Analemmas from Viterbo Airport, Italy

April 25, 2023


Tre analemmi Meniero firmata

Photographer: Marco Meniero  

Summary Author: Marco Meniero    

The analemma is the orthographic projection of the apparent motion of the Sun on the plane of the local meridian; it’s used to determine the height of the stars, in particular that of the Sun. Analemmas are thus useful for building sundials (also called quadrants or analemmatic clocks).

When looking at sundials a curve in the shape of an "eight" can be seen that intersects the hour lines. This curve is called the analemma or lemniscate. However, using a photographic trick, the analemma can also be seen projected in the sky: The result allows the viewer to see the "eight" curve projected onto the sky in a southerly direction.

Following this idea, I created a photographic composition by joining the analemma curve with two other curves created with the same technique but at different times: The one on the left at 07:20 UTC and the one on the right at 15:00 UTC. Furthermore, on the day of the winter solstice I resumed the path of the Sun throughout the day. You can see the curves close to twilight strongly inclined unlike the one at the "meridian" which is vertical.

I took the photos for these three curves from the Viterbo Airport, Italy.

Technical data for the analemma curve: Filming started in early March 2022, filming ended in early March 2023. Filming frequency: On average one shot every 15 days, with minimum intervals of 7 days and maximum of 20 days, based on cloud conditions. Shooting times: 07:20 -11:10-15:00 UTC

Photo details: Nikon Z9; ISO 32; Nikon S14-24/2.8 lens closed to f/22; 1/32,000th to 1/8000th second exposure, depending on sky conditions; 80 photos of the solar disks were taken, but only 68 were used.

Viterbo Airport, Italy Coordinates: 42.22.228N, 12.05878

Technical data for panorama: Taken on 1 November 2022, 11:10 UTC. 

Photo details: Nikon Z9 camera; ISO 32; Nikon S14-24/2.8 lens closed to f/6.2; 1/160 second exposure; sum of two 360-degree panoramas of 12 shots each, one on the ground and one on the sky. The pan has a range of 360 degrees in azimuth and 130 degrees in elevation. Photo processing with Photoshop. Study of the analemma with Starry Night 8. Having taken both the panorama and the curves with the same focal length (14mm) made it easier to maintain the heights and azimuth angles of the curves.

Arcatelle Aqueduct, Italy Coordinates: 42.258649, 11.815915


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