07 FAQ
1. How to avoid camera stuck?
If the camera is stuck all the time, it may be caused by a variety of reasons, you can follow the prompts below to check.
1) Whether your computer is configured with a VIA chipset or some type of motherboard, it does not appear on SharpCap (but works on ASCOM). In this case, you need to turn on the camera's DDR buffer.
2) Is your computer and equatorial device leaking? This may cause leakage current to be transferred from the computer to the camera through GND. This may affect USB transmission, loss of data packets, and camera jam. You need to make sure the computer and the equatorial mount are well grounded.
3) Is the voltage of the USB interface high enough? Some computers have a USB interface voltage of less than 5V. This may cause the camera to get stuck. In this case, you can choose to connect the computer to the camera by using the USB3.0 Hub with power supply, which ensures that the camera gets 5V.
4) Is the CPU usage too high? If the CPU usage is too high, it will cause many frames to be lost and the camera will be stuck. You can increase the USB traffic value to lower the FPS for more stable image transmission.
5) Is the USB cable securely connected? Sometimes problems with the connection of the camera to the USB cable and problems with the connection of the computer to the USB cable can result in loss of signal and jamming of the camera. Especially when the USB cable is moving. In this case, you can try applying some silicone oil to the USB connector and the socket section. This will make the USB connection more stable.
6) Avoid static electricity. Sometimes static electricity carried on the human body can cause the camera to become stuck. Before touching the camera, you can touch the computer case to discharge static electricity.
7) Some computers have a front USB interface that is not suitable for high-speed data transmission (because they are connected to the motherboard through a cable, which makes signal integrity worse). If you find that the camera is stuck when the front USB port is in use, you can try connecting the camera to its rear USB port (they are directly connected to the motherboard's chipset).
8) When the USB selective pause function is turned on in the system, it will cause the camera to freeze during long hours of work. Follow the steps below to turn off this option.
Windows power setting steps: 1. Click "Start button" and click "Settings". 2. Click "Power and Sleep", and click "Other Power Settings". 3. Click "Change Power Plan". 4. Click "Change advanced power settings". 5. By default, the "USB Selective Suspend" function is enabled, which will cause the image to freeze, the frame rate is low, the video is not smooth, the image is not refreshed, and so on. We need to disable this feature. 6. Disable this function.
9) When you encounter a situation where the camera cannot output the frame rate after updating the Sharpcap software, please download the AllInOne installation package and check the sharpcap option during installation. The installation package will automatically update the QHY SDK in sharpcap. Restart the sharpcap software after completion.
2. How to clean the CMOS sensor and optical window?
If you find dust on the CMOS sensor, you can first unscrew the front half of the QHY600 and then clean the CMOS sensor with the cleaning kit for the SLR camera sensor. Because the QHY600's CMOS sensor has an AR coating, care must be taken during the cleaning process.
Care must be taken during the cleaning process. You can also use the SLR cleaning tool or lens paper for cleaning. Note that the force should not be too large, because the coating is very fragile and can be easily scratched.
3. What is the camera's built-in DDR buffer? What are its advantages?
The QHY600 has a built-in 1GB（8Gbit）/ 2GB（16Gbit）DDR3 image buffer. It has two advantages:
It can buffer the entire image to avoid loss during USB transmission. Because the CMOS sensor will continue to be exposed as soon as it starts working, the image will be output, and it will not stop. However, the computer will pause the USB transfer because of the multitasking characteristics of the operating system. If the pause time is too long, the buffer with small storage capacity in the USB will be full, resulting in the loss of the upcoming data. It is also possible to cause partial data loss of one frame to form a bad frame. For short exposures, this may not cause too much problems, but for long exposures, this means losing a long exposure image. The 1GB（8Gbit）/ 2GB（16Gbit）DDR3 buffer solves this problem by storing and transmitting the entire frame of images. Even if the USB transfer is paused for a long time, no data will be lost.
