Instrument and weather
The same sighting through an eye, an Instamatic and a reflex; a storm; an airliner on a long exposure. 5 reconstructions, none of them a video: each is computed while you watch it.
One sighting, three instruments#
The same account, the same second, the same sky — changed in one field. What an observation was made THROUGH decides the geometry of every frame, and the three below differ in nothing else. Note also what each one lets you set: an Instamatic's owner had one aperture and one shutter speed, so the editor offers them nothing to choose. A reconstruction can only be as rational as the settings it permits.
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Seen with the naked eye
An eye perceives an angle as an angle wherever it falls, so the image is equidistant and a ruler held to the screen means something. 60° tall, and no frame at all: an eye has no rectangle.
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On 126 film, 1964
A SQUARE frame 36° on a side — 28 mm of image behind a 43 mm lens. One aperture, one shutter speed, one focal length, all fixed: nothing to set, and nothing offered.
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Through a 50 mm lens
27° tall, which is why a photographed light so often has nothing recognisable beside it. A lens maps f·tan θ: everything off-axis is stretched, 42% at 33° from the centre.
Weather, and the instrument#
The two things that most often turn an ordinary object into an extraordinary account.
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A thunderstorm
Cloud base at 600 m, heavy rain drifting on a 5 m/s wind, lightning lighting the clouds and the whole scene, thunder arriving as late as its distance makes it. Pause it: all of it stops.
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An airliner on a 20-second exposure
What is seen is an airliner on final approach, its landing lights facing the lens. Pause it and the 20-second exposure develops: steady lamps draw lines, flashing ones drop dots, and their spacing is the angular speed divided by the flash rate.