Sunspots
I was testing the solar filter for the camera, in preparation for Monday’s eclipse. We won’t be seeing the total eclipse, but I’m hoping to get some good shots of the partial.
As I was processing the results, I realized I’d captured sunspots! (Those dark spots in the upper left.)
Click to embiggen.
For those who wonder about such things, this was taken on the 100-400mm lens, fully zoomed to 400mm. ISO 640, f/10, with a 1/3200 shutter speed. I had to set everything manually, because the camera overexposed the shot if left to its own devices.
I think next time I’ll try to reduce the ISO down to about 100 and see if that gets rid of the minor graininess.
Processing involved cropping the shot, noise reduction, and an orange overlay.
Judy
August 16, 2017 @ 6:18 pm
I was trying out a solar filter on my tiny telescope last weekend and was amazed to see a great big sunspot. I thought it was a time of low activity. Seeing the sun was cool enough, but that made it even better.
Steven Kasow
August 17, 2017 @ 8:15 am
That graininess might be granulation, a feature on the sun itself; see http://www.skyandtelescope.com/observing/celestial-objects-to-watch/sun/sun-white-light-guide-nearest-star/ .
mjkl
August 17, 2017 @ 11:58 pm
Why the orange overlay?
Jim C. Hines
August 18, 2017 @ 8:47 am
mjkl – the filter produced a black and white image, and I liked it better in color. The overlay also brought out the shading at the edges, making the sun look more spherical.