Lens Mount Types

Are pentax 'm' mounts and screw mounts the same as the "k mount"? I am
constantly confused as to the matter, because I keep seeing 'm' mounts
that /look/ like they are the same as the k mount.

Also, do zoom lenses require power? I'd think no, no?

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Are pentax 'm' mounts and screw mounts the same as the "k mount"? I am
constantly confused as to the matter, because I keep seeing 'm' mounts
that /look/ like they are the same as the k mount.

Also, do zoom lenses require power? I'd think no, no?


You are confusing the LENS MOUNT TYPE (either screw mount or K mount) with
the LENS TYPE.

Here is a brief rundown:

Pentax had two major types of lens mounts, the screw mount, also known as
the M42, pr Pentax/Practica mount, and the bayonet-type "K-Mount" that
replaced the screw mount in 1975.

The timeline goes something like this:

1952: Takumar Lens. Screw mount.

1958: Auto-Takumar Lens. Semi-automatic. Screw mount.

1963: Super-Takumar Lens. Fully automatic diaphragm. Screw mount.

1971 Super-Multi-Coated-Takumar. First introduced with the Spotmatic II and
IIa camera bodies. Same as the Super-Takumar lenses, but with multicoating
to reduce flare. Also had special coupling for full aperture metering. The
Spotmatic II/IIa did not support this feature, but the ES, which was
introduced later in 1971, did. The Spotmatic-F, which was introduced in
1973 and the ES-II, also introduced in 1973 also supported full aperture
metering.

1971: SMC Takumar Lens. Introduced with the ES body, and later was standard
on the Spotmatic-F and the ES-II bodies. These were the same as the
Super-Multi-Coated Takumar line, but with the introduction of rubberized
focusing rings in place of the older knurled metal rings.

1975 saw the introduction of the K-Mount lenses and all screwmount
production of lenses and camera bodies ended, although the lenses and some
of the bodies were available as "new old stock" for several years
afterwards.

Pentax introduced an adapter that enabled the older M42 screw mount lenses
to be mounted onto the newer K-mount bodies. Lenses mounted with the
adapter could be used only in full manual mode, but this adapter provided a
bridge for photographers that had an investment in the screw mount lenses to
be able to continue using them on the K-mount bodies. (THE K-MOUNT LENSES
COULD NOT BE MOUNTED ON SCREW-MOUNT BODIES)

1975: The first K-mount lenses were designated "SMC Pentax" (as opposed to
the older line of "SMC Takumar" lenses). They are referred to as "K"
lenses, and they were essentially the previous generation of SMC Takumars,
with the new K-mount instead of the screw mount. The first camera bodies
that could use those lenses were the K-1000, the KM and the KX.

1977: Pentax came out with more compact bodies (to compete with the Olympus
OM system as I recall) and they introduced a new line of matching compact
lenses, which were designated "SMC Pentax-M"

1983 Pentax introduced a line of lenses that could be used in program mode,
called "SMC Pentax-A"

1987: F lenses were introduced. These had autofocusing capabilities, in
addition to automatic aperture setting of the "A" series.

1991: The FA Lenses came out. This is the current line of Pentax
autofocusing lenses. Three of them are labeled "FA-Limited" and are of
top-shelf optical quality, with prices to match.

In summary: The M42 Screw mount lenses were manual lenses. The F, FA and
FA-Limited lenses are fully automatic.

"Jeremy" on 04 Mar 2005 posted

So basically then when i see a pens for a pentax camera, its either a k or
a screw mount (with the screws being much rarer) and its unlikely to
confuse the two mounts, whereas there is a variety of types, like pentax-a,
pentax-m, etc etc. Thanks for clearing that up.