vivitar 40mm 1:2.5 auto vmc

[kiwigaffa]

I've had this lens for a while, and have never seen anything about it online. I was wondering if anyone could shine some light on it for me?

Its a PK-mount pancake, with an 8 digit serial number starting with a 9, and ending with 447, which if I worked the decoder ring properly means Cosina manufactured it in the 47th week of '74 or '84.

Anyway, its an interesting lens, and one I've never seen or heard of since I bought it, so...




apologies for the iPhone photos

[Layer-cake]

[calvin83]

It is a re-branded Cosina Cosinon 40mm F2.5.
http://www.pentaxforums.com/userreviews/cosina-cosinon-40mm-f2-5-auto-mc.html

[TrueLoveOne]

First time i see one! Do you have any results yet?

[Pancolart]

Darn thin. Have you measured it perhaps?

[tao]

Also available as a Porst. Vivitar and Porst version share serial numbers, started with 993-996. Cosinon started with 78. They were Cosina's answer to Pentax-M 40/2.8. All 5/4 Unar design, I think.

Notably, other pancakes from the same era are Chinon 45/2.8 (also offered as Revuenon), Makinon 50/2.8 and Ricoh 45/2.8.

[kiwigaffa]

Thanks so much for the quick ID and links to more info!

Sorry, I have no results, but if this weekend is nice, I'll try and get out with it to see what it can do. I've been using my Hexanons mostly for the last few months, so it's time for a change.

I also have the Chinon 45/2.8, so maybe some comparison shots are in order.

Speaking of comparisons, I measured it and it is 20.8mm from mount face to filter ring. The Chinon is 23.5mm, the Industar 50/2 is ~19.9 and the Hexanon 40/18 is 27.9. It truly is a tiny lens.

[Pancolart]

Wide open on A7. No PP. This is a keeper for sure.

[TrueLoveOne]

Very nice indeed!