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modification for lens of different focal length
This seems like a good time to display a way to modify the focusing linkage for those who want to use a replacement lens of a different focal length than the original one. The camera on the left has the bellows extension linkage in the original configuration. The camera on the right has been modified for use with a lens of a shorter focal length. Both cameras are set to infinity. Modifications to the camera on the right: The lensboard was removed from the struts and material was removed from the top to allow mounting of a better lens and shutter. A pc flash connector was also added to the lensboard at this time and later electrically connected the the flash contacts of the shutter. The new lens had a focal length of 90mm as opposed to 114mm. With the orginal set up, the bellows would not retract enough to focus at infinity with the new lens. The struts were shortened by removing material at the outboard end. The pivot point was also changed on the lens board. I temporarily installed a groundglass at the film plane and the lens was focused at infinity with the struts diconnected from the lensboard. New holes were drilled in the lensboard and modified strut ends, to retain the assembly at this position. The focus scale was then recalibrated for this modified linkage. A viewfinder off a Polaroid J66 was installed and oriented to match the groundglass image.
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Last edited by 2maneekameras : 06-06-2006 at 07:17.
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