Upgrade | Available via Camera USB port |
| Optic Window Type | AR+AR High Quality Multi-Layer Anti-Reflection Coating |
| Back Focal Length | 14.5mm |
| Adapters | Support 2-inch, M54, M48, Nikon/Canon DSLR Lens, etc. (Combined with adapters) |
| Weight | About 1kg |
| Power | 40W/100%
20W/50% 13.8W/0% |
Mechanical Drawing
User Guide
Install “All-In-One” Driver&SDK Pack
Before Start: Input Voltage Requirements
The camera requires an input voltage between 11V and 13.8V. If the input voltage is too low the camera will stop functioning or it may reboot when the TEC power percent is high, causing a drain on the power. Therefore, please make sure the input voltage arrived to the camera is adequate. 12V is the best but please note that a 12V cable that is very long or a cable with small conductor wire may exhibit enough resistance to cause a voltage drop between the power supply and the camera. The formular is: V(drop) = I * R (cable). It is advised that a very long 12V power cable not be used. It is better to place the 12V AC adapter closer to the camera.
First connect the 12V power supply, then connect the camera to your computer via the USB3.0 cable. Make sure the camera is plugged in before connecting the camera to the computer, otherwise the camera will not be recognized. When you connect the camera for the first time, the system discovers the new device and looks for drivers for it. You can skip the online search step by clicking “Skip obtaining the driver software from Windows Update” and the computer will automatically find the driver locally and install it. If we take the 5IIISeries driver as an example (shown below), after the driver software is successfully installed, you will see QHY5IIISeries_IO in the device manager.
Please note that the input voltage cannot be lower than 11.5v, otherwise the device will be unable to work normally.
Install "All-In-One" System Pack
All-in-one Pack supports most QHYCCD models only except PoleMaster and several discontinued CCD cameras.
Download Page: https://www.qhyccd.com/download/
Video Tutorial: https://www.youtube.com/embed/mZDxIK0GZRc?start=1
- Since most of the contents of All-in-one package are plug-ins that support third-party software, the third-party capturing software that you want to use must be installed before the All-in-one package. Otherwise the program will report an error.
- ALL-IN-ONE Pack contains:
- System Driver, which is necessary for the camera operation and must be installed.
- WDM Broadcast Driver, which can provide a live signal to Obs and other live software, you can install it if you have such needs like opeing a live show.
- EZCAP_QT , which is developed by QHYCCD and can be used in QHY devices tests, and management of updates. So even if you won’t use EZCAP_QT for capturing, we suggest you install it.
- Ascom driver, which is necessary for the camera used in Ascom (the latest version of Ascom is 6.6).
- The two sorts of Ascom CFW Drivers correspond to two methods of controling the filter wheel: USB control and camera serial control. It is recommended that both drivers should be installed if you have a filter wheel.
- CP210X_VCP is a serial driver. Some computers come with the driver, but the computer without the driver may be failed of controling the filter wheel.
- SDKs for Third-party Software: Just pick and install the corresponding SDK according to the software you want to use. Don’t forget to check whether the software you are using is 32-bit or 64-bit and select the right SDKs.
- SHARPCAP is also included in the pack, you can choose 32-bit or 64-bit to install. This is authorized by SHARPCAP.
- QT LIB is a plug-in to ensure that 64-bit software can exeuate normally on some computers with poor compatibility.
- Difference between Stable version and Beta Version: Beta version is the latest version, which gives priority to support for the latest products (the stable version may not be compatible with those yet), and has some of the latest optimized ,but experimental features. The stable version is older than the beta version but more stable, so it is recommended for beginners who are not using the latest products.
- Don’t let the camera connect to the computer during the All-in-one pack installation process; connect it to the computer after all the installation is complete.
Connect DSO Imaging Software (e.g. NINA)
Before using software, make sure you have connected the cooling camera to the 12V power supply and connected it to the computer with a USB3.0 data cable. If it’s an uncooled camera, 12V power is not needed. We recommend 64-bit Software, like SharpCAP x64 , N.I.N.A x64. etc., especially when you’re using 16bit cameras.
In NINA, you can select the device to connect to QHY Camera directly without ASCOM driver.
If connecting to the camera via ASCOM is desired, first make sure you have installed both the QHYCCD ASCOM Drivers and ASCOM Platform. Then you would select the appropriate camera driver under the ASCOM section. Then click the Connect icon. Here we take NINA as an example, but it’s similar to other software packages supporting ASCOM, like MaxDL, The SkyX, etc.
