I'm more into keeping track of lights around town then I am collecting them. Especially HID.

I keep track of when they get relamped, fail, start day burning, start cycling, and I time how long the cycles are on a given date.

There is a tunnel I walk through and about once a month I'll count how many lights are on as I walk through it. If a lamp is cycling, it only gets counted if it happens to be on when I walk under it.

I'm on there how about changes over time. I take lots of walks outside so maybe it's just something I do.

There is a warehouse by my house that has lots of HPS flood lights, and maintenance comes by about once a year to replace all the lamps that are cycling. I tried to guess which lamps are going to fail in the following year based on the color and timing at startup.