Subject
Mars
Date
8th August 2003
Telescope or Lens
Celestron 9.25 SCT with Televue 3x Barlow
Mount
G11
Camera
Phillips Toucam Pro
Filters
NIR Blocker
Total Exposures L 1/33 sec R   G   B  
Sub exposure
Average of 100 frames
Binning
One shot colour 1x1
Field of view and resolution
0.16 Arcsec / Pixel
Comments  
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.