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thanks gary for that.
i actually printed out the newt raytrace prog and in that print out it has the illuminated field at the focal plane. grrr...
interesting to note the Skywatcher 10" dobsonian (254mm primary) will illuminate:
8.5mm diameter @ 100%
35.6mm diameter @ 75%
of course this is a gradient from 100 -->75
another interesting thing that the tube is actually too small in its current format and blocks light at the 75% range... very interesting indeed!
To illuminate a 30mm diameter at 100% i would require a 2.5" focuser and a 70mm secondary! im thinking of hitting the prototyping lab and finding some bits and pieces...
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