TO EXPLORE THE UNKNOWN UNIVERSE
NGC 6888 and bubble soap nebula
APOD 2023 Sep 04
Imaging Camera QHY268M
Integration 44 hours 30 min
Telescope: Askar FRA600
Mount: iOptron CEM40
|COMS Sensor||SONY IMX174 CMOS|
|Effective Pixel Area||1920*1200|
|Effective Image Area||11.25mm*7.03mm|
*Please contact QHYCCD about the price.
“This effort, spanning six months, three spacecraft, 24 portable ground-based telescopes, and NASA’s SOFIA airborne observatory was the most challenging stellar occultation in the history of astronomy, but we did it!” said Alan Stern, New Horizons principal investigator from SwRI.
The QHY174GPS camera uses the 1/1.2-inch SONY IMX174 CMOS sensor with global shutter, 5.86um pixels,138FPS@1920*1200, high QE of 78%, and low read noise of 3-5e-. It is useful for imaging occultations, eclipses, meteors, and other scientific imaging requiring a highly precise recording of the time and location of the observation on every frame.
The QHY174GPS has a unique built-in GPS module that can sync with the atomic clock signals received from GPS satellites. The QHY174GPS can record the start and end of exposure time with 1us precision anywhere on earth. The QHY174GPS was selected by the NASA New Horizons Team to successfully captured the MU69 occultation in the Summer of 2017. The QHY174M-GPS has dual stage TE cooling to -45C below ambient with full anti-moisture control including heated optical window and removable desiccant plug for the sensor chamber. The QHY174 also has an anti-amp glow function. It can reduce the IMX174 sensor’s amplifier glow significantly in long exposures.
The QHY174M-GPS records the global shutter exposure starting and ending time with microsecond precision. Two QHY174 cameras, for example, each located anywhere in the world, can have the same time base, accurate to microseconds. In order to guarantee the starting and ending time of the exposure, the QHY174 has a built-in LED pulse calibration circuit precise to 1 microsecond.
Unlike the rolling shutter technology used in most CMOS cameras, a global shutter guarantees that the exposure time for the whole image area is uniform, beginning and ending at exactly the same time. This type of shutter is ideal for high precision applications. For high speed moving object and the atmospheric agitation the global shutter can generate undisborted imaging and realizes high picture quality.
Master mode: In Master Mode, the camera is free running and the internal 10MHz GPS synced clock will measure and record the shutter’s opening and closing time.
Slave mode: In Slave Mode you can input a target start time and the interval period for two frames. For example: You want three cameras in different locations (maybe thousands of kilometers apart) to start an exposure at 2016.3.9.UTC 14:00:00.000000 and then to continue with exposures at the interval time of 0.100000 sec. After you input these value, all the three cameras will wait until this time and then simultaneously start video recording, e.g.:
2016.3.9 UTC 14:00:00.000033
2016.3.9 UTC 14:00:00.100033
2016.3.9 UTC 14:00:00.200033
2016.3.9 UTC 14:00:00.300033
(The 0.00033 is a global delay of the CMOS shutter).
The time stamp and other GPS information is embedded into the image. The software decodes it in real time and displays the information on left. Since the data is embedded, it will never be lost so long as you keep the original image.
|COMS Sensor||SONY IMX174 CMOS|
|Effective Pixel Area||1920*1200|
|Effective Image Area||11.25mm*7.03mm|
|AD Sample Depth||12/10bit (output as 16bit and 8bit)|
|Sensor Size||Typical 1/1.2 inch|
|Full Frame Rate and ROI Frame Rate||138FPS@1936×1216
*Note：QHYCCD has optimized the cmos drive frequency and limit the max frame rate. The CMOS sensor may not work under the max frequency to ensure the better noise performance. If you need the customized higher frame rate version, please contact QHYCCD.
|ROI Support||Yes. Any Area ROI|
|Readout Noise||5.3e-@Gain0% 2.8e-@Gain60% 1.6e-@Gain100%|
|Exposure Time Range||5us-900sec|
|Anti-Glow Control||Yes (Reduces amplifier glow significantly)|
|Shutter Type||Electric Global Shutter|
|Computer Interface||USB3.0 Super Speed|
|Non-volatile memory / On camera storage||Build-in total 512Kbytes Flash Memory. 100Kbytes user-accessible space for stellar ROI frames for analysis of exoplanet investigation, occultations, atmospheric seeing measurement, focus , optic analysis etc. Support 100*100 image x 10rames 50*50 image x40frames. 25*25 image x160frames 10*10 image * 1000 frames （total frame numbers is based on 8bit image）|
|Cooling System||Dual Stage TEC cooler（-40C below ambient),
(Test temperature +20°)
|Anti-Dew Control||Connector for removable silicon gel tube
Heater board for CMOS chamber optical window
|Telescope Interface||M42/0.75 / 2inch faster installer. Optional C-mount adapter|
|Optic Window Type||Mono Version: AR+AR High Quality Multi-Layer Anti-Reflection Coating
Color Version: IR cut coating
|Guide Port||6PIN RJ11 Guide Port|
|Color Wheel Port||4PIN QHYCFW Socket|
|Back Focal Length||17.5mm|
|GPS version, Time-Stamp Precision||1 micro-second of the GPS UTC clock|
|Reference Price||QHY174M-GPS USD1239 w/TE Cooling|
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.
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.
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.
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.
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.
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.
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.
Press the TRIG MODE ON button. You will find that the video image in sharpCAP software stops. The camera has entered a waiting outside trigger state. Trigger the input port via the photoelectric isolation and enter a high level. You’ll find that the image takes a frame, and the longer the duration of the high level, the longer the image will be exposed. In this mode, the exposure time is equal to the duration of the high level.