Two M42 Vivitar Fifty's need help

RioRico · Posted: Thu Dec 02, 2010 8:49 pm Post subject: Two M42 Vivitar Fifty's need help

Just arrived: two Vivitar Fifty's (and sorry, I can't provide pictures right now, maybe later) that seem to have come from the same lens foundry, judging by the fonts. They are:

Vivitar 55mm f/2.8 Auto # 94300958 (with strange A/M switching)
Vivitar 50mm f/1.8 Auto # 98102590 (with standard A/M switch)

The 55/2.8 has no A/M switch, but the aperture ring goes two ways, with 2.8 in the middle -- to the left it is marked AUTO 22-11-5.6, to the right it is marked 5.6-11-22 MANUAL. Kinky. The problem is that the M42 mount section, upon which that aperture ring resides, is rather loose. It is tightest near the AUTO 22 area, but opposite that (maybe 1/4 counter-clockwise from the aperture pin) the mount has in-and-out play of 2-3mm. Nothing fatal, just annoying, and not good for resale value!

The 50/1.8 has a standard A/M switch, and it seems to work, and the aperture pin seems to work, but the iris is stuck wide open. One of the 5 blades seems visibly out of place, slightly lapping over its neighbor. I had a similar situation with a Pentacon (Meyer) 50/1.8 -- I was able to just unscrew the mount and gently nudge the blade back into place -- SUCCESS! But this Vivitar doesn't want to unscrew so easily.

Has anyone any suggestions on how to get into these lenses for a fix?

aliasant · Joined: 17 Feb 2010 Posts: 39 Location: Stockholm, Sweden

I have a 55mm 2.8 (Komine) but it has the A/M Switch and looks normal ( Excellent lens btw). It sounds to me like someone maybe changed the aparture ring? Maybe replaced a broken one or modifyed it for some reason...
Post a pic of your lens maybe?

blende8 · Joined: 29 Sep 2007 Posts: 260 Location: Bremen, Germany

Here's an image:
Interesting. Never seen anything like that.

http://cgi.ebay.de/VIVITAR-AUTO-55MM-2-8-LENS-M42-SCREW-MOUNT-CLEAN-/390226162591?pt=Camera_Lenses&hash=item5adb4ab39f

aliasant · Joined: 17 Feb 2010 Posts: 39 Location: Stockholm, Sweden

Just realised I have the Macro lens and its quite different Embarassed

Looking at your weirdo I see that there are no obvious ways to unscrew the m42 mount so the screws that seems to be loose must be hidden somewere unless you can screw the mount of but that is probably not the case.

Have you tried remove the rubber ring and looked for hidden screws?

Another way might be if the aparture ring can be screwed off and then slided over the mount so that it comes off the lens? That might then reveal the loose screws?

mo · Expire: 2016-07-30

martyn_bannister · Joined: 23 May 2010 Posts: 1151

YMMV but if there is no obvious way in from the rear, I always try giving the front portion of the lens (NOT the focusing barrel) a healthy twist to see if it will unscrew. These things are almost always designed to come apart without disturbing the optics.

My 2p. Don't hold me to it Smile

RioRico · Posted: Tue Dec 07, 2010 10:26 am Post subject:

At last, pictures. I've been so damn busy with other stuff... First, the Vivitar 50/1.8 with the misplaced iris leaf visible at the (A) pointers:

I see some tiny grub screws in the lens body: one near the front, three under the aperture ring (accessible via cut-outs in that ring) and three behind the aperture ring. I am very nervous about touching them, and they are too small for my current screwdrivers. If they are the keys to opening this lens, I am screwed.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Now, the Vivitar 55/2.8 with the strange AUTO/MANUAL mechanism. Those don't seem to be grub screws on the bottom:

I unscrewed the focusing helicoid (because I could) and inside I found this:

A, B: in the front section, two screw-posts that must be focus stops
C: a loose screw-post of the same sort as (A and B)
D: a loose small screw that fits into holes (E or F or H)
E, F, H: in the base section, holes for securing screws like (D)
G: yet another hole with nothing in it - and a (D) screw doesn't fit

When I opened the lens, (C and D) were rattling around loose; (E) had a screw with stripped threads, which I replaced; (F) was screwed down fairly tight; and (G and H) were emply.

So the lens-base looseness was because it wasn't screwed down! The screw-post (C) could fit into hole (H) and interact with screw-posts (A and B) for a focus-stop system, but reassembling the lens by screwing the sections together means that (C) isn't in the right position to function correctly. And I don't know where to go next!

RioRico · Posted: Mon Jan 03, 2011 11:49 pm Post subject:

In case anyone is interested -- I admit defeat, and I have listed these on eBay, starting price US$0.99 for the pair. This is the listing. Y'all have fun, now.