I use a home-made curved spider in my 4.25" f/5 and have no spikes. Thought I would try it before I went with an optical window, just to satisfy my own curiosity, and it worked so well, I never used the window (have a couple of surplus windows from Edmund Astroscans). What I'm told is that the total resolution loss due to diffraction from the curved supports is still there, just not visible as spikes since it's spread-out to a level below the threshold of visibility. I don't think Protostar offers a curved option for large spiders, however. I'll check into it as time permits. --- Michael Carnes <MichaelCarnes@earthlink.net> wrote:
It's the 2-legged curved holder and I think it's really great. Some people love diffraction spikes. I hate 'em, and they're gone.
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