Pentax 67 Pentaprism vs TTL prism & S-M-C Takumar vs SMC Pentax lenses

[jett]

1) What is the difference between the non-metered and metered prisms? To my surprise the TTL prisms are the same price as the pentaprism. Is the weight, magnification & coverage the same?

2) What is the difference between the two metered prisms? The description on keh.com says that one has an on/off switch while the other is "single-position". What does single-position mean.

3) According to this website, http://www.antiquecameras.net/pentax6x7lenses.html, there were three 105/2.4 lenses. I was thinking of getting the second one because it is cheaper. Anyone observe any differences between the last two?

[Nettar]

jett, it's been a long time since I used my 6x7, but I bought it with the standard prism in the early 1970s, and got the metered prism not long afterwards. I didn't notice any change at all in the image I saw in the viewfinder -- just a big improvement in ease of use. At the time, unmetered prisms were available very cheaply, since everyone was exchanging theirs for the metered variety.

In the period during which I used the camera, from 1973 to about 1995, I had two or three different 105mm lenses, the last purchased in about 1990. They looked a little different but, to my eyes, had exactly the same optical performance. I guess that, optically speaking, only the coating changed. Nettar

[Frontman]

Originally Posted by jett

1) What is the difference between the non-metered and metered prisms? To my surprise the TTL prisms are the same price as the pentaprism. Is the weight, magnification & coverage the same?

2) What is the difference between the two metered prisms? The description on keh.com says that one has an on/off switch while the other is "single-position". What does single-position mean.

3) According to this website, http://www.antiquecameras.net/pentax6x7lenses.html, there were three 105/2.4 lenses. I was thinking of getting the second one because it is cheaper. Anyone observe any differences between the last two?

There are a few variatons of the TTL meter. The switch on the earlier prisms had two positions, on and off. The later prisms have a one position switch, you push the switch to activate the prism, and then release it, and the meter powers off automatically after a few moments.