Originally posted by wasser I don't follow. How can you have a manually set aperture but a body that ignores it? The body has no choice! Am I missing something again? Perhaps it's different lenses.
To clarify, my lenses are M42 Takumars.
Ah, that's different. I thought we were talking about K-mount lenses. With K-mont lenses, the aperture stays fully open as you turn the aperture ring (to make focusing easier). The camera moves a switch on the lens mount when it takes the picture in M mode in order to stop it down. The lens stops down to the selected aperture just long for the picture to be taken, then springs back open. The camera also stops down the lens when pressing the "meter" button or when doing a DOF preview.
In Av mdoe, however, the camera never moves the switch to stop down the lens. Not when you press the "meter" button, not when you do a DOF preview, and not when the picture is taken. So the lens remains fully open.
Quote: The aperture rings have no "A" position, but there is a switch for "manual" and "auto". I just have to be sure I'm in "manual" when I meter and shoot. Of course, "auto" leaves it stuck wide open.
Right - and K-mount lenses are like the M42 lenses that are in "auto" all the time in that respect. Except that I'm not sure if any Pentax DSLR is capable of stopping down an M42 lens that is in "auto", but it definitely can for K-mount lenses if you are in M mode.
BTW, I keep mention DOF preview - that's something the K2000 doesn't have. On other Pentax DSLR's, it a switch you turn that causes the camera to stop down to the selected aperture for as long as you hold the switch. The original purpose was to let you check the DOF in the viewfinder. With manual K-mount lenses, though, it's also the only way to get a meter reading to display. When you use the "meter" button in M mode, it stops the lens down only momentarily, takes a meter reading, and sets a shutter speed to make the meter read 0.0, but then the lens opens up and the meter display turns off again.