Solarigraphy

A technique to capture the Sun's path on the sky during the year, using photographic paper and a pinhole camera.

2.2. - 23.3. 2023, Southern view

Another pinhole camera visible in the right part of the frame, near the TV antenna.

2.2. - 23. 3. 2023, Western view

Two other pinhole cameras visible om a row. Notice the stripes on the chimney near the west.

View from rooftop antenna. 16. 1. - 30.4. 2023

View from rootfop antenna. 2.2. - 30.4. 2023

16. 1. - 27.3. 2023

Indoor solariography, 14. 1. 2023 - 7. 4. 2023

23.3. 2023 - 10.6.2023

Sadly, the paper inside moved.

2.2. 2023 - 10.6.2023

Summer to winter, 2022

A 6-month solarigraphy, capturing all the various declinations of the Sun. The missing paths correspond to cloudy days. In the foreground, you see houses, trees and a fence. The bottom of the image shows reflected light from the windowsill, where the pinhole camera was placed.

Summer to winter, 2022

A different visualization of the first image

Christmas at Karlov

A few weeks over the Christmas break of 2022. The Nuselsky bridge is barely visible., leading to the Corinthia hotel at Vysehrad metro station. A few landmarks can be seen on the horizon, with Vyšehrad castle not visible. A trail of light is visible on the left -- a vandal tried to remove the camera with force, almost destroying the camera, yet he failed.

These curves can be calculated analytically

And they correspond to intersections of cones with a cylinder (the camera). The vertex of the cone is given by the pinhole aperture. The axis of the cone is parallel to the Earth's axis of rotation. The vertex angle of the cone is 90° - the declination of the Sun.