Starlight Xpress SXV-M25C User Manual
Page 19
Handbook for the SXV-M25C Issue 1 June 2004
19
4) The image will now look quite impressive and I hope that you are pleased with
your first efforts!
Further small refinements are usually possible and you will become expert at judging
the best way to achieve these as your experience increases. As a rough guide, the
‘Filters’ menu can be used to sharpen, soften or noise reduce the image. Strong ‘High
Pass’ filters are usually not a good idea with deep sky images, as the noise will be
strongly increased and dark rings will appear around the stars, but a ‘Median’ filter
can remove odd speckles (hot pixels) and a mild ‘Unsharp Mask’ (Radius 3, Power 1)
will sharpen without too much increase in noise. If you have a copy of ‘Paint Shop
Pro’, the ‘Edge preserving smooth’ filter will work rather well as a noise reducer and
the ‘Despeckle’ filter will remove warm pixels quite effectively. To use these, export
your image as a Tiff file so that Paint Shop can accept it. Paint Shop (or Photo Shop)
also provides a convenient way of cropping, rotating and printing your finished
images. The following examples are typical of 40 minute exposures at F5, using an
IDAS filter on an FSQ106.