Konica Minolta TC-X - Manual (Page 13)

Microdiaprism Split image Matted plane
Focus at the center of the viewfinder
When focusing, point the camera directly at
the main subject (area of the picture that is
most important), to use the split image and
microdiaprism for precise focusing.
Split image: The lens is focused when the
upper and lower halves of the image in the
center of the finder are aligned.
Microdiaprism: When the lens is focused,
the image in this area of the finder stops
flickering.
Matted plane: Use the matted screen surrounding the center of the finder to focus whenever the image at the center is not