Why is Nikon considered the standard?

I have been using Pentax camera's for almost 20 years now, with my latest being the *istD. However I get the impression that Nikon has become the Professional standard ... Why?

Did Pentax miss something when marketing in the 80's.

It goes back a lot further than that. In the Korean war supplies of the new (to the West) Nikon and Canon rangefinder cameras started to find their way into the hands of the press photographers of the day, and they were staggered at the (especially Nikon) lens quality. The Japanese lenses were very contrasty compared to the leica and Contax (Zeiss) lenses they copied, and very, very sharp. So the 1950s saw the upsurge in the Japanese rangefinder systems.

In 1959 Nikon made a second major coup by introducing this quality to the SLR - the Nikon F, with especially its superb 200mm lens. Nikon built upon this reputation by building robust camera bodies, frequently shown working after being dropped from helicopters and immersed in buckets of water! And superb lenses.

Nikon became the professional camera. Pentax made their coup in 1964 with the introduction of the Spotmatic and the first fish eye lens that could be used without locking up the mirror. The stuff os the swinging sixties, but with more of an advanced amateur appeal with some professional use.

Canon have taken a similar path to Nikon but by being always at the cutting edge of the next development. They have and do make professional cameras and lenses, although they have never appealed to me much.

Pentax have only tried one proper professional system, the LX. A superb camera, but doomed to commersial failure in the market dominated by the Nikon F series.

I prefer the operational features of the pentax cameras, but if I didn't use Pentax I would use Nikon.