Summary of the K-Mount Evolution, Names, and Features

The following abbreviations are used throughout this page:

• M — manual operating mode, Av — aperture-priority, Tv — shutter-priority, P — program operation; Pg — “green” or “auto” program, smart-picture mode
• F — full-frame metering, C — center-weighted, S — spot; Mx — matrix.
• AF₁ — first-generation (AF-motor in lens) auto-focus capability
• AF₂ — second-generation (AF-motor in body) auto-focus capability
• D₁ — basic lens-body digital transmission: lens focal length, distance to subject, selected f-stop, lens physical size (for calculating whether the lens will interfere with the built-in flash), possibly other information.
• D₂ — advanced lens-body digital transmission: MTF, focal length at which the lens has its minimal length, possibly other information.
• PZ — power-zoom capability

Figure 1 shows the K-mount “family tree.” Each knot describes a mount variation, when it was introduced and what its name is. A branch running from variation A down to variation B indicates that B is based on A. The features that B has in addition to A are listed in blue; the features that B lacks in comparison to A are listed in red.

Figure 1. Family tree of the K-mount.

The K-mount has been in existence since 1975, and has gone through a number of revisions since then. There exist a large number of bodies and lenses with different names and features, and it is somewhat of a challenge to keep all the nomenclature straight. Table 1 groups each mount variation with the bodies and lenses that are based on it.

The K-mount has much to boast in terms of compatibility — if we exclude the bodies and lenses featuring the K_F and the “crippled” K_AF mount, combining any body with any lens produces a correctly-operating combo that possesses all features common to both pieces of equipment. Bodies and lenses featuring the K_F mount are fully-compatible with each-other as are the bodies and lenses featuring the “crippled” K_AF mount.

Table 2 lists all body-mount variations vertically and all lens-mount variations horizontally. Each cell enumerates all features that are possible when combining the respective mount variations. Note that not all bodies and all lenses implement every possible feature. Furthermore, there are features that are possible, yet no piece of equipment implements them. Such features are marked in red.

ⁱ = The lens stays set to its smallest aperture (f/32 or f/38), so the combination is, in effect, unusable.
ⁱⁱ = Severe limitations. Read the full story.
ⁱⁱⁱ = Some limitations. Read the full story.