The Pen-FT, introduced in 1966, advances this to a single stroke film advance, a built-in self-timer, and open aperture TTL (through the lens) exposure metering, among others. The TTL metering uses a semi-silvered mirror which splits a portion of the incoming light to the metering cell, and the rest to the viewfinder. This result is a viewfinder that was, unfortunately, dimmer than that of the original Pen F.
Oly35mm Review - Olympus Pen FT
The Half-Frame Film Format
When an image is framed and focused, the TTL meter pointer, displayed on a vertical bar on the left when looking through the viewfinder, will move up or down the numbers from 0 to 7, the optimum exposure recommended for the scene. This number is then manually transferred to the aperture setting of the lens, by aligning this number it to the white dot marked on the body of the lens barrel.
Olympus Pen F FT FV
Using the Camera
The Holy Trinity of Half Frames | Olympus Pen F Review | Part I Review: Olympus Pen FT