Diffraction spikes

[Orion]

Ok, these are the images that I took last night with the new mask.

[Orion]

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[Orion]

3

[mch62 (Mark)]

Are the 6 diffracton spike a result of the Hartman mask or do you have a 3 vane spider?

Mark

[Orion]

I have a 4 vane spider so I'd say it's the result of the mask, it makes focusing easy enough.

[[1ponders] (Paul)]

Beaudiful Ed.

Looks like pretty perfect focus to me. One think I've notice now that I've seen them on a number of different appature telescopes is the wider the App the sharper and more defined the spikes. though I'll have to do an experiment up here on one night with a number of scopes to judge how much impact seeing condition have.

I might get the chance in the next month to try it with a 4" refract 5" Nexstar, my 8" meade and the 11' Celestron, all on the same night. (I'd better get building some smaller masks) If I manage it I'll post the images for a comparison.

Thanks for the chance to see your results.

ps Mark the diffraction spikes are a result of the triangular shaped holes in the mask.

[Orion]

Maybe it has something to do with the way the triangles are facing making the spikes look nice and sharp (they are all pionting in wards)
As you said Paul on one of your posts the biggest part of the triangle is on best part of the mirror. And a bigger aperture always helps.

Ps: The spikes looked a lot longer on the laptop.

[[1ponders] (Paul)]

I've just gone back and checked my previous posting and reached a subjective conclusion that the seeing conditions play a big part in the clarity of the triangles, (will check by experimenting). With your image triangles they appear to be all pointing outwards (?) the closer you get to focus, with mine thay appear to be pointing inwards, yet we end up with the same pocal image.

Unfortuantely I've deleted the original avis and stills so I'll hopefully do a few tonight (#@%& weather permitted) and get back with the results

[rumples riot]

I had the same result last night, seeing was very good and I had six diffraction spikes, great idea that you brought to the table there Paul. And; the spikes were really noticable even on the laptop. Good one, really think it is a great idea.