Is Nikon's proper pronunciation 'Nick-on' or 'Nike-on'?

I'm almost certain it's 'Nick-on'…

Nike-on

Nope.

It's Nye-Con (do not combine the K with the N. The Ni is pronounced as 1 syllable)

Nikon is a Japanese company and over there the pronunciation is Nick-on. Any native Japanese speaker is gonna pronounce it that way, as you can hear here:

http://en.wikipedia.org/...:Nikon.ogg

So that would be the "real" pronunciation.

Americans usually say Nike-on because it seems more natural to them, so it's pretty much Nike-on in America even in the commercials. In the UK people tend to say Nick-on. I live in Germany and most people here say Nick-on, too.

The actual pronunciation is nee-kon

"knee con"

Depends where you are.
In Japan: Nee-Kon (correct pronunciation)
America: Ni-Kon
In New Zealand: Nick-on