Telescope: Skywatcher 8" f/5 Newtonian
Focus: Prime focus
Camera: SAC7B, uncooled
Exposure: 93 x 25s
Date: 3rd May 2003
Processing: Acquired in K3CCDTools as
AVI. Stacked in Iris. YRGB image, composited in Photoshop.
Colour enhanced using Multiple Luminance Layering.
Processed using the YRGB technique. During the later
stages of curve stretching in Photoshop the brighter stars were prevented
from bloating by de-selecting them. Artifacts from this are mostly not
apparent except for the pair of stars at the bottom right just above the
caption, where some halo is visible.
Some of the characteristic diagonal banding noise from the
SAC7 camera is visible in the brighter regions just outside the galaxy core.
In this case no wavelet processing was applied to reduce this noise as it
wasn't too bad.
The image has some colour information, but star colours
are mostly not apparent. Also the red colour in regions of nebulosity
in the arms of the galaxy did not appear. Perhaps I could have done
more to increase colour saturation.
Unsharp masking usually results in stars getting
unpleasantly sharp with a dark ring in extreme cases. In this image
the bright stars were de-selected in Photoshop (using the Magic Wand), and
unsharp masking was applied to the rest of the image. The selection
was then inversed and so gaussian blurring was applied to soften out the
Full details in the
Image Processing section.