Connect Planetary Imaging Software (e.g. SharpCap)
Launch SharpCap. If the software and drivers mentioned above are installed successfully, the video image will appear automatically about 3 seconds after the software loads. You will also see the frame rate in the lower left corner of the software window as shown below.
If you have already started the SharpCap software before connecting the camera, in order to open the camera, click on the “camera” in the menu bar and then select the device.
Offset adjustment. When you completely block the camera (i.e., like taking a dark frame) you may find that the image is not really zero. Sometimes this will reduce the quality of the image contrast. You can get a better dark field by adjusting the offset. You can confirm this by opening the histogram as indicated in the figure below.
If you want to enter the 16-bit image mode, select the “RAW16” mode.
By selecting the “LX” mode you can expand the exposure setting range and take long exposures.
After cooling devices connected to the 12V power supply, the temperature control circuit will be activated. You can control the CMOS temperature by adjusting the settings in the figure below. Basically, you can control the temperature of CMOS by either adjusting “Cooler Power” or clicking “Auto” and setting “Target Temperature”. You can also see the CMOS temperature at the lower-left corner of the software window.
Advanced Control Tools
Click to download （2021.1.2）
Run Sharpcap and make sure the QHY Camera works well under it. You will see the continous image appears.
Click “connect” button and it will show camera name and series number.
select QHY Camera tabl.
check on the “Enable TrigOut” Input 2 to the textbox near to the “GPIO PORT MODE”. Then click the “GPIO PORT MODE” Button to set the GPIO working mode.
Check the waveform output from the TrigPort.
The introduction of different GPIO PORT MODE
MODE0: Generic GPIO output mode / Auto Guide Port
In this mode. Four GPIO port is all output . You can control each port to output high or output low with the API. This mode does not controlled by Enable TrigOut.
You can select the check box of MODE0, GPIO1,GPIO2,GPIO3,GPIO4 to test this mode. This mode is also been used to test if the socket io port working well.
MODE1: 6PIN QHY-GPSBOX mode
In this mode, Four GPIO port is configed as gps_clock, gps_data, shuttermeassure,gps_control. You can connect with QHYCCD-GPSBOX. The camera will output the shuttermeassure signal to GPSBOX and GPSBOX will send the data to camera. Camera will replace the first some pixel to the gps data .
MODE2: 5PIN Generic TrigOut / TrigIn mode
In this mode, Four GPIO port is configed as TrigOut, ShutterMeassure, TrigIn, LinePeriod . Only TrigIn pin is input direction and other three pin is output direction.
In some camera, like QHY4040,QHY2020,QHY42PRO,QHY6060, The shuttermeassure waveform rising edge is the start exposure time and falling edge is the end exposure time 。 in other camera like QHY600,QHY268, QHY411,QHY461 etc, The shuttermeassure waveform is the vsync signal . It is near to the end of exposure time of the first row. For more information of TrigOut,LinePeriod. Please see some other document of QHYCCD supplied.
MODE3: 4PIN GPS Card TrigIn mode
In this mode. there is two pin is configured as ouptut . Both of the two pins is the shuttermeassure signal but one of it is inverted. This is suitbale for some GPS card which need such a “differencial signal”. But please note this is not LVDS signal. It is still TTL signa,
MODE4: Multi-Camera Master Mode
TO BE ADDED
MODE5: Multi-Camera Slave Mode
TO BE ADDED
MODE6: LED Calibration Mode
By using the controlled LED pulse, we can calibrate the distance from the TrigOut or ShutterMeassure signal to the real pixel/row start/end exposure time. To use this mode. You need to connect a LED to one GPIO pin and let the camera capture the flash that output from the camera. The start time and end time relative with the TrigOut/ShutterMeassure can be set by APIs. By check if the camera captured this pulse. You will get the delta time of the TrigOut/ShutterMeassure signal and use it to calibrate the messured GPS time.
| mode 0 | mode 1 | mode 2 | mode 3 | mode 4 | mode5 | mode6 |
| GPIO1 | GPSBOX_Control | ShutterMessure+ | ShutterMessure+ | n.a | n.a | ShutterMessure+ |
| GPIO2 | GPSBOX_Data (IN） | TrigIn2 | ShutterMessure- | n.a | n.a | TrigIn2 |
| GPIO3 | GPSBOX_ShutterMessure | LinePeriod | n.a | HSYNC(OUT） | HSYNC（IN) | LinePeriod |
| GPIO4 | GPSBOX_CLK | TrigOut | n.a | VSYNC(OUT） | VSYNC(IN) | LED(OUTPUT) |
| GND | GND | GND | GND | GND | GND | GND |
UVLO Function
UVLO（Under Voltage Locking), is primarily intended to protect the electronic device from damage caused by abnormally low voltages. Now only QHY600, QHY268, QHY410, QHY411, QHY461, QHY533 cameras have UVLO Protection.
