QHYCCD QHY90A, Руководство пользователя

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QHY90A
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5. How to protect the cooler in QHY90A?
The cooler in QHY90A can lower the CCD temperature to a value that's almost 40 degrees centigrade below
the ambient temperature. So you need to be careful to avoid thermal shock, which refers to when the cooler's
temperature rises or fall dramatically, the cooler is subjected to strong internal stress due to contraction
principle. Drastic thermal shock can shorten cooler's service life or permanently break it.
So when you begin to adjust the CCD temperature, you should avoid setting "Cooler Power" to its maximum
value, and you should gradually turn up the "Cooler Power" value. When you turn off the power, if the
"Cooler Power" value is very big, you should gradually turn it down before turn off the power.
6. What's small display on the camera for?
The OLED display is used for display certain formation related to the shooting. It is directly driven by
application program. So it may display different information or doesn't display anything at all based on
different application programs. Currently all application program don't support this display, please wait for
latest application program that supports this display.
7. What is defect columns?
You may see one or more vertical columns whose top pixel is a bright dot. Normally speaking such columns
are not defect column. It is resulted from one pixel with high thermal current. All the pixels below that pixel
will be affected by it as thermal current is transferred through that pixel.
This pixel can be removed by dark frame calibration. If they cannot be eliminated entirely, you can solve
this problem by using some astronomical image processing software. These software will replace that
column with the average value of its surrounding columns.
Aside from the columns we just talked about, you may see one or more black columns which is not full
sensitive to the light or it is dim to light. This is the defect column and it cannot be removed by dark frame
calibration.
The following image shows a typical "defect" columns caused by a hot pixel, which is not very bright and it
is usually not considered as a defect column. It will be gone after dark frame calibration.