Pioneer, I dispute your quote: "First, a deteriorating mirror bumper will change your focus point."
Pioneer, the 'focus point' as it appears in the VF is determined solely by the height that the front edge of the mirror is at when resting on the (in the case of the K1000) wire bracket (front, right, just under mirror's front, right edge). The 'deteriorating mirror bumper' (the foam that the mirror hits when an exposure is being made) is necessary to soften the mirror's impact and also disallow light from possibly fogging the film during exposure. But it has NOTHING to do with matching the apparent focus (VF) with actual focus (film plane). Of course, a deteriorating foam can cause a mess and can cause the mirror to annoyingly remain at the top for a few seconds due to stickiness.
In fact, I have, in the past, recommended that one should test this matching of 'apparent' (VF) and 'actual' (film plane) focus so that one can shoot wide open without focus worries. Do this: WIDE OPEN WITH A NORMAL OR LONG LENS, shoot a 'picket fence' type of object, 45 degrees from the camera, and focus PRECISELY at a determined point. Then process the negative and place it into your enlarger. (NOTE: it helps to slightly underexpose the negative so that the image from the enlarger will be bright and clear). Then determine where the ACTUAL focus is. Rule of thumb: IF ACTUAL FOCUS IS IN FRONT OF THE APPARENT FOCUS, lower front of mirror very, very slightly. IF ACTUAL FOCUS IS IN BACK OF THE APPARENT FOCUS, raise front of mirror very, very slightly. On the K1000 a very slight pressure on the metal bracket will do the trick. Some cameras are a bit more sophisticated like the Fuji ST series and, amazingly, the Soviet Zenit (!): they both have a set screw that the front of the mirror rests upon so simply turning it with a screwdriver is all that is needed.
Love the K1000 but despise its lack of self-timer. Mistake by Pentax. - David Lyga.
Last edited by David Lyga; 07-18-2013 at 08:43 AM. Click to view previous post history.