|Elevation above horizon
approx 23 deg 37 min.
I had a go at processing my first web cam shots, Mars of course. The
following was arrived at with much trial and error, saving good resulting
images as I progressed. I basically tried every thing I could think of
that would give the desired result. K3CCD Tools used for capture and stacking.
Stack of best frames from an AVI file taken with Toucam pro. Original
exposure was 1/33 second, auto colour, brightness set to approx 2/3, gamma
mid, saturation mid. Full resolution, capture at 5 fps. 1012 frames captured.
Top 10% stacked using planet wizard. This image showed misalignment of
the colours due to atmospheric dispersion. This was compensated for to
a small degree by offsetting the image from the centre of the field so
that the projection lens refracted the different colours slightly in your
favour. The result may be very marginal and you may not be able to tell
the difference, it depends on your equipment. In K3CCD the resulting stacked
image was saved as red green and blue 16 bit fits files. These were then
imported into Astroart. The green and blue frames were then blinked with
the red frame and some small adjustment made to the alignment to reduce
the colour fringing and separation caused by the atmosphere. Each colour
frame was then subjected to the following processing. A heavy unsharp
mask using a radius of 6 pixels and contrast setting of 4. A low pass
FFT filter to smooth out some of the roughness introduced by the unsharp
mask. The contrast was then stretched and manipulated to balance the colour
better and to highlight detail. Further processing was then carried out
to try to enhance the detail further and to smooth out the blotchy appearance.
A median filter set to 3x3 pixels and 6% to reduce white speckles. A high
pass FFT filter to enhance detail further. An erosion filter to smooth
out the noise introduced by the detail enhancing processes. The contrast
was then manipulated again to colour balance and show detail.