QHY174GPS

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.

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.

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.

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.

1. 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.
2. 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.

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.

Mode 1：Hardware External Trigger. The exposure time is depent on the external pulse width

In the Trig Input Souce trigger input source drop-down selection, select Trig Input Pin Direct. The meaning is to trigger the input source as the external trigger input port of the camera (opto-coupled isolated, RCA gold plug); Select one in Trig Controller Source (the marquee doesn’t make sense for this mode, so choose one)

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.

Press the diagram to set it up. Choose XTRIG CONTROLLER in Trig Input Source, Trig Input Phase to Rise Edge, Trig Controller Controller Enable Source select Trig Controller by Hardware. And enter exposure time, such as 50ms. Then click the TRIG MODE ON button to complete the setting of the mode and the exposure time setting.

Mode 3： Out-of-software trigger, exposure time is determined by the software command interval

In this mode, the software sends a start exposure instruction through the software, and then the software waits for a delay. Then send an end exposure instruction. A trigger for software control is possible. Its exposure time is equal to the time between the start and end exposure commands. Just follow the settings below. Once set up, click TRIG MODE ON to feed the instruction. Then click on the Software Register Trig Test button to observe the shooting. To modify the exposure time, you only need to modify the value sits in the exposure time box, instead of clicking TRIG MODE ON, just click the RegisterSoftware Trig Test button.

Mode 4：Out-of-software trigger, exposure time set by the software

In Mode 3, there is a problem with a less stable and accurate exposure time. The reason is that the time interval between the two instructions sent by the upper computer is not so precise and will be affected by CPU delay, busyness and other factors. Therefore, mode 4 is also provided. Set the pattern as shown below.

Mode 5: Out-of-hardware trigger, sequence shooting

In this mode, continuous shooting can be achieved by means of external triggering. The camera is waiting until a trigger signal is given, and once a trigger signal is given, the camera starts shooting continuously. Exposure time is set by the software.

Follow the figure below to set it up. Once set up, press the TRIG MODE ON button to keep the camera waiting, and then enter a high-level pulse from the optically isolated trigger input to trigger continuous shooting by triggering continuous shooting by the camera. (It is important to note that QHY174 does not work when the exposure time is short, and the exposure time is longer.) If you want to enter the next wait state, click TRIG MODE ON to restore the camera to the waitstate and wait for the next external trigger pulse to arrive.

Mode 6: Out-of-software trigger, sequence shooting

Similar to Mode 5, the trigger source is entered from external hardware to software control. After pressing the diagram to set up, click TRIG MODE ON, the camera waits, at this time click on the Software Register Trig Test button, after the start signal, you can see the start of continuous shooting.

Additional instructions:

The SHARCAP software has a random horizontal horizontal stripe noise reduction feature in the right menu bar. CMOS of the global shutter, such as 174, horizontal random horizontal stripes are more obvious at high gain, and this column can be adjusted appropriately. Comparing the image below, there is no on and off effect, and the difference can be seen.