There is nothing such as “maximum shutter actuations.” People act as if there were some magic number. People freak out about this. The rated number is unlikely to be reached for most amateur photographers. It’s unlikely to be reached by two amateurs using a camera back to back. Maybe even three or four, unless one used the camera at the beach or somewhere gritty.
- The rating itself is the MTBF, or Mean Time Between Failures. That means that on average, Nikon’s rated shutters last 150,000 cycles. You don’t know whether that means most last to 250,000 and relatively few go 50,000 or whether all of them are somewhere around 150k.
- There is no warranty that a shutter will get to 150,000. Your two year factory warranty will expire one day, and it could be at 18,000 exposures or 180,000. Doesn’t matter. Nikon is not fixing it for you for free.
- Inside the factory warranty, Nikon does fix it for free, shutter count notwithstanding.
- Likewise, Nikon is not fixing your used camera, even its original sale was within 2 years ago, or even if the shutter failed at 8,000.
It’s all marketing.
By the way, when Nikon was coming up with its 150,000 exposure MTBF, that was 4,166 rolls of film, which was more than most people shot in their lifetime. For a pro, a new shutter (which in those days was a $250 repair) cost nothing compared to the cost $12,000 in film you shot before you got there!