DISCOVER NEW HORIZONS
Telescope: Planewave CDK 14 with Televue 0.8x reducer
Exposure: L:R:G:B 60:32:30:30 x 600 s
Hα:OIII 123:118 x 600 s
Location: Gemsbock Observatory, Rooisand Desert Ranch, Namibia
One benefit of the back-illuminated CMOS structure is improved sensitivity. 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.
Unlike Most CMOS cameras, the camera supports charge-domain binning (FD Binning), which is the true hardware pixel binning similar to CCD cameras.
In the past, only CCD sensors were capable of hardware binning. Most CMOS cameras used digital binning, which relied on algorithms for binning. 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 then frame rate can not be improved. In contrast, hardware binning does not amplify additional noise, resulting in a direct 4-fold improvement in the signal-to-noise ratio. What’s more, the frame rate can increase a lot even the ROI function is not activited.
| Model | QHY811 Pro |
| Image Sensor | Sony IMX811 |
| Sensor Type | Both Available |
| FSI/BSI | BSI |
| Pixel Size | 2.81 μm * 2.81 μm |
| Sensor Size | Typical 4.1-inch |
| Effective Pixels | 245 Megapixels |
| Effective Pixel Area | 19240*12840 |
| Total Pixel | 19776*13120 (include optical black area and overscan area) |
| A/D | Native 16-bit (0-65535 greyscale) A/D |
| Full Well Capacity | 28ke- |
| Read Noise | 1.2e- to 3.2e- |
| Dark Current | Apporx 0.00053e-/pixel/sec @ -30℃ |
| Exposure Time Range | 20 μs – 3600 sec |
| Shutter Type | Electronic Rolling Shutter |
| Computer Interface | USB 3.0
2*10 Gigabit Fiber |
| Filter Wheel Interface | 4-PIN QHYCCD CFW Port |
| Trigger Port | Programmable TrigOut, High Speed Sync Port / GPS interface Port |
| Full Frame Rates | USB3.0:
Normal Mode 1.5FPS@8bit 0.6FPS@16bit 2×2 FD Binning 5.6FPS@8bit 2.9FPS@16bit
PCIE Mode: Normal Mode 2FPS@8bit 1.5FPS@16bit 2×2 FD Binning 8.1FPS@8bit 5.7FPS@16bit |
| ROI Frame Rates
|
USB3.0:
Normal Mode 8000lines, 2.4FPS@8bit, 1.3FPS@16bit 6000lines, 3.3FPS@8bit, 1.6FPS@16bit 2000lines, 8.9FPS@8bit, 4.6FPS@16bit 2×2 FD Binning 4000lines, 9FPS@8bit, 4.5FPS@16bit 2000lines, 17.8FPS@8bit, 8.9FPS@16bit 1000lines, 33.6FPS@8bit, 16.8FPS@16bit
PCIE Mode: Normal Mode 8000lines,3.1FPS@8bit, 2.4FPS@16bit 6000lines, 4FPS@8bit, 3.1FPS@16bit 2000lines, 11.3FPS@8bit, 8.6FPS@16bit 2×2 FD Binning 4000lines, 13.3FPS@8bit, 9.6FPS@16bit 2000lines, 25.9FPS@8bit, 18.8FPS@16bit 1000lines, 48.4FPS@8bit, 35.7FPS@16bit |
| Built-in Image Buffer | 2GB DDR3 Memory Buffer |
| Air Cooling System | Dual Stage TEC cooler |
| Liquid Cooling | Available |
| Recommended Flow Rates | 12 ml/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 |
| Adapters | Customization |
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.
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
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.
NINA supports direct connection via the QHY plugin as well as connection through the ASCOM driver. The following instructions assume a direct connection using the QHY plugin.
Set the Target temperature.
Set exposure time and start the shooting.
The instructions below are based on SharpCap 3.1
Click Camera in the menu bar and select your camera.
If the software and drivers mentioned above have been installed correctly, the image will appear automatically. And the frame rate can also be seen in the lower-left corner of the software window, as shown below.
Capture Profiles
Preset management.
After SharpCap is restarted, the default settings are restored. If you frequently use one or more specific parameter configurations, you can adjust the parameters as needed and then click Save to store them as a preset. The preset can be directly recalled the next time you open the software.
Exposure
Sets the exposure duration. When LX Mode is enabled, the single-frame exposure time can be extended to longer values.
Gain
Equivalent to the ISO setting on a standard digital camera. Higher gain values result in higher sensitivity.
Frame Rate Limit
Limits the maximum frame rate. By default, no limit is applied. Users can set the limit manually if needed.
Offset
Adjusts the bias level. Even when the camera is completely covered, the image may not appear perfectly black. By adjusting the offset value, a more optimal dark frame can be achieved. The Histogram can be used to verify the adjustment.
USB Traffic
Controls the data transfer speed (frame rate). When set to 0, the camera operates at its maximum frame rate.
Enable Broadcast Mode
Enables the broadcast driver. For detailed usage instructions, please refer to the documentation available on the download page.
Read Mode
Some camera models support high-gain and low-gain readout modes.
Color Space
Select the output format.
Raw8 / Raw16 are 8-bit or 16-bit formats. Images and videos saved in Raw8 or Raw16 format will be monochrome, even when using a color sensor. Color information must be restored through debayering during post-processing.
RGB24 is a non-RAW format that outputs color images directly, but requires more storage space.
Capture Area
Select the resolution used for image capture.
