Originally posted by Bjun
Thank you. But I know that p6x7 and p67 finder are compatible.
I saw several photos of P67 ttl pentaprim finder on body of P6x7.
I don't understand that it's only available for P67-ii.
Are you sure what you're saying? I'm confused.
Gary Wakeling is correct.
You can freely substitute TTL meter prisms between the older (1969-era) and newer (1989-1990-era) cameras, that being the Pentax 6x7 and other variants (1969) and the Pentax 67 (the later model).
But--
You cannot use the TTL meter prism intended for the Pentax 67ii on the older Pentax 6x7 / 67 bodies. Why? Apart from the electronics and design, the 67ii meter prism has a lot of metering and switching systems that are entirely absent in the original Pentax 6x7 / 67 cameras.
---------- Post added 2nd Apr 2019 at 06:07 PM ----------
Originally posted by Bjun
I finally understood what you were saying.
My question is whether the Pentax ttl finder(not the 'P67ii' ttl finder you linked to me) has better performance than the Old Asahi-Pentax ttl finder .
Well, that clears up one point.
The finder you mentioned, the very old Asahi-Pentax (and older Honeywell), is frequently implicated with derangement or intermittent/poor (erroneous) performance as a consequence of age (do the math: how many years ago did these things come out?). A much better option is to look specifically for the newer Pentax 67 (not 6x7) finder, preferably in very good to excellent condition -- research carefully. The better the condition of the prism, the higher the price you should expect to pay.
There will not be an increase in viewfinder brightness. If you want that, use a waist-level finder or a chimney finder with adjustable diotric corrrection; both of these options will also provide 100% coverage of the viewfinder, while the TTL prisms (metered or not) provide only 90% coverage.
Separate (handheld) metering
The TTL meter prism on the Pentax 6x7 and 67 cameras meters down to 1 second over a 5-stop range. There will be times, no doubt, when your scene dictates an exposure longer than this, hence
the need to tool up with a hand-held meter to take over where the camera left off. A hand-held meter will also be required if using a chimney- or waist-level finder in place of the TTL metering prism.