Solar Can photographs capture the path of sun over Stewartby


An amateur astronomer from Stewartby has shared incredible photos of the path of the sun, taken over a year using a pin-hole camera mounted on the side of his house.

Darren Jehan captured the images using a Solar Can camera and then scanned the film into his computer to refine the results.

He told the Bedford Independent that it was only when his son was gifted a toy telescope in 2004 that his interest in the solar system was piqued.

“As a boy, I had a passing interest in the moon and planets, but never serious enough to own a telescope,” he said.

“It wasn’t until my father-in-law gave our young son a very small, plastic telescope toy that an interest was rekindled. Shortly after, I saw a telescope display in a store as we were Christmas shopping and made a comment along the lines of “Wouldn’t it be interesting to look at the moon…”.

Taking the hint, his wife bought Darren a small table-top telescope, and on Christmas night 2004 he saw Saturn (“Well, a dot with ears, but it was unmistakably, Saturn! That was it – I was hooked!”).

The following year, Darren began experimenting with astrophotography and fast-forward 20 years and he now has his own observatory and imaging equipment. He is an administrator on the world’s second-largest astronomy online forum (StarGazers Lounge) and an active member of both Bedford Astronomical Society and Letchworth and District Astronomical Society.

Describing his hobby, Darren said: “I really enjoy showing people the wonders of our night sky.”

However, imaging the Sun is very different to taking pictures of the night sky as the Sun is so much closer to Earth and gives off huge amounts of energy.

“Hopefully many people saw the recent Northern Lights display – these are charged particles ejected from the Sun in huge explosions that race across the 93 million miles between us and crash into our atmosphere,” said Darren.

“Thankfully, our magnetic field protects us, and channels this energy down along the magnetic field lines. As it does so, we see the energy being released as colours in the sky.

“Imaging the Sun can be dangerous – the basic function of a telescope is to gather light and bring it to a focus point. If you do that to the Sun’s energy, you can damage your eyesight permanently, and quickly.

“I should stress to anyone and everyone that you should never, ever, look at the Sun with any sort of telescope, binoculars or lenses. Astronomers who take pictures of the Sun, do so with very specialised equipment that blocks more than 99.9% of the Sun’s energy, not just the visible light.”

For this reason, the Solar Cans that Darren used to capture this image are a safe way to understand some of the mechanics of the solar system.

The Solar Cans in situ. Image: Darren Jehan
The Solar Cans in situ. Image: Darren Jehan

“The Earth is tilted at approximately 23.5 degrees to the Sun, hence we get the different seasons as we orbit our star,” he explained.

“For the Northern hemisphere, we are tilted towards the Sun during the Summer months, and away from it during Winter. The Solar Can records the path on the Sun over a period of time, clearly showing us the different heights the Sun reaches during the year.

“The lower paths are in Winter, and the higher ones are produced in Summer. The brighter the line, the sunnier it was on a particular day.”

How they work

Solar Cans are simple to use and have a piece of photo-sensitive film inside them and a pin-hole in the side. There is no focusing, no working out how long an exposure to take – just mount the can somewhere suitable, uncover the pin-hole and wait!

The cans can be purchased from various astronomical retailers, and come in different sets and different colours of film. Once you have finished exposing the can, you open it, take out the film and scan it into your computer and then use graphics applications to process and refine the images.

“Of course,” said Darren. “You don’t have to leave them for a year, like I did, but the longer time you leave it, the greater the variation in the arcs height on the final image.

“I will certainly be buying some more to play with, perhaps being a bit creative on positioning the cans!