Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Kenny on Apr 05, 2015, 22:09:54

Title: Solar Mosaic from today
Post by: Kenny on Apr 05, 2015, 22:09:54
21 pane mosaic (lots of overlap) of the Sun today. I had to wait most of the day before the cloud cleared and managed to get 20-30 minutes observing and capture time in before the Sun set behind the clouds and local buildings.

Coronado Solarmax 60 solar scope on HEQ5 mount solar tracking. 21 x 30 second AVIs in grayscale captured with Celestron NexImage Solar System Imaging CCD Camera and x2 Barlow lens in SharpCap2. Videos stacked and auto-sharpened in AutoStakkert2. Photos merged in i-Merge. Recoloured, and small curve adjustment to brighten the prominance, in Photoshop CS2.

Having some difficulty working out the orientation as Active Regions don't show up as well as they do in Baader AstroSolar filters. If you have any clues let me know. :)

(https://farm8.staticflickr.com/7646/17020126806_28d78ff44f_b.jpg) (https://flic.kr/p/rW1AJb)

Title: Re: Solar Mosaic from today
Post by: JohnP on Apr 06, 2015, 18:52:00
Nice - looks like there is some slight colour variation across disk but looks very good - John
Title: Re: Solar Mosaic from today
Post by: Carole on Apr 06, 2015, 22:55:19
Ditto to what John says.

No stopping you now Kenny.

Carole
Title: Re: Solar Mosaic from today
Post by: Kenny on Apr 07, 2015, 00:00:25
Yes, the colour variation is the way i-Merge blends. I'm figuring out it depends what order you click to align each layer to other layers, almost as if it promotes the last layer to the top. I also think it brights areas that have more layers overlapping. For example, one of the versions of this had a really bright, overexposed "spotlight effect" in the centre of the image. Saying that, the results with i-Merge are fantastically better than I've managed to get out of Photoshop or Microsoft ICE.

I think I might have another go at this one to see whether I can get rid of the gradient.

I really like the fact that with a mosaic I get a whole disc with lots of detail.

Finding it difficult to get solar prominences during the capture process without over-exposing the surface. It's similar to the challenge with Jupiter vs the jovian moons.

It's all a learning process. I'm very pleased with the results, working with the limitations of the NexImage which is really only an entry level camera, but can also see the oportunities for improvement. :)
Title: Re: Solar Mosaic from today
Post by: Carole on Apr 07, 2015, 08:09:18
Kenny, I think the prominences are captured separately and then you overlay the overexposed Solar disc with the correctly exposed disc.

Carole