Maybe the problem is, that the camera does only know how many bytes on the card are still unused.
But it cannot know - not even roughly, as this is highly settings dependend - how many bytes storing of the next (not yet taken) picture will need.
My K200D I set it to show the remaining shots in the VF, and, pressing the center button, also on the top display. But this number is calculated very conservatively and often seems to have no real relation to reality.
I think with at least one of my older Pentax P&S models, the camera just stopped working with a warning, when also the buffer was full. Some or most of these models had a buffer surviving switching off, which was good enough for at least 1 picture in the highest resolution and jpeg quality.
Last edited by RKKS08; 08-25-2015 at 11:07 AM.
Reason: Typing