First I tried to do this with a GoPro and it sucked. So I just stuck a spare iPhone up there and had it take 3 photos a day for 5 months using OSnap. It only took the photos during daytime hours to keep customers out of the shot. Unfortunately sometimes the lights were on and sometimes off, so it flickers like crazy. Also I only ended up with about 3 months worth of photos, because sometimes OSnap would crash at random, and sometimes iOS would decide to pop up an alert, and that made all photos stop until I clicked OK a couple of weeks later.
What have I learned? That our bar surface's unique fingerprint changes much more slowly than I expected. And that taking decent time-lapse video is really hard.
I had good luck with an old Canon Powershot and the CHDK development kit for a long term time lapse. Initial setup can be a bit tedious, but with an external power supply it just ticks on forever.
Seconding the CHDK recommendation; I've used it to generate timelapses from my rooftop, and would still be doing it if (a) I had a view worth a shit right now, or even (b) unalarmed roof access in my building, and mostly (c) I hadn't left the camera and power supply at work during the Isolation.
What happens at 0:06? Overzealous cleaning?
” What have I learned? That our bar surface's unique fingerprint changes much more slowly than I expected “
Years ago I worked on something I called The Interval Project. One of the goals was to find the right interval time appropriate for different activities and phenomena. I’d categorize your steel corrosion case under the “watching grass grow” category due to the slow pace. An interval of 6-24 hours is probably the best fit. That interval was well beyond the range of the film equipment I used which had a max interval of two minutes.
One shot per day would result in a video showing one month per second. An entire year could fuel a twelve second video clip. That’s a long wait!