The sun moves across the sky at 1° every 4 minutes but is only ½° in diameter, so any alignment of stationary observer, two mirrors and sun will only last for 2 minutes between the sun’s right limb entering alignment and the left limb leaving it.
In the present case the second mirror – the loch surface – is rippled so the actual time of alignment could be extended slightly both before and after the real alignment.
The 5 photographs were all taken by Mr Preston within a period of 2 minutes. My video was taken from a moving boat and so the alignment only lasted for a few seconds, allowing the genuine observation of something like a beluga whale surfacing briefly.
