Originally posted by Darrell Raw Can anyone help me with the lens? It's a Vivitar 90mm 1:2.5 MC Macro Telephoto Serial no. 28500669. I can't find any reviews on it, there's a Vivitar 2.5 that's 1:2 macro and a 2.8 that's 1:1, however this is a 2.5 AND 1:1 without adapter. It seems sharp enough, in fact sharper than the takumar 100mm f4 and Pentax-m 50mm macros I have. Serials starting with 28 are supposedly Komine manufactured, but again I can't find a matching f2.5 with true 1:1 macro. It's as if this lens doesn't exist, yet it's sitting on my camera now.
maybe post a picture of the lens...? A lot of these lenses were manufactured by different companies, somebody here could recognize it.
Edit: as I suspected when writing the above, I remembered reading something about this as being a different brand, but the same lens as the panagor 90mm pmc macro f/2.8. It might say 2.5 but.. effectively probably it´s all the same. If I´m right your lens should look almost the same as the panagor.
Here is the review, scroll down considerably and you´ll find a comment with lots of info... the last comment made. I don´t know the person but seems reliable:
https://www.pentaxforums.com/userreviews/panagor-90mm-f2-8-macro-pmc.html