Hasselblad, jam?

[MattKing]

All my Mamiya medium format cameras have had shutter release locks.

The position of the shutter release on most of the models (front bottom right corner) makes it easy to inadvertently release (a cocked) shutter when one places the camera into a camera bag, so they do make some sense.

[film_man]

My Bronica SQB had a lock. It was essential given that the shutter button is very light touch so you can easily fire the shutter. As for my Hasselblad, never had a jam in 2 years and dozens of rolls though it.

[Sirius Glass]

One question: Is there no shutter button lock on a Hasselblad? That would easily avoid triggering it accidentally.

Just leave the darkslide in place, that will lock the shutter.

OR do not advance the film until you want to shoot again.

[Sirius Glass]

Jams are rare if one follows the instructions: JRTFM!

Sometimes a lens will uncock while off the camera; just turn the screw to recock it.