It took me quite a long time to find out how to make the dry fire of my Pentax 6x7, i.e. to fire the camera without film inside. So this post aims to be the best guide ever to make the dry fire .
1) Use a battery eliminator or assure that a battery is inside.
2) Open the camera back as much as possible.
3) Turn the small wheel in the center of frame counter with your finger so that the counter shows a number between 1 and 10. When turning the wheel, you must press it evenly, i.e. not to touch it only at one point.
4) Close the camera door while still holding the counter dial wheel.
5) Cokc the winding lever. If you use a battery eliminator, push the safety button with it now.
6) The camera is now ready for the dry fire!
7) When the shutter is open, you can open the camera door and look inside!
When I found how to make the dry fire, I learned within a few hours about my camera as much as in the previous four years that I have it. For example, I sometimes encountered the problem with mirror hangign at half way up. Now I found that this problem can have two reasons: I either accidentally pressed the MLU button when the battery was not inside, or I pressed the shutter when the battery was not inside and the safety button was not fully pressed by the battery eliminator. When the mirror hangs in the half way, it is enough to press the safety button to allow the mirror to go up.
Next, I found that the interior of the camera is blackened completely insufficiently (joking - partly). When you look against the light with your eye near the plane of a wall of the camera chamber, the wall is quite bright. So I made the dry fire, opened the camera's door and pasted pieces of black velour wallpaper inside. One of them hangs on the mirror at the non-reflective side. The camera is sufficiently overdimensioned so that it has no problems to lift the mirror up. I used this wallpaper to blacken the inside of my telescope, too. I hope this will help to reduce the faint light stripes that I used to have along the sides of my photos.
And here is the overall view on my camera at its current stage. My improvements: homemade vacuum back, battery eliminator, blackened interior of the camera and MLU button taped up to prevent accidental pressing.
Edited by Michal1, 22 September 2014 - 03:25 PM.