My digital photo archive spans 15 years and holds about 12,600 pictures (not so many, after all). I’m curious to see if there is a correlation between the exposure time of my photographs and the time of the day they were taken. A rather simplistic observation, perhaps.
In short: there’s nothing spectacular about this correlation, but it’s nice. The morning hours are the ones with the lowest average exposure time at around 1/320 s between 9 and 10 AM . There’s a sharp increase between 12 and 1 PM, then it increases again after 4 PM towards dusk. I don’t take many pictures at night!
See for yourself.
The most frequent values for exposure time are in the table below. 1/30 s is the typical exposure time when using the flash, and it’s recognisable in the plot above.
| 1/n s | occurrences |
|---|---|
| 800 | 1986 |
| 1000 | 1178 |
| 30 | 943 |
| 400 | 547 |
| 250 | 488 |
| 640 | 458 |
| 200 | 450 |
| 500 | 388 |
| 320 | 342 |
| 160 | 337 |
The Python and R scripts are at Codeberg https://codeberg.org/steko/expotime but were originally at Gitlab.com (giving GitLab a spin since GitHub is a monopoly and I don’t like that). I’m still doing some experiments with the source data, then I’ll upload those as well.