Seems a lot of us photographers believe that the sun’s rays are routinely twisted by the atmosphere in such a way that distorted remnants of the sun’s orb are still visible for a brief period after it has gone past the horizon line.
Yesterday I went on a fools errand to Point Reyes to shoot some pics. Fools errand, because I did not stop to think that access to most of the prime national park spots would be closed due to government shutdown. I found myself on a hill overlooking the ocean in the company of 4 or 5 cars with people improvising their day out, sitting on the roofs of their cars meditating on the magic of the moment.
In fact you could not imagine a more perfect still silent new age Californian vigil. It was unusual that things were so becalmed- – not a whisper of air – - so unusual so close to the ocean. Not a word was spoken by anyone. It was as if any utterance could cause the universe to change its mind about existing.
On the ocean lack of haze was quite normal for this place. But the lack of air movement meant that visibility was even better than normal. One could see a stunning amount of detail such a birds many miles out and patches of floating kelp. A shame there were no whales around – they would have been so easy to spot .
The sun seemed to go behind the horizon and then it seemed that we were left with an incongruous sun band squashed into a line on the horizon. It was subjective but that band appeared to persist for many minutes longer than it should have done given the sun’s earlier rapid dash for the horizon.
Musing on all that, on the winding dark road home, I decided to apply some simple arithmetic to the matter (time of shooting in the EXIF and correlate something close to the actual sun’s position in the sky, excepting air and distortion).
Naively I was convinced I was about to demonstrate some evidence for my notion that interesting mirage effects had been at work, permitting us a magic last minute view of the sun even after it had gone. I felt certain on the basis of subjectivity that there was no question that this light was being bent right around the horizon. .
To my big surprise, I saw that this was not happening - the squished band must have been present before the sun had actually cleared the horizon.
Somehow it seemed that more kudos accrues to the viewer to still see something which is ‘gone away’ – as opposed to seeing something which is simply veiled or obscured. This was the little emotional bubble which I burst with my test.
Here is a gallery sequence which shows the sun going down and overlaid a circle which gives a rough idea where the sun would have been had there been no distorting atmosphere (according to my crude estimate).
This estimate clearly is very inaccurate because the sun images which defined my base rate of the descent of the sun were already subject to distortion of the atmosphere. The sun’s image is already compressed in the first image. I did not know precisely when the photos were taken. The camera date was never precise and furthermore it had been adjusted after the shoot.The only accurate timing data I had was the interval between the photographs.
Naturally no self respecting scientist nowadays would use such poor data and crude methodology to prove anything useful - but my intention was pretty simple. I wanted only to know whether the sun was present in the sky or had it actually disappeared over the horizon when the last tantalizing distorted remnants were still visible. The data I collected at least accurate enough to show that this was simply not happening.
I could certainly improve on this by shooting a few more photos of the sun, with the identical focal length lens at intervals, but when the sun is high in the sky and not subject to the same level of atmospheric distortion.
I intend to do this some time soon and compare the rate of descent to that which was calculated in the above gallery.
Of course there is still nearly zero scientific merit to this – even if I improve the accuracy a lot – but there is some satisfaction in trying to extend ones self using only the technology one holds in ones hand. In this case it was my camera and a set of photos.
Just so this does not look like a dry quixotic tech exercise alone, here are 4 regular pics from the outing. One merely has to look at them.