Handbook for the SXVR-H694C
Issue 1 March 2012
7
Point the lens or pinhole towards a well-lit and clearly defined object some
distance away. Now enter the ‘File’ menu in the H694C software and click on ‘SX
camera interface’. Select an exposure time of 0.1 seconds and press ‘Take Photo’.
After the exposure and download have completed (about 4 seconds) an image of some
kind will appear on the computer monitor. It will probably be poorly focused and
incorrectly exposed, but any sort of image is better than none! In the case of the
pinhole, all that you can experiment with is the exposure time, but a camera lens can
be adjusted for good focus and so you might want to try this to judge the high image
quality that it is possible to achieve.
Various other exposure options are available, as can be seen in the picture above. For
example, you can ‘Bin’ the download 2x2, or more, to achieve greater sensitivity and
faster download, or enable ‘Continuous mode’ to see a steady stream of images.
‘Focus mode’ downloads a 128 x 128 segment of the image at high speed. The initial
position of the segment is central to the frame, but can be moved by selecting ‘Focus
frame centre’ in the ‘File’ menu and clicking the desired point with the mouse. The
focus window has an adjustable ‘contrast stretch’, controlled by the 12-16 bit slider.
The image will be ‘normal’ if 16 bits is selected, while setting lower values will
increase the image brightness in inverse proportion.
If you cannot record any kind of image, please check the following points:
1) Ensure that the power indicator lamp is on and that the cables are properly home
in their sockets.
2) If the screen is completely white, the camera may be greatly overexposed. Try a
shorter exposure time, or stop down your lens. See if covering the lens causes the
image to darken.
3) If the USB did not initialise properly, the camera start-up screen will tell you that
the connection is defective. Try switching off the power supply and unplugging the
USB cable. Now turn the power supply on and plug in the USB cable. This will re-
load the USB software and may fix the problem after restarting the SXV_hmf_usb
program. Otherwise, check the device driver status, as previously described, and
re-install any drivers which appear to be defective.
4) 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 faulty, and you can
then decide how to proceed. Our guarantee ensures that any electrical faults are
corrected quickly and at no cost to the customer.
As the H694C is a ‘Single-shot’ colour camera, the full resolution raw image will
show a fine grid pattern, due to the RGB colour filters on the CCD chip surface. This
is normal and will disappear once the image has been converted to colour by the
software. Unlike commercial digital cameras, astronomical colour cameras do not
normally output a colour image directly. This is so that various image corrections can
be performed on the raw data (e.g. dark frame subtraction), as these are impractical
after conversion to colour. Also note that binning the raw image at anything other
than 1x1, will destroy any colour information and so output only monochrome
images.
