hi Fernando. That's looking good - should be producing pretty good high res images as it is.
Star test looks fairly similar to what I get. comments:
- looks like a little bit of TDE - does the ring pattern definition change from inside to outside of focus? If so, this is probably fairly typical of GSO optics, but not a big issue for low dynamic range (planetary) imaging - might possibly be worth masking outer few mm of the mirror, but only if the focused images show significant halo.
- something is intruding into the beam - guess it is the focuser (from your earlier published shadow projection). if focuser you can probably move the beam across to get rid of it by slightly varying the in/out position of the secondary (I think it has to go further into the tube) and recollimating - would be worth fixing. Check using shadow projection to make sure the OTA does not cut off the edge of the input beam. the diffraction patterns due to the spider supports are not central, which possibly supports the idea that the secondary is a bit offset.
- there is some blurring of the diffraction pattern on the upper side. either due to tube currents or slight mirror distortion due to adhesive back mounting. not too bad, but worth fixing if it is anything instrumental.
- not quite circular pattern. collimation looks pretty good from the position of the central spot, so suspect slight problem with primary edge mounting (assume that you have loosened off the 3 mirror locking lugs). Not major distortion, but would be worth tracking down and fixing.
Really looking forward to your report.
regards ray
Last edited by Shiraz; 18-10-2012 at 06:36 PM.
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