Bright field focusing
1 You can start viewing and focusing before and after cocking the rapid wind lever. When the automatic preview lever is in the "AUTO" (automatic) position, the meter is at "OFF", the diaphragm is fully open except for the moment of exposure.
2 Turn the distance scale ring until your subject image is clearly in focus. It is not always necessary for you to view and focus with the diaphragm fully open. In bright sunlight, you can easily focus with the diaphragm closed to f/5.6 or f/8 and still observe the depth of field. It is easier, however, to focus with the diaphragm fully open as your subject image is much brighter.
When the letters "MAN" appears beside the lever, the lens is in manual position; when "AUTO" appears, it is in the automatic position.
Microprism
Asahi Pentax cameras have a Fresnel lens with a microprism center underneath the ground glass. As you look through the finder, you will see that the Fresnel lens consists of many concentric rings which provide the brightest possible image on the ground glass.
The microprism is the center portion of this diagram. When your subject is in focus, the image in the microprism will be sharp and perfectly clear. If your subject is not in focus, the microprism will break the image up into many small dots, much like and engraver's screen. You can focus your subject on any portion of the ground glass.
Reproduced for Historical & Reference purposes by Paul M. Provencher - | 11 |
http://whitemetal.com |
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