Another advantage is that when using some computers that are not running fast or have poor support for USB3.0, it will make the video images more delicate and smooth. These computers can't transfer high-speed data well, and the data will often be lost. With DDR. A buffer that buffers a lot of image data and sends it to the computer. Even if USB 3.0 frequently suspends transmission, it will ensure that data is not lost. There are options in SharpCap to turn DDR buffering on or off. The current version of the ASCOM driver has been working in DDR mode.
4. How to protect the refrigerator?
The QHY600's chiller can achieve an ambient temperature difference of nearly 35 °C. You should avoid thermal shock during use. The so-called thermal shock refers to the internal strong stress that the refrigerator has to withstand due to the thermal expansion and contraction principle when the temperature of the refrigerator suddenly rises or falls. The thermal shock of the distance shortens the life of the refrigerator. Even completely damage the refrigerator.
Therefore, when you start using the chiller to adjust the CMOS temperature, you should avoid turning the chiller to maximum power and gradually increase the chiller power. If the power of the chiller is high before disconnecting the power supply, you should also gradually reduce the power of the chiller and then disconnect the power supply.
5. Horizontal banding Optimize
It is a common behavior for CMOS sensor which contains some horizontal banding. Normally speaking the random horizontal banding can be removed with multiple frame stacking so it will not effect the image. The periodic horizontal banding can not be removed with stacking so it will bring some problem for the image. For QHY600, by adjust the USB traffic in both Single Frame mode or Live Frame mode, you can adjust the frequency point 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 value
After Adjust the USB_Traffic to avoid the periodic horizontal noise
6.
The picture above is a typical situation where part of the image is lost due to USB data transmission errors and causes image misalignment.
The reason is that due to USB communication quality problems or external interference problems, the data of the USB image data packet being transmitted is wrong and cannot pass the CRC check, so the SDK judges it as a USB transmission error. The SDK will repair communication errors to avoid crashes, but this packet of data will also be lost. Cause this phenomenon.
The check and solution are:
(1) Communication quality problems caused by USB cable damage or poor USB contact: The solution is to replace the USB cable, and check the connection of the USB cable to the computer and whether the connection between the USB cable and the camera is too loose.
(2) Some HUBs with mismatched signals may cause such problems. You can connect directly or try to replace other types of HUB. (It is recommended to use active HUB)
(3) The communication interference problem caused by the leakage of the AC adapter, it is necessary to check whether the AC adapter of each device in the system is well grounded.
(4) Use the SDK and firmware that does not match the version, download the latest installation package (QHY recently released the AllInOne installation package, which can automatically replace the SDK with one click, you only need to check the corresponding software in the installation package), or request QHYCCD technology Support remote assistance.
08 Camera Maintenance
Dry camera CMOS cavity
The CMOS sensor is located in the CMOS cavity. There is a hole in the side of the front end of the QHY600 camera. If there is moisture in the CMOS cavity that causes the sensor glass to fog, you can connect the silicone tube through this hole for drying.
Place an effective silica gel desiccant in the silicone rod and make sure there is cotton inside to prevent the silicone from entering the CMOS cavity.
How to prevent fogging of optical window of CMOS sealed cavity
If the ambient humidity is very high, the optical window of the CMOS sealed cavity may have condensation problems. The QHY600 has a built-in heating plate to heat it to prevent fogging. In most cases, its effect is very obvious. If fogging still persists, try the following:
1. Avoid directing the camera towards the ground. The density of cold air is greater than the density 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. Increase the temperature of the CMOS sensor. You can increase the temperature of the CMOS sensor slightly to prevent fogging of the glass.
3. Check if the heating plate is working. If the heating plate is not working, the glass will be very easy to fog. Normally, the temperature of the heating plate can reach 65-70 °C in the environment of 25 °C. If it does not reach this heat, it may be because the heating plate is damaged, you can contact us to replace the heating plate.
