Originally posted by Eruditass No matter the aperture, no matter the light coming in (which is effectively the same as changing the aperture since the body doesn't know the aperture).
I'm hoping this is a K-x bug and assume that all other Pentax's actually try to get a shutter speed based on the FL.
In addition, I noticed in M mode it doesn't meter the scene unless I assign the green button to optical preview and hold it down. Is this normal behavior as well?
All this is normal behaviour, not a bug. When using manual lenses on my K200D or K-x, in M mode, the camera only meters/calculates an exposure once the green button has been pressed. See the K-x manual at page 284: 'Notes on [22. Using Aperture Ring].
The way I use my M lenses is:
- I always set the mode dial to M,
- then compose the shot,
- set the aperture (or stick with a handy default),
- focus,
- press the Green button to get the camera to calculate the appropriate shutter speed (by stopping down to the indicated aperture), then
- press the shutter.
Works pretty reliably.
I have the Green button action in Manual mode set to Tv SHIFT [Menu 4 > Green Button > Action in M Mode > Tv SHIFT].
I think the default may be P LINE, but when using M series lenses the camera forces Tv SHIFT on you anyhow, since in M mode using M lenses there's no other real option other than to have the camera adjust the shutter speed, since it can't dynamically read or adjust the aperture like it can with A and newer lenses.