'Amazing and dynamic': Chch photographer capturing the sun in all its glory

Visiting the sun is impossible, but for a New Brighton amateur astronomer his forays into the boiling 5500 deg C cauldron of the corona layer of the sun’s atmosphere are done photographically.

When asked why, Sai Shankar, a teacher assistant at Allanvale School in Bryndwr, said he loves all kinds of astro-photography: “But I especially like photographing the sun.”

“We forget the sun is a star, just like all the other stars in the sky, so when you look at the surface of the sun you are looking at a star.

“It amazes me that we are living in a time when we can do something that’s been out of reach of most amateurs photographers up until now.

“With the help of an ordinary refractive telescope and some affordable specialist equipment we can now see the sun up close, it’s quite an experience to look at it with your own eyes,” he said.

New Brighton amateur astronomer Sai Shankar loves recording the activity on the volatile surface...
New Brighton amateur astronomer Sai Shankar loves recording the activity on the volatile surface of the sun. PHOTO: JOHN COSGROVE
Shankar said it’s all achieved by using specialist filters and some free online software.

“We start off with a white light filter which lets all the colours of the visible spectrum through, but reduces them down to a tiny percentage, less than one per cent of what we see.

“This filter shows us the photosphere of the sun, the layer of the sun with all the sun spots happening on it.”

Next he uses is a hydrogen alpha optical filter designed to transmit only a narrow bandwidth of light.

“This filter only lets in a wavelength of light that is less than one nanometre in size; a human hair is 600,000 nanometres in thickness.

“It gives me amazing views of a different layer of the sun’s atmosphere, now I can now see the chromosphere,” he said.

This layer has the temperature ranging from 6000 deg C to about 20,000 deg C.

“You can still see sun spots but you can now see prominences exploding on the edge of the sun plus a lot of surface detail.

A big prominence exploding on the north east limb of the sun, estimated to be as high as five or...
A big prominence exploding on the north east limb of the sun, estimated to be as high as five or six earths. PHOTO: SAI SHANKAR
“It looks amazing and it’s dynamic, over an hour it can change immensely,” Shankar said.

Using a monochromatic video camera that captures at 100 frames per second, he then records 30 seconds of imagery at a time.

“The atmosphere of the sun is quite turbulent so it’s called ‘lucky photography,’ as over that 30 seconds there will be brief moments of clarity in the surface turbulence.

“On screen, your watching blurry images then suddenly it jumps into clear sharp focus,“ he said.

Free photographic stacking software quickly sorts the best one-to-five per cent of all the images captured to produce a clear, sharp result as a mosaic.

“It finds the best frames and matches them together into a black and white image which I can then colourise to show the sun.”

From there Shankar said he will manipulate with them in Photoshop and produce the images he is becoming well known for.

Shanker said he plans to display his unique imagery online in the coming weeks.

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