Starlight Xpress SXVR-H36 - Manual (Page 8)

Handbook for the SXVR-H36 Issue 1 June 2009
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2) Does the software indicate that the camera is successfully connected? An attempt
to take a picture will fail with an error message if the USB is not properly installed. In
this case, try unplugging the USB cable and then reconnecting it after about 5
seconds. Restart the camera software and see if it can link now. If not, check in
Windows device manager (via ‘System’ in ‘Control Panel’) and see if the
BlockIOClass device is installed properly. If all looks OK, try checking the ‘Disable
VID/PID detection’ in the ‘Set program defaults’ menu and try again.
3) If you cannot find any way of making the camera work, please try using it with
another computer. This will confirm that the camera is OK, or otherwise, and you can
then decide how to proceed. Also check on our web site to see if there are any updates
or information about your camera software that might help. The message board might
prove useful to ask for help with getting your camera operating properly.
Our guarantee ensures that any electrical faults are corrected quickly and at no cost
to the customer.
Enhancing your image:
Your first image may now be reasonably good, but it is unlikely to be as clear and
sharp as it could be. Improved focusing and exposure selection may correct these
shortcomings, and you may like to try them before applying any image enhancement
with the software. However, there will come a point when you say, ‘That’s the best
that I can get’ and you will want to experiment with various filters and contrast
operations. In the case of daylight images, the processing options are many, but there
are few that will improve the picture in a useful way.
The most useful of these are the ‘Normal Contrast Stretch’ and the ‘High Pass Low
Power’ filter. The high pass filter gives a moderate improvement in the image
sharpness, and this can be very effective on daylight images. Too much high pass
filtering results in dark borders around well-defined features and will increase the
‘noise’ in an image to unacceptable levels, but the ‘Low Power’ filter is close to
optimum and gives a nicely sharpened picture.
The ‘Contrast’ routines are used to brighten (or dull) the image highlights and
shadows. A ‘Normal’ stretch is a simple linear operation, where two pointers (the
‘black’ and ‘white’ limits) can be set at either side of the image histogram and used to
define new start and end points. The image data is then mathematically modified so
that any pixels that are to the left of the ‘black’ pointer are set to black and any pixels
to the right of the ‘white’ pointer are set to white. The pixels with values between the
pointers are modified to fit the new brightness distribution. Try experimenting with
the pointer positions until the image has a pleasing brightness and ‘crispness’.
At this point, you will have a working knowledge of how to take and process an
SXVR-H36 image. It is time to move on to astronomical imaging, which has its own,
unique, set of problems!
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