If you fix this problem, I favor a very, very small dot of JB weld (epoxy) as I always have it around for many other purposes. It too requires that the lens remain unassembled for a few days as with all glues and epoxies, but after 24 hrs there is less out gassing and it will NEVER fail. In addition to being useful to bind things together, this stuff can be used to form parts and can be filed, sanded, milled, drilled and polished. I've used it to bed the receivers of two of my rifles.
Still, I agree with Anthony. The A50/1.4 is an excellent lens with better construction. Regards, Bob... --------------------------------------------------- "Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin From: "Anthony Farr" <[EMAIL PROTECTED]> > The A50/1.7 has a common fault with its aperture ring that involves the "A" > button. The button sits in a strip of spring steel that is anchored at each > end to the plastic of the aperture ring (by small rivets IIRC). One of the > rivets sometimes fails causing the steel strip to stand proud at that end, > which snags a recessed area of the ring's inner surface and prevents > movement to apertures below f9.5 (again IIRC). It happened twice to my > A50/1.7, the first time it was sent out to repair, the second repair would > have taken cumulative maintenance costs higher than the lens's original > value so I decided to do a home repair. If that failed I would have binned > it. The repair was actually very simple but you have to be careful of the > infamous "projectile balls" inside the lens mount. If as in my case super > glue is part of the process then you need to leave the whole lot open for a > few days so you don't get a filmy deposit on the glass. > > This is a powerful argument in favour of the A50/1.4, i.e. all metal > construction. > > From: "Joe Wilensky" <[EMAIL PROTECTED]> > > > I believe there's a build quality issue with the SMC-A 50/1.7 that > > doesn't exist even with the similar A 50/2 -- I probably read about > > it here, and it happened with the A 50/1.7 I owned for a while. The > > f-stop ring detents deteriorate in some way, I don't remember if it's > > because of a gear or some plastic part. But mine worsened noticeably > > while I had it; the aperture ring developing a stiff and uneven feel. > > This issue doesn't exist with the M 50/1.7, and it doesn't exist with > > the A 50/2 or the A 50/1.4. That build quality issue alone may be > > reason enough to select a different lens, despite the A 50/1.7's fine > > optical qualities.
