RB67 90mm K/L Lens: Floating Elements and Spacing Adjustment
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Mamiya RB67 90mm K/L lens repair and info. First, some information on these lenses regarding a question that I am frequently asked: All the Mamiya RB67 90mm K/L lenses have floating elements although not all of them are marked as such. Starting in February 1993 (date code MB), Mamiya began marking the side of the lens “Floating System”. No change in the lens design, just different markings added. Shown in the first photo are two copies of this lens, one from August of 1991 and the other from March of 1993 with the markings.
The particular lens that I am servicing had some issue with a lens element that needed replacing. Also, the lens had a previous repair attempt that left it in less than ideal condition. Adjusting the floating lens elements takes special tools shown in photo two. Photos three and four show the actual spacing adjustment being made.
