[Wavytone]

Bojan

I’ve seen that before. The way this works is by having curved edges, where the radius of the curve is the same as the semidiameter (ie radius) of the primary mirror. The result being light diffracted will contribute a circular diffraction pattern concentric with that of the mirror, and if done right, no spikes.

The basic principle is that a curved edge in the light path produces a circular diffraction pattern, which must reduce to a circle at the focus. Whereas a straight edge (conventional vanes) produces a straight spike.

The snag with that beastie however is the hideous obstruction incurred. By all means try it, though I suspect the end result will be worse, not better, than without it.

There is a better solution - a curved vane spider - which achieves same without the obstruction penalty.

Though I know you are well aware of the ultimate solution ...