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Old 09-03-2012, 09:40 AM
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bojan
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Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 6,170
Guys,
with lenses at F2.. F4, microns are significant, not to mention millimetres.
You simply have to have some extra room to move focus in and out to be sure you are spot on.
Some lenses are too short for EOS (which is quite deep - that is why I went into all the trouble with modification of those FD lenses, as mentioned earlier).
Often, with some skill and determination, a missing 0.1 millimetre can be adjusted by moving the focus stops a bit (that depends on particular lens design).

The tilt of the lens (or sensor) can be fixed by gluing a layer or two of Al foil to a camera flange on the appropriate side.
http://www.astrosurf.com/buil/tilt/test.htm

Last edited by bojan; 09-03-2012 at 10:06 AM.
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