Gear that is getting old has a tendency to develop random little quirks as stuff wears out a bit, or unexpected 'features' that can catch one off guard.
Plus, some bits of gear left the factory with more than a few interesting little quirks of their own...
So what interesting little quirks of your medium format film gear have you discovered over the last while?
For me, I found 'fun and exciting' issues with two pieces of TLR gear:
1. Rolleicord - Not 100% what exact year/model mine is, but I've found that the mechanism to lock the film advance till after you've fired the shutter is very inconsistent in unlocking... Which leads to the film advance knob randomly not wanting to turn after taking a photo at times. It will work fine for one roll of film, and lock up every single frame on the next.
Thankfully the work around is easy: Just press the shutter while starting to turn the knob, and let off as soon as the film starts advancing on its own.
2. A Mamiya TLR 250mm lens that I recently picked up has a fun quirk, in that it will work just fine with no issues if the flash switch is set to X, but will jam the shutter cocking lever just enough to keep its spring pressure from letting it travel all the way to release.
I had noticed that it wasn't firing cleanly when I first picked it up, but it worked fine after being tripped a few times, so I chalked it up to simply being a bit sticky from sitting on a shop shelf for awhile - My other lenses from that system will do similar, and then be fine with acceptable timing till they're left to sit again.
And apparently there isn't a lot of difference in sound between that lever travelling all the way and tripping the shutter, and it jamming just before it would release the shutter, when you're using the faster few speeds...
I have no idea when that switch got flipped back, so I may have a lot of interesting photos of the inside of my camera from the first week or so of owning it. I may also have to reconsider gluing that switch... The novelty of having an unglued Mamiya TLR lens apparently wore off rather quickly.