Went from guessing on shutter speeds with a phone app to an actual tester, and I feel dumb for waiting
For the first couple years I checked leaf shutters by ear and by firing them at 1/125 and calling it close enough, which worked until a guy brought in a Rolleiflex from the 50s that was shooting a full stop slow at every speed and I had no way to prove it. I picked up a cheap shutter tester off eBay back in March, and suddenly I could see exactly where the curtains drag on an old Nikon F instead of just telling customers it 'feels a little off.' Curious what you all use for the really odd stuff, since mine struggles with anything below 1 second.