Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram (astrodon.social)

Article summary

The article discusses a project that combines 15-second interval whole-sky-camera photos to form a 4-year spanning keogram, which is a visual representation of the sky conditions over time. The keogram is created by taking a central line through each image and stitching them together. The resulting image shows the movement of the sun, moon, and stars over the 4-year period. The project uses an astro camera and a Raspberry Pi to capture the images.

Main themes

• Keogram creation
• Astrophotography
• Image processing
• Sky conditions
• Time-lapse photography
• Historical astronomy

What commenters say

• The keogram is a useful tool for quickly identifying interesting sky conditions, such as clouds, aurora, or other activity, but it discards a lot of information from the original images.
• The project's use of automatic exposure settings may limit its ability to accurately capture the gradual brightening at dawn or degrees of darkness at night.
• Locking exposure, aperture, and white balance settings could improve the accuracy of the keogram, but it may be challenging to achieve sufficient sensitivity at night.
• The keogram's centering at 4:00 rather than midnight is arbitrary and may be done to highlight the interesting variation in the night sky.
• The project's use of a fixed camera view and astro camera allows for a unique perspective on the movement of the sun, moon, and stars over time.
• The keogram can be used to validate computer-generated charts of daylight hours and can provide a interesting visual representation of the equation of time.
• Historically, people did not spend all their time looking at the sky due to boredom, but rather had various forms of entertainment and activities, and the keogram is a modern tool that can help us understand and appreciate the sky in a new way.
• The project's technical details, such as the capturing rig and image assembly process, are of interest to some commenters and could be explored further in a technical write-up.