QHY183M & QHY183C

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.

The instructions below are based on SharpCap 3.1

• Launch SharpCap.

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.

• Main Interface Functions:

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.

For beginner, we recommend that you set the gain to “unit-gain”. Unit-gain is the gain when system gain is 1 (1e/ADU). This number is shown in the table above, like the unit-gain of QHY168C is 10. In fact, increasing or decreasing a bit doesn’t make a big difference.

You could increase or decrease Gain according to the condition. For example, if your optical system is fast, like F2.2 to F5, or long exposure for more than 5 minutes without narrowband filters, then you can decrease GAIN to achieve a higher dynamic range and make better use of full well capacity. By doing so you can avoid overexposure.

If you use narrowband filter on a slow optical system like F6 to F10, or short exposure time, the amount of photons received will be less. In this case you can increase GAIN to make better use of characteristics of low read-out noise in high GAIN value.

There is no fixed “best value” for OFFSET. To set OFFSET, you should take the bias frame and dark frame at a certain GAIN value, then check the histogram of the frames.

The histogram distribution is a peak-like curve. While changing the OFFSET value, the histogram will move left or right. We need to guarantee the range of the whole curve won’t be chopped off at the end. At the same time, we need to keep a little residue on the left side, just over 0 a bit.

Pay attention that under different GAIN values, the width of this peak varies. The higher the GAIN is, the wider the distribution will be. So OFFSET value at low GAIN is not suitable for high GAIN because the curve is easily to be chopped off.

For those CMOS less than native 16-bits, the AD sampling accuracy doesn’t match perfectly with the full well capacity. At low GAIN level, the system gain will be couple electrons per ADU. The camera loses the ability to distinguish the strength of the signal because of such sampling error.

When GAIN increases, the system gain will decrease. However, increasing GAIN will limit the full charge of the well. If the system gain is 1 for a 12bit CMOS camera, the pixel will be saturated at only 4096 electrons (full well). Some bright stars will be easily saturated. This problem goes worse under fast optical system or long exposure. Over saturated objects cannot be fixed during post processing (unless you shrink stars, like in PixInsight). Also, the color saturation of the star will be affected. As result, the stars will be huge and white washed. We should decrease the gain value in this case, to gain a higher full well capacity.

Under long exposure or using fast optical system, the pixel will receive more photons. The variation of quantized noise from the photon which you can consider as natural dithering of the light intensity, will be greater than the “noise” from the sampling error. Therefore, the effect of the sampling error will diminish. By averaging multiple exposures, this will compensate the lack of depth of the picture because of the sampling error.

If the number of received photons is limited, like using narrowband filters or short exposures, we can increase the GAIN value. It is because the stars will not be easily saturated. At the same time, we limit the noise from the background cosmic radiation. Under this condition, the readout noise and quantized noise are the major factors that affect the ability to distinguish dim light or objects. By increasing the GAIN value in order to decrease the readout noise and quantized noise from sampling error, this would greatly increase the signal to noise ratio.

But for DSO capture, You should keep the offset above zero and avoid the background is cut off. A background from 1000-5000 is a good value(16bit mode) for DSO imaging.