Originally posted by dh4412 bigdave: i thought, that when using manual focusing , only the center metering is actually working? does the spot , really narrow the metering point down , then ?
There are two different concepts here, metering and focus. For metering, any lens with an A setting can use multi-segment metering, 77 segments on the K-7 or K-5, 16 segments on everything else. If the aperture displays in the viewfinder, that lens has the A setting. With older lenses that don't have an A setting on the aperture ring, the camera automatically chooses center-weighted metering instead, even if it's set to multi-segment. For any lens type, you can choose spot-metering instead, and the meter will only use the very center of the frame. That's kind of a specialized metering, so be sure you know how it works before using it.
Focus has different rules. With an autofocus lens, the camera can use different focus points, I think it's anywhere from 5 to 11 points depending on the model. Some points are cross-type and some are not. With a manual focus lens, only the center point is active. The other points are switched off automatically. With an AF lens you can choose to only use the center point also, but you get no choice with an MF lens.
It may be useful if you have a lot of different lens types to set center-weighted metering and a single focus point, so the camera operates one way all the time.