Olympus SLRs in the half frame format began with the Pen F in 1963 and included the Pen FT that first came out in 1967 and the Pen FV of 1969. A good rundown of these models can be found at:
http://www.f22.org.uk/Galleries/Pen_Col ... r_pen.html
and an interesting account by Louis Meluso of using them at:
Though these Pens have a wide range of accessories to suit special needs, for me the appeal of the FT (the model I have) is (1) that it accepts interchangeable lenses and (2) that it allows precise focus through the lens all the way down to ~14 inches on the standard 38mm lens. The only competitor in capability is the Yashica Samurai line that came along twenty-five years after the first Pen F and the Sams use zooms rather than interchangeable lenses. By the way, there is persistent criticism of the dark screen on the Pen FT (because of diverting some light to the meter); I haven’t found that to be a problem because the image moves in or out of focus quite clearly and there is a very good micro prism spot in the center. I only have two Pen lenses-- 38mm f/1.8 and 50-90mm f/3.5; I do have the screw mount adapter and have successfully used Pentax lenses (which I no longer have) for special purposes. I think the best way to summarize my experience with the Pen FT is to post some photos.
All of my Pen FT equipment was bought used--the camera and 2 lenses came from a dealer in Minneapolis, about 15 years ago; he said that he got it from an outfit that made directories for church congregations. I mention this to suggest that at least for this one the build is pretty good-- maybe it was all the use it got taking the church photos rather than sitting in a drawer.
EDIT: The last photo was lost when the Imaizer server got into trouble. I wasn't able to put it back where it had been so I have placed it here.
Sculptured Female Head at Commerce Bldg. (?) St. Paul, MN
50-90mm zoom on Kodak Elitechrome