UVLO warning execution
After a warning is given, the camera firmware will automatically turn off the cooler and will turn on the camera’s TEC protection mode. After the camera is reconnected, it will always work in TEC protection mode (maximum power cooler power will be limited to 70%). Since many times the voltage shortage is caused by the high resistance of the power supply cable itself, resulting in a large voltage drop at high currents, the voltage will usually rise after the power is limited. But limiting the power will affect the cooling temperature difference. Therefore, it is recommended that users first check the power supply cable to solve the problem of excessive resistance of the power supply cable.
If the user has solved the problem of insufficient supply voltage, the TEC protection mode can be removed through the menu of EZCAP_QT.
How to improve the power supply?
- Make sure the output voltage of the AC adapter is not less than 12V and the maximum output current can reach 4A or more. Otherwise, the AC adapter itself will not meet the power demand of the camera and it may cause a low voltage problem.
- Make sure that the 12V power supply cable connecting the AC adapter to the camera has a low impedance. The impedance of the positive and negative paths should not exceed 0.1 ohms each. Or the total impedance (positive + negative) should not exceed 0.2 ohms. Otherwise, the power supply cable should be thickened.
- When using battery power, it is recommended to add a 12V output voltage regulator. If the battery is connected directly, usually the battery voltage reaches 13.8V when fully charged, and will gradually drop during use. It is easy to cause the camera to reach the low-voltage detection threshold.
How to clear the TEC protection status triggered by UVLO?
Once a UVLO event occurs, the camera will automatically memorize it and will work in a protected mode at a maximum of 70% power after reconnection. This memory can be erased as follows:
After you find the system error, you need to turn off the device and check the power supply. After inspecting the problem, open the ezcap software and select “Camera Settings” – “Preferences” – “Reset Flash Code” to reset the error status.
Why does the warning appear even though the power supply voltage is 12 V?
- The voltage measured inside the camera is the voltage reaching the camera, not the voltage at the power adapter end. Therefore, the voltage measured at the power adapter end does not reflect the voltage received at the camera end. This is because the power cable has its own resistance. If the resistance is large, it will cause a large voltage drop. The voltage drop can be calculated by U = I * R. So if the power cable has a resistance of 0.2 ohms, it will produce a voltage drop of 3.3 * 0.2 = 0.66V. If the power adapter output is 12 V, the voltage reaching the camera is 12 – 0.66 = 11.34 V. To actually measure the input voltage at the camera end, you can refer to the photo below.
- For cameras produced after September 2021, the UVLO is detected by communicating directly with the power manager, and the UVLO code that appears is 9, while for cameras produced before, the indirect detection method is used, and the UVLO code that appears is 3. The indirect detection method will detect UVLO except for the low voltage problem, and any other accident that causes CMOS not to work will also trigger the UVLO=3 alarm, for example, the camera is subject to severe electromagnetic interference, causing registers inside the CMOS not to work. Therefore, if UVLO=3 occurs, it is recommended to contact QHYCCD technical support for further judgment.
- Using older versions of drivers and firmware may cause false positives (UVLO=9). Please make sure that ALL-in-one SDK version is out of stable version 2021.10.23 or higher. Please disconnect the 12V power supply during the driver installation.
QHYCCD BURST Mode
QHYCCD BURST Mode
Added functions related to BURST mode in SDK. Currently, cameras that support Burst function include QHY600, QHY411, QHY461, QHY268, QHY6060, QHY4040, QHY4040PRO, QHY2020, QHY42PRO, QHY183A
This mode is a sub-mode of continuous mode. This function can only be used in continuous mode. When this function is enabled, the camera will stop outputting image data, and the software frame rate will be reduced to 0. At this time, send relevant commands to the camera, and the camera will Output the image data with the specified frame number according to the settings, for example, set Start End to 1 6, the camera will output the image data with the frame number 2 3 4 5 when receiving the command.
