The Asahi Pentax 6×7 remained essentially unchanged for twenty years until 1989 when Pentax finally released the first significant upgrade in the form of the Pentax 67. But if you didn’t know it, one would be hard pressed to identify the differences other than the name change. Karen Nakamura gives the best explanation of the new features of the 67 at Photoethnography.com’s Classic Camera DB.
“In 1989, the Pentax 6×7 underwent some other upgrades, most significantly the shutter timing was changed from being partly mechanically to being fully electromechanically controlled. This helped improve exposure accuracy (unfortunately it also meant that the bulb-mode required batteries, which disappointed many astrophotographers; you can get Pentax to modify your camera to not require batteries in bulb). Some components of the all-metax 6×7 were replaced with polycarbonate to lighten it. The upgraded model was renamed the Pentax 67.”
If you get the accompanying prism viewfinder, it only says “Pentax” where as the 6×7 one said “Asahi Pentax”.
After enjoying the 6×7 for a couple years I found the 67 for about the same price as the 6×7. It didn’t have a lens but came with a very clean copy of the TTL viewfinder.
On June 22, 2012 I sold the older 6×7 along with a couple of TTL finders and a prism finder along with several other cameras in order to finance the purchase of a lens for my Mamiya 6. But I kept the newer 67 and kept the most accurate of the three TTL finders, even though the exterior is the most worn of the three.
Here are some photos taken with these cameras.
The original line of lenses for this camera are labeled “Super-Multi-Coated Takumar” and have all metal focus rings and grips. The later SMC Pentax lenses have rubber grips on the rings.