Originally posted by Colbyt Just about everyone here knows more than me but I can answer at least one of your questions. Any Pentax A also know as KA will work on any Pentax DSLR and stop up or down for the aperture leaving you to only deal with the manual focus.
The Pentax M lenses can be used on most models in full manual mode. That is not true for the k2000. The same is true for the older screw mounts.
BTW, welcome aboard.
Originally posted by Colbyt You can use them. They shoot wide open in any mode mode other than full manual.. There is no way to set the f/stop for any of the program modes. This is one time I would love for you or anyone to prove me wrong and tell me how to do it. Please!
Well now...do they or don't they?
The k2000/Km is no special exception. I'm not sure what you mean by, "program modes", but, whether you use the K-r, Km, k5 or what have you, M and M42 lenses have the same functionality on each:
M lenses are limited to manual mode.
M42 lenses may be used in either M or Av*
.
No matter what Pentax camera you have you can't make either the M or the M42 function in any other mode. Other modes require the
camera to adjust the aperture of the lens. This can't happen on a manually set aperture.
*To get M42 lenses to work properly on my Km I have to either short the bottom most pin (a bit of foil works), or I have to adjust the exposure compensation to Ev +2.
[edit]I forgot to add that on the M42 lenses you'll either have to be sure the lens is set to Manual mode, or the pin that stops the lens down is jammed. No digital body can slap the pin to stop it down.