Bahtinov mask with a PST?

[ScubaMike]

Hi All,

I have been successfully using a bahtinov mask to help me get good focus when using my C925 on planets.

Now that I have started to take solar Ha images (using a PST.... not the C925 ), I wondered if anyone had tried using a bahtinov for focus on the sun?

I would usually use a point source (like a moon of jupiter) to get the spikes, but am unsure if the spikes would still be good when using a visible disk.

Any information (including "won't work") gratefully received.

[Merlin66]

"Won't work" ;-)

The Bahtinov mask relies on a pinpoint object/image ie a star, to generate the diffraction spikes.....

[michael.h.f.wilkinson]

I doubt this would work. the disk of the sun is so wide it would widen the spikes to the degree it would become pointless.

[DirkSteele]

Afraid it will not work. You require point sources.

[andrew s]

However, I did use a "twin hole" mask to good effect. You get two images of the sun which come together as you reach focus. I would look at the edge of the sun rather than a solar feature. I then did trial and error about this point. I was using an SM40 and 5mm holes in the mask. Andrew