How long can you leave a film in a camera?



Just wondering how long you can leave a part used film in a camera? I have some velvia that I have half used in my camera stored in a camera bag under the stairs but wonder if I shoulduse it up sooner rather than later or whether it will be ok?!?!
I just had some film developed from some of my Fathers old cameras and I reckon one of those films had been in there at least twenty years! There was a rather young looking me being driven round in a friends freshly finished beach buggy. It came out brilliantly although the young girl was a little frustrated when she tried printing as it was a half frame format camera and the computer was not at all happy trying to get prints out onto normal paper!
Well I suppose an exposed neg is the same in a film canister or camera, so I'll start the ball rolling with an exposed film found in a drawer and after developing was dated as 8 years had a slight colour cast but otherwise ok.
For ever, maybe "How long can you leave film in a camera and still develop it?" might have been better ;) I developed one that was more than 10 years old but I bet there are people on here with some stories :nuts:
I think I should be ok then - as long as I use it within the next 10-20 years! Shouldnt be too much of a problem!
I found a roll of XP1 (YES XP1 not XP2 Super!) in my Yashica last year - think the film had been in the camera a little over 20 years! The shots were okay, considering the camerabag had been in the loft, cooked in the summer and frozen in the winter. I'd say providing the under-stairs cupboard is not home to the gas central heating boiler, you'll be okay!
the problem starts when your camera with film inside gets scanned at the airport, there is a big chance it will get exposed it, if it's a sensitive film (1600/3200)
don't trust airport staff.
In the late 80s I picked up a 120 camera on a flea market that had B&W film inside. I processed the film and it was slightly fogged by light ingress through the red film counter window but perfectly printable. Judging by the cars in was mid 1950s when shot.

It's difficult to judge how long to develop such films and if you were picky you could process a clip from the end of the film, which is what I did.
depends on the film.
Velvia will go off quicker than just about any other film. You should get it developed before the film expiry date. It will develop if left longer but the colour will be off.
Now if it was black and white film you could leave it in there for 50 years and it would be fine. It may lose some contrast but you can compensate for that in printing.