As has been stated, diffraction effects, or lack thereof in a Newtonian reflector, is mostly aesthetic. I have never been particularly bothered by the spikes coming off bright objects, but while building my daughters 8" f4 ball scope, we thought that it would be cool to do away with the spikes. We made a curved vane spider which consisted of one ~170 degree vane to which the secondary hub was mounted. The views were really great without the spikes and I really liked it. However, that vane wiggled like Santa Claus's belly any time the scope was touched. I worked, and worked to improve the design and did make some strides, but it just didn't perform well enough for me. Having to wait for a couple of seconds for the image to stop jumping around after touching the scope was just to much for my daughter, so we eventually swapped the limp spider for a tried and true, 4-straight-vane, solid as a rock spider. I have not seriously considered monkeying with a curved one since. I encourage people to do what is pleasing to them and if a curved vane spider is in your future, I can help you avoid some pitfalls. Mat -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Thursday, March 08, 2012 9:17 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] solar filter There are a lot of common misconceptions about the cause and effects of diffraction, Josh, It took me decades to sort it all out, myself, and I'm still learning. Thanks for bringing it up, actually. People spend a lot of time and energy trying to optimize an optical system that in the end only produces either marginal or purely subjective gains. On Wed, Mar 7, 2012 at 11:14 PM, Josh <mountaindrifter@gmail.com> wrote:
I can accept being wrong, but only if I learn something. :D
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