Reading over the Pentax FAQ (well, one of them, I think I've found three or something -- btw, glad the pmdl FAQ link is restored), I read the K-1000 has mirror lock-up.
If you tap the shutter button gently. That's happened to me 5-7 times so far. Naturally when I was shooting wildlife or something where I felt it was crucial to take a pic THEN. Boy, that's a relief. I had begun to wonder if the camera needed repairing or something. But since it didn't ruin the film or anything I figured I'd just live with the "glitch" for now. Only -- hey, it's not a glitch, it's a feature! Doe :-) aka Marnie Parker Hehehehe.
