Bahtinov Mask Wavey Diffraction Pattern

[ianaiken]

Hi all, tonight I hope is the start of the imaging season for me, up until now I've had no oppurtunity to point the scopes to the sky of test out my new OBS.

Anyway, tonight is here, the roof is off and scopes are imaging.

I have a strange diffraction pattern on my 80ED with Atik 314L+ though a Clr filter. Does anyone know what is causing this? It's the first time I have seen it on the 80 with this configuration.

[ollypenrice]

Presumably that's just abominable seeing, perhaps early in the evening while the land is giving up its heat? I may be wrong, though. I've certainly never seen anything like it.

Olly

[ianaiken]

Thanks Olly - On the scope right next to it the diffraction pattern is fine so I don't think so as both scopes have the same FOV, unless a cloud went past just as I was focussing this scope.

The only thing I have read that this could possibly be is the light not focussing at the same point. Maybe I need to use the mask on each filter and see what happens. I think my spacing is a tiny bit out maybe that has something to do with that as I never had this problem prior to fitting the filter wheel in tests that I have performed where I knew the spacing (and focus) was bang on, for instance in the IC1396 I managed to get during the Summer that I posted and you processed.

I guess I will have to do a bit experimentation (when it's not good enough for imaging).

So far I've got 6 hours of data in 3 hours elapsed on one mount so happy.

[ianaiken]

Hi Olly - Well tonight the diffraction pattern is fine with the Clr filter so you're right Olly. Seeing at that time must have been abysmal. I guess a cloud (it was patchy) since I didn't use the mask on both scopes in parrallel, it was sequential. I'm surprised I couldn't see it though maybe it was faint and hidden in the LP.