[05]

> use a $200 camera and photograph your keyring from a couple blocks away

Rayleigh criterion: to resolve an angle of 4E-6 rad (key bitting step is 0.015inch =~0.4mm , two blocks is 2 * 200ft =~100m), you'd need a ~140mm aperture lens. Can you really buy one (with a camera no less) for $200?

[observationist]

Well, TIL I'm shitty at the private eye thing, lol. You'd need to get up close, then, or have really good cameras. You're not going to need .4mm precision so long as you can see the differential pattern, though. Memorizing a 5 digit number, each digit between 1-6, and you can remember any kwikset key at a glance, and so on. At most you'd need to print 10 possible solutions if you can't find an absolute difference between lowest and highest points, but most of the time the pattern will have 4-6 potential keys it could be.

Anyway, locks and keys are inconveniences that keep people from casually abusing civil boundaries, is the point, and not all reasons for overcoming those are nefarious.

[05]

Yeah, seeing how better and cheaper cameras are sold every day I thought that it might be plausible.. and then it apparently isn't.. yet. Maybe with a cheap telescope :)

A covert camera placed near the keyhole is probably a better solution anyway, because most people don't flash their keys when just walking on the street (maybe when unlocking a car, but with keyless that's becoming rare).

[deepspace]

Used lenses from 30 years ago plus a DSLR from 15 years ago plus a suitable adapter will do the job, and may be in the price range with a bit of bargain hunting.