QHYCCD COLDMOS QHY163M, Руководство пользователя

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QHY163M
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5. How to clean the CMOS sensor and the optic windows of the camera?
If you found there is dust on the CMOS sensor. You can screw off the front part of the QHY163M. The
QHY163M’s CMOS sensor has the AR coating so you need to be careful to clean it. You can use the
clean kit for DSLR sensor to do it.
The optic window is the IR cut coating or AR coating. So you need to be careful when cleaning it. You
can also use the DSLR clean tools or the lens paper.
Don’t use strong force to clean it. The coating
is not so hard and it is easy to get scratch when you use strong force on it.
6. How is the anti-amplifier function in QHY163M?
QHY163M camera has the anti-amp light control circuit and it can reduce the amplifier glow
significantly. Note that it’s impossible to reduce the glow in the corner thoroughly, and it’s normal to
see a very small amount of glow in the corner when you do long exposure.
This is a demo picture for the QHY163M glow in 60sec exposure and high gain. Dark frame
calibration can remove it completely.
7. How to eliminate the bad effects of the amplifier glow?
When the exposure time is very long, amplifier glow in the corner will become more obvious. This is
normal, and there is no need to worry because you can use dark frame calibration to eliminate its bad
effects totally. Before or after you take a normal frame, you should take a dark frame with the same
setting (exposure time, gain, temperature, etc.). Then open these two images by using MaxIm DL
and subtract dark frame from the normal frame with its Pixel Math function as shown below, then the
bad effects of amplifier glow will be eliminated. Note that, when doing subtraction, you should add a
constant to prevent pixel value from being subtracted to negative value and becoming zero. The
constant should not be too big, otherwise, its RMS will be too big; It should not be too small either,
otherwise, the pixel value will be subtracted to negative value and becomes zero, too. The value of
the constant can be determined with the assistance of Histogram and should guarantee that the pixel
value are in the effective range, which is from 0 to 65535.