Asahi introduced the famous Pentax K-bayonet in 1975. The Asahi lettering on pentaprism faded away slowly from K-series (where it was written smaller than in screw mount cameras) to M-series (where Asahi was even smaller and no longer black laquered). With the introduction of the ME Super in January 1980, all cameras were just called Pentax.Soon after the introduction of the K-series, Honeywell went out the photographic business. The photographic division of Honeywell (or part of it) was bought by Asahi Opt. Co., thus becoming Pentax Corporation. Camera designations for US market often continued being different from international market for commercial reasons.

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