RB67/RZ67 Lenses: Missing Rear Elements on Online Purchases
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
If you are buying RB67 or RZ67 lenses, please check them out very carefully for haze,fungus,separation. Especially the three lenses mentioned and shown in this post: RZ 110mm f/2.8 , RZ/RB 127mm f/3.5 and RZ 50mm f/4.5. While any and all lenses for these systems can show glass issues, these three seem to be the most likely to show up with problems in the rear cemented groups.
The three lenses pictured here were all purchased by me online (ebay). All of them showed clear glass. Well, probably a little too clear as these all had the offending separated element groups removed! Yes, unscrupulous people who think they are very clever have been known to remove the bad glass and now the lens looks fine. Except for the minor detail that the lens will not focus at all. So, it is important to also check focus even if the lens passes the flashlight test and looks good.
In all fairness, the seller said of the 50mm RZ lens that it might have the wrong rear element group installed. Wonder how the seller knew this? In this case, the rear element was missing a doublet. Photo two shows the rear element group with an emplty spot where the element should be living.
This is just a note to carefully check any Mamiya purchases very carefully as all of these cameras and lenses are now. typically 30-50 years old and may have passed through many hands. Some of these hands will try to deceive you .