Binning
Enable pixel binning for image capture.
Output Format
Select the output file format.
Debayer Preview
When this function is enabled, the live preview will be displayed in color even if a RAW format is selected. Please note that the saved images will still be monochrome.
Gamma, Brightness, Contrast
Under normal operating conditions, we recommend leaving these settings unchanged.
White Balance (R/G/B)
This function is used for white balance calibration on color cameras. For detailed calibration instructions, please refer to the corresponding section on the color camera page.
This function is not required for monochrome cameras.
Histogram
The histogram is an important image reference tool. It can be used to check whether the white balance is set correctly, whether the offset value is appropriate, and whether the image is overexposed.
Its operating principle is the same as that of the histogram used in standard DSLR cameras.
Thermal Controls
After the cooled camera is connected to a 12 V power supply, the temperature control circuit will be activated. You can control the CMOS sensor temperature by adjusting the settings shown below.
There are two main methods for temperature control:
Adjusting the cooler power
Setting a target temperature
If you wish to control the CMOS temperature by setting a target temperature, first click “Auto”, and then use the slider to set the desired target temperature.
Scope Control: for filter wheel control
Select the corresponding filter wheel slot to control the rotation.
Note: The software must be started after the filter wheel has completed its rotation and returned to the home position; otherwise, the position will not be displayed correctly.
QHY devices can operate with many software applications that support the ASCOM platform. MAXIM DL is used as an example below.
First, make sure that both the ASCOM platform and the QHY ASCOM driver have been successfully installed. Launch MAXIM DL and follow the instructions shown in the figure below to complete the setup.
Click “Connect”
Set the cooling temperature.
EZCAP_QT is software developed by QHYCCD. For QHYCCD cameras, it provides basic image capture functions.
Install the EZCAP_QT software and connect the camera to your computer using a USB 3.0 cable. Launch EZCAP_QT, then click “Connect” under Menu → Camera.
If the camera is successfully connected, the EZCAP_QT title bar will display the camera firmware version and camera ID, as shown in the figure below.
In Camera Setup, click Temp Control to set the CMOS sensor temperature.
You can enable Auto to define a target temperature. For example, here we set the target temperature to –10 °C. The CMOS sensor temperature will quickly drop to the target value, typically within 2–3 minutes.
To disable cooling, select Stop. If you prefer to control the cooling power without setting a target temperature, you can manually set the cooling power as a percentage.
In EZCAP_QT, there is an Image Task Planner for sequence imaging.
Check Use to enable the task.
Set the following parameters:
Bin
ExpTime – exposure time
Repeat – number of frames
CFW – filter wheel position
Gain – gain value for the sequence
Click Folder to set the save path. (It is recommended to avoid special characters in the path and use English letters.)
Click Start to begin the sequence capture, and Force Stop to close the current task.
Since QHY411 is usually connected to a large telescope, especially the prime focus of a large telescope, it is not convenient to disassemble it at this time. Therefore, QHY411 is designed with a built-in drying system to facilitate maintenance work and solve the problem of maintenance-free long-term use.
QHY411 has a built-in CMOS sealed chamber humidity sensor and a built-in circulation pump. The real-time humidity value of the sealed chamber can be read through the API. When the humidity is high, the maintenance personnel should start the camera’s built-in circulation pump to dehumidify the air in the sealed chamber. Since the sensor and pump are both built-in to the camera and controlled by the QHYCCD API, this design is very suitable for remote operation.
EZCAP-QT can realize the functions of real-time humidity reading and control of the circulating drying pump as shown in the figure. (Note: Use EZCAP_QT software to turn off camera cooling (TEC OFF) and observe the humidity display curve (RH) of EZCAP_QT. The cyclic dehumidification function in the software was added on 2020-11-27. Please use the version on 20-11-27 or later.)
Start the camera’s built-in air circulation pump (click SensorChamberCyclePUMP)
The display value of the humidity display curve decreases. After about 5 minutes, the software automatically turns off the air circulation pump and completes the camera drying process (If the humidity curve is still not ideal, please restart the air circulation pump in the software.)
If you need secondary development, please refer to:
Instructions for the switch pump API function:
If the ambient humidity is very high, the optical window of the CMOS sealed cavity may have condensation problems. QHY411 has a built-in heating plate to heat the lens to prevent fogging. In most cases, it works very well. If the fogging problem still exists, please try the following methods:
1. Avoid pointing the camera to the ground. The density of cold air is greater than that of hot air. If the camera is facing downward, cold air will more easily contact the glass, causing it to cool down and fog up.
2. Increase the temperature of the CMOS sensor. You can slightly increase the temperature of the CMOS sensor to prevent the glass from fogging.
3. Check whether the heating plate is working. If the heating plate is not working, the glass will fog up very easily. Normally, the temperature of the heating plate can reach 65-70℃ in an environment of 25℃. If it does not reach that hot, it may be because the heating plate is damaged. You can contact us to replace the heating plate.
The cylindrical protrusion at the rear of the QHY411/461 camera is where the desiccant is stored. After long-term use, the internal desiccant will become ineffective and needs to be replaced to keep it dry. The replacement steps are as follows:
1. Open the 4 screws on the top of the drying cylinder.
2
3. Remove the cover of the drying cylinder and replace the desiccant inside. (Blue desiccant turns pink after it expires. Orange desiccant turns green after it expires. Please pay attention to the color of the desiccant to determine whether the desiccant is effective.)
4. Seal the dryer cover.
