...continued... Now, what about the shapes suggested by these images? We must not forget that the sail dimensions are 3x3 metres (10x10 feet). At a distance of 740km, this corresponds to an object of 1.5 m (5 feet) at the distance of the ISS during a zenithal passage. On the following image of the ISS, I have represented this dimension as a yellow square just above the ISS: http://legault.perso.sfr.fr/iss_nanosail.jpg This size is smaller than the size of the EF (Exposed Facility) boxy modules at the end of the Kibo lab (just above the yellow square). Since none of Ralf Vandebergh's ISS images show each of these modules with their shapes, or even simply separate them distinctly, there are all reasons to doubt that the shape of the sail is real. All the more that, as for the image of USA-129/KH satellite, we have no reference image or data that could tell us the real orientation (and the real color) of the sail at the moment of shooting. All serious imagers know that, to have a minimum of confidence in "details" shown by such images, in any case one raw image cannot be sufficient. Many raw images (dozens at minimum) must be combined and they must show consistent details. The result presented here is very probably a combination of various causes such as distortion due to turbulence, bumps of the telescope during manual tracking, Bayer matrix sampling effects, noise, compression, heavy processing etc., as illustrated in this page: http://legault.perso.sfr.fr/bad_astrophotography.html regards At 12:37 06/05/2011, Ralf Vandebergh wrote: >The image set shows how the color tones actually exist in the image. >Left is original color, right is auto-color correction, this process >increases contrast between the subtle color dyes. >http://freeimagehosting.nl/pics/562a0c0ea73a6b3811d80c3226860812.jpg Thierry Legault www.astrophoto.fr _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
This archive was generated by hypermail 2b29 : Tue May 10 2011 - 20:45:49 UTC