If you want to photograph the analemma -- the yearlong pattern the sun etches in the sky as the Earth orbits around it -- there are lots of things to worry about.
Forty-year rainstorms, unstable cameras and balky batteries -- these are just a few. Ask Anthony Ayiomamitis, who has encountered all of it.
Fortunately for Ayiomamitis, he walked away from the experience with nine complete photographs of the phenomenon -- well more than what he needed to become the eighth known person in the world to have ever photographed a perfect solar analemma.
Ayiomamitis, a retired Greek systems design consultant who has made astrophotography his full-time job, and the seven others managed to capture on film the figure-eight pattern that the sun makes as its position in the sky slowly shifts over the course of a year. The phenomenon is the result of the Earth's tilted axis and its elliptical orbit around the sun. And though astronomers have long known about the pattern, it can only be seen by taking a photograph of the sun at the same time every day for an entire year.
The first such photograph -- or rather, series of photographs all on one frame of film -- was taken by Sky & Telescope magazine editor Dennis Di Cicco between 1978 and 1979. The result is a luminescent figure-eight in the sky, with one loop slightly larger than the other.
Measuring the height of the figure can help amateur astronomers confirm that the Earth is indeed tilted on its axis by 23.45 degrees. Measuring the width at different points reveals how the Earth travels past the sun at different speeds depending on the time of the year.
"(An analemma photograph) is certainly something that the scientific community regards very highly, for the camera is able to capture something passive and subtle which our eyes cannot appreciate from day to day, and certainly not over the course of a year," said Ayiomamitis. "It documents the dynamics of the universe and how changes, slow or large, can be explained using scientific observation and logic."
What makes capturing the analemma on film so difficult has more to do with photography than with astronomy. Photographers must commit to returning to the same location every several days over the course of an entire year. And because all the shots must be taken on the same film frame, any one mistake can ruin all the previous shots, no matter how perfect they were.
Also, the photographers must ensure that they can set the camera up in the exact same spot on each visit or mount it permanently at the selected location. And they must press the shutter within seconds of the scheduled time, or else that particular image of the sun will be out of line with the others.
Most of the time, errors in the process are not discovered until the photographer finishes the project after a year and takes his film into the darkroom to be processed.
"The problem is that there are many things that can go wrong and a single instance of Murphy's law during the yearlong marathon is sufficient to kill an effort to capture this phenomenon," said Ayiomamitis. "If the film moves within the camera chamber, we have a wasted effort. If the camera is not oriented perfectly and the analemma at some point during the year eludes the field of view, we have a blown effort. If the camera fails -- like the electronics, the battery, etc. -- we have a wasted effort."
Even if a photographer manages to control all these variables, weather is still a factor to worry about. Waiting a week or more for clouds to disappear can leave gaps and ruin an otherwise perfect analemma pattern.
"For that year, I was watching weather reports carefully," said Steve Irvine, a potter and amateur astronomer who photographed the analemma from a farm in Canada. "Two-day forecasts are OK, but five-day forecasts are hit-or-miss. I ended up deciding that if the sun was out on the day before my scheduled day I would just take the picture then. It was kind of like bird-in-the-hand thinking."
Another big obstacle was the temptation to skip a photo opportunity, especially on mornings when the ground was covered in several feet of snow, said Irvine.
"After doing it for a couple months, you can get a little complacent," he said. "Even after taking your 30th image, you have to stay focused."
But with all the inherent challenges, the photographers didn't hesitate to throw in a few of their own. For instance, Irvine captured the image of the foreground scenery for his analemma shot on the same frame as his images of the sun -- a risky maneuver that could have ruined the frame, had it been underexposed or overexposed. (The foreground is generally blocked out with a filter when taking images of the sun so that it is not overexposed or blurry on the resulting photograph.)
Ayiomamitis, on the other hand, avoided that problem by taking the foreground images on a separate frame, after he had taken the images of the sun, and then using Photoshop to bring the two together.
He did, however, take it upon himself to photograph the analemma at not just one time of the day, but rather at 11 different times as part of a set that shows the position of the sun changing from sunrise to sunset. An additional image shows two analemmas on one frame of film.
Making it a point to begin each photograph in January and end the series in December, Aviomamitis effectively captured the full analemma in one calendar year. Photographers in the past have started in the middle of a year, causing them to finish the series in the following year.
In Athens, Ayiomamitis successfully photographed the analemma at eight different times of the day so far for his full-day series. He has three more to go before he completes his goal. If he fails, he'll have to wait until the following January to begin again, by his own rules.
Despite the difficulty of it all, he encourages others to give it a try -- especially from regions of the globe where the analemma has not yet been photographed. Because each region has a different view of the sun, the photographs will be unique.
"We do not have any examples of the analemma from the southern hemisphere, where the analemma would be inverted, where the larger loop is up top and the smaller loop is at the bottom," said Ayiomamitis.
"Similarly," he added, "we do not have any examples of the analemma from someone around the equator where the early morning and late-afternoon analemma would be perfectly horizontal." Such a photograph would show one half of the analemma above the horizon while the other half would be hidden below it.
"To this end, this work would be a great motivator for someone," said Ayiomamitis. "However, it should be emphasized that this is a very difficult challenge which requires huge amounts of patience, perseverance and advance planning and discipline, not to mention some good luck."
