Lenses and different mounts

Hi all - I have recently bought a K10D and I am very confused regarding some of the old lense's available.
I have seen - M42, M, K, KA, Screw, PK, PKA etc.
Can anyone tell me what types of mount will fit directly onto the K10 and which will fit with an adaptor and if there will be any functionality problems.

Richard

M42 and screw are the same. The others are all Pentax 35mm bayonet mount, otherwise known as K-mount, and they will also fit the various Pentax DSLRs.

M and K (aka PK) are early lenses which are incapable of having their aperture set by the camera body. They only work in manual exposure mode.

KA and PKA refers to lenses with an A setting on the aperture ring, which means that the body can set the aperture. They provide full exposure automation, if required, or anything in between that the body can handle.

The KA lenses carry the following suffices after the words SMC Pentax:

-A (manual focus)
-F (auto-focus)
-FA (auto-focus)
-FAJ (auto-focus, no aperture ring)
-D FA (auto-focus, optimised for digital, but OK for film)
-DA (auto-focus, digital only)

The screw mount lenses require an adapter to fit K-mount camera bodies, and require manual exposure setting.

G

Richard,
It's been covered here many times before...

In general terms, "PK" = "K" = Pentax bayonet mount. And "screw" = "M42".

You can mount M42 screw thread lenses with an adapter - but you have to do stop down metering by hand. That is, you open the aperture to focus, then manually wind down the aperture to the required setting before taking the shot.

K-mount lenses will all fit (however, I strongly suggest you avoid the Ricoh ones as these have an extra pin that can get stuck on the body :shock.
If the lens has an "A" on the aperture (sometimes referred to as KA or PKA) then the metering will work just fine on the K10D. In Pentax lenses, these are the "A" series, e.g. SMC-A 50mm/f1.4

If the lens is an older manual aperture K mount lens, then you have to use stop-down metering. There's currently an issue with doing this - the K10D offers a level of automatic metering that doesn't seem to work very well. You can meter wide open and work it out, but that's a real pain! Hopefully it can be answered or resolved a bit later... These are referred to as "M" series lenses. e.g. SMC-M 50mm/f1.2

Finally, there are the autofocus lenses:
* SMC-F series will work on all Pentax bodies, film and digital.
* SMC-FA series are the updated SMC-F. Some lenses are optically the same, but have a wider manual focus ring (when you want to manually focus).
* SMC-DA are for digital only and work on all Pentax DSLRs
* SMC-DFA are for film and digital, but optimised for DSLRs

Hope I haven't missed any!!
Matt

Thanks chaps - that has cleared up the mystery for me.

Richard

Thanks thats helped me out as well.