Note:
1. When using Burst mode in fiber mode, the first Burst shot will be one less. For example, if the start end is set to 1 6, the output of 2 3 4 5 is normal, but in fact, only 3 4 will be output during the first burst shot. 5, 2 will not be received, the second and subsequent shots can normally obtain Burst images 2 3 4 5. This problem will be fixed later.
2. QHY2020, QHY4040 found that the frame number that came out when the exposure time was short is [start+1,end-1] but the one that came out under long exposure was [start+2,end]
3. When the camera is just connected, if the set end value is relatively large, the camera will directly output the picture after entering the burst mode. Therefore, it is necessary to set the camera to enter the IDLE state and then set the start end and related burst operations.
The following is the usage of Burst mode related functions:
1.EnableQHYCCDBurstMode
2.SetQHYCCDBurstModeStartEnd
3.SetQHYCCDBurstIDLE
4.ReleaseQHYCCDBurstIDLE
5.SetQHYCCDBurstModePatchNumber
6.ReseQHYCCDtFrameCounter
7.SetQHYCCDEnableLiveModeAntiRBI
8.EnableQHYCCDImageOSD
Sample Code
Maintenance
Drying the camera CMOS chamber
- There are holes in the two sides of the camera near the front plate that is normally plugged by a screw with an o-ring. If there’s moisture in the CMOS chamber that causes fog, you can connect the desiccant tube to this hole for drying. There would better be some cotton inside to prevent the desiccants from entering the CMOS chamber.Please note that you may need to prepare desiccants yourself, because for most countries and regions desiccants are prohibited by air transport. Since QHY always deliver your goods by air, sorry that we can’t provide desiccants for you directly.
- Cyclic Drying: The front end of the camera body is equipped with two drying interfaces with M5 threads, which are used in conjunction with drying tubes and circulation pumps for drying treatment inside the sensor chamber. The position of the drying interface is indicated by the red circle in the figure below (take the QHY600 as an example):Under the vacuum pump, the gas inside the sensor chamber is drawn out through one drying interface, enters the drying tube, and then undergoes filtration. It is then reintroduced into the camera through the other drying interface, circulating back and forth for drying.
Note:1.Do not reverse the order of the intake and exhaust ports
2.Before circulating drying, it is necessary to turn off the refrigerator, and then turn on circulating drying after the temperature returns to normal temperature. Only by following this step can the water vapor in the sealed chamber be effectively removed. If the cooler is turned on, the cooler inside the camera will absorb water vapor, causing more water vapor to condense inside the camera instead of being absorbed by the desiccant.
Cleaning the CMOS sensor and optical window
If you find dust on the CMOS sensor, you can first unscrew the front plate of the cam and then clean the CMOS sensor with a cleaning kit for SLR camera sensors. Because the CMOS sensor has an AR (or AR/IR) coating, you need to be careful when cleaning. This coating can scratch easily so you should not use excessive force when cleaning dust from its surface.
Preventing fogging of the CMOS chamber
All QHY cooling cameras have built-in heating plates to prevent fogging. However, If the ambient humidity is very high, the optical window of the CMOS chamber may have condensation issues. Then try the following:
1. Avoid directing the camera towards the ground. The density of cold air is greater than of hot air. If the camera is facing down, cold air will be more accessible to the glass, causing it to cool down and fog.
2. Slightly increase the temperature of the CMOS sensor .
3. Check if the heating plate is normally working. If the heating plate is not working, the glass will be very easy to fog, the temperature of the heating plate can reach 65-70 °C in the environment of 25 °C. If it does not reach this, the heating plate may be damaged. Please contact us for maintenance.
TE Cooler Maintenance
Please avoid thermal shock during use. Thermal shock refers to the internal stress that the TE cooler has to withstand due to the thermal expansion and contraction when the temperature of the TEC suddenly rises or falls. Thermal shock may shorten the life of the TEC or even damage it.
Therefore, when you start using the TEC to adjust the CMOS temperature, you should gradually increase the TEC power rather than turning the TEC to maximum power. If the power of the TEC is high before disconnecting the power supply, you should also gradually reduce the power of the TEC and then disconnect the power supply.
Appendix: Test for QHY268M for Science Observations by Alto-observatory
https://www.qhyccd.com/testing-the-qhy-268-mono-for-science-observations/
