Solar imaging – 15/12/14

Around midday today, I noticed that the sun was shining through with patches of clear sky. Hence I thought I would do some more solar imaging. And I was richly rewarded, as the seeing was very good indeed. Today it was very easy to tell when the sunspots are in perfect focus.

And with so many different sunspots visible on the sun today, it would be interesting to see what sort of results I would get. I used my Olympus E-P5, with Skywatcher ED100, Baader Herschel Prism with double-stacked Baader Solar continuum (with the outer filter tilted slightly to minimise reflections and improve contrast), Televue 2.5x Powermate, and all mounted on Astrotrac TT320X.

The images I managed to get are amongst the best I have achieved so far. The best 23 images were imported into Registax 6 and the best 60% were stacked to get the final result below. The results are much closer to the solar images on the web taken with the Baader Herschel Prism; the granulation on the sun is clearly visible. Now I just need to wait for the Televue 5x powermate to arrive, and I should be able to get much larger images of these sunspots.

Multiple sunspots visible today
Multiple sunspots visible today
Sunspots AR2242 (larger) and AR2237 (smaller)
Sunspots AR2242 (larger) and AR2237 (smaller) 100% crop
Sunspot AR2235 on left and AR2237 on right
Sunspot AR2235 on left and AR2237 on right 100% crop
Sunspot AR2236
Sunspot AR2236 100% crop
Sunspot AR2239
Sunspot AR2239 100% crop
Sunspot AR2240
Sunspot AR2240 100% crop
Sunspot AR2241
Sunspot AR2241 100% crop

I have to say that I have been experimenting with the Baader Solar continuum double-stack, as the two filters are very different. The one which came with the Baader Herschel prism has one side which is gold and one side which is silver.

Using the filter with gold side towards the telescope produces images with better contrast. Similarly, by trialing different angles of tilt of the outer Solar continuum filter (mounted on the end of my Olympus 75mm F1.8 lens), I’ve managed to find the right angle which improves the contrast of the image.

Interestingly, using the two filters stacked parallel to each other in front of the Olympus lens resulted in lower contrast than with just one filter. The Baader double-stacked 1.25″ solar continuum filter does have one filter held at an angle to the other – so I am just trying to mimic this with my setup. I’m pleased with the results I’ve managed, now that it is set up optimally. But it is the seeing which is the most important to achieve the best results.

Boon