4 March AR12807, humble first WL with C8

[H-Alpha]

Hi all,

Yesterday morning there was a predicted seeing of ~0.95 in Athens. I am still waiting for my SSM to know the real one...

It was a good opportunity to test my only scope for WL: Celestron 8 (too large in aperture for usual solar seeing...), with Baader Astrosolar 3.8D filter, Baader Continuum filter and ASI290MM camera.

I took some 12 videos of 30 seconds at maximum size image (1936x1096) and ~140 FPS, resulting at ~4000 frames each. I kept only the best 400 of each capture through PIPP and passed them to Autostakker. Below I attached the best photo both as original and with some improvement in Photoshop (just Levels and a little bit of Smart Sharpening). I made no flats, since I do not know if absolutely necessary (no dust yet on all the new equipment :-) )

This is of course a bad image, but it's the first time I imaged the sun's granulation, so very happy for this! And always even better when we share it

I suppose that the seeing was my No1 enemy for such a large aperture, as many of you have highlighted in previous posts. However, if you see anything else I could improve with the current scope and filters, you are very welcome to comment.


All the best,
Alexandros

[MalVeauX]

Your seeing was rather good to generate that resolution and image quality at that image scale. So congrats! I think its very good image! And a very promising start on your journey through high res.

Very best,

[H-Alpha]

Thanks Marty!
Very encouraging words. :-)
All the best,
Alexandros

[MalVeauX]

Thanks Marty!
Very encouraging words. :-)
All the best,
Alexandros

For your next opportunity, try using a red filter (610nm~656nm) instead of a 540nm filter. 540nm is a shorter wavelength and has higher angular resolution, but it requires significantly better seeing conditions to record. You're already on an uphill battle with an 8 inch aperture, so to assist, especially starting out, try using red wavelengths.

656nm at 200mm, critically sampled, needs around 0.83 arc-second seeing.
540nm at 200mm, critically sampled, needs around 0.68 arc-second seeing.

The fact that you have discernible convection cells at this image scale with a 540nm filter with the 200mm means your seeing was pretty good, probably around 1 arc-second give or take a bit. So you're pretty close.

Very best,

[H-Alpha]

:-) :-) :-)

Following your previous advice Marty, I have already ordered and am waiting for:

Astronomik ASHA12nm - H Alpha CCD Filter, 12 nm
and
Baader IR pass filter 1.25" (685 nm)

Will try them as soon as they arrive and have good seeing. The next two days seem also <1.0 arc-second, but won't have the new filters yet.
Good days will come again for sure! :-)

Thanks once more!
Alexandros

[MalVeauX]

:-) :-) :-)

Following your previous advice Marty, I have already ordered and am waiting for:

Astronomik ASHA12nm - H Alpha CCD Filter, 12 nm
and
Baader IR pass filter 1.25" (685 nm)

Will try them as soon as they arrive and have good seeing. The next two days seem also <1.0 arc-second, but won't have the new filters yet.
Good days will come again for sure! :-)

Thanks once more!
Alexandros

You likely only need one of those; 656nm 12nm would be great for everything and at night if you wanted a night time HA imaging filter. Good for moon too. 685nm would be really for solar system. The baader solar film does pass IR. The 685nm will likely have just around half the transmission that no filter would have, roughly, but with ND3.8 it will still be plenty bright for high res imaging. If I had to choose just one, for solar, it would likely be the 656nm 12nm just because of overall usefulness for every subject possible. But 685 is a great tool to have too.

Very best,

[DeepSolar64]

I agree with Marty. That's a nice image! I would have been very satisfied with that one.

[marktownley]

Nice shot! I hope your actual seeing is what meteoblue says so you can utilise the large aperture regularly.

[H-Alpha]

Thank you both James and Mark!

Mark, cross fingers! I hope so. Three consecutive days with sub arc seeing as forecast is really giving hope.

I took some photos todays as well to test, but have not process them yet.

I am still waiting for my SSM to start measuring the seeing regularly and compare with the forecast. Due to covid19 (they said...) it is delayed somewhere between France and Greece :-( Frederic from AiryLab promised to send another one if I don't receive it by next week. It is really kind of him! I hope it arrives earlier.

All the best,
Alexandros

[JochenM]

Very promising indeed, Alexandros.

Looking forward to seeing more.

[Montana]

That's a fantastic start, well done

Alexandra