jerryc41 Loc: Catskill Mts of NY

I've heard about the leaves sticking, but that's repairable, although it would be expensive. As you say, electronics do go bad. LensRental had an article about that, and focusing motors do fail. I've never experienced any kind of lens failure.

TomV Loc: Annapolis, Maryland

Up to this post, no one has experienced lens failures but yet there is a bevy of hoggers that claim you should not buy grey market since you will not have the US warranty. This is not consistent reasoning since clearly the warranty is rarely used. In my brief experience I have never had a lens failure and most are purchased used.

Robert Bailey Loc: Canada

I've been a photographer for 42 years and have had only one lens fail in that time. It was repaired under warranty.
I have unfortunately had problems with mildew growing inside lenses when they were stored in an area with too high humidity.

DavidJon Loc: Ada, Oklahoma

Too true. My 40 and 50 year old Nikkors, Takumars and Rokkors still work as well as the day they came off the dealer's shelf. How long my motorized, auto-focus, electronic lenses for my DSLRs will last I have no idea but in 40 years I expect they will be little more than objects of curiosity.

RWR Loc: La Mesa, CA

Disuse is bad for manual lenses. Use is bad for automatic lenses.

Robert Bailey Loc: Canada

RWR wrote: "Disuse is bad for manual lenses. Use is bad for automatic lenses."

A wise statement, my friend!

camerapapi Loc: Miami, Fl.

Not me.

Robert Bailey Loc: Canada

Not you what?

lamiaceae Loc: San Luis Obispo County, CA

The Auto-Takumar lens(es) that I am (was) talking about are earlier and physically smaller than the standard Pentax 49mm filter size. My Auto-Takumar 35mm f/3.5 lens has a lever on the side to manually stop-down the iris. You are correct in that Takumar lenses had auto aperture. But the pre-Spotmatic, pre-Super Multicoated Takumar lenses are different from that. On the later Multicoated-Takumar and Super-Multicoated-Takumar lenses the auto (open/close) iris switch is freely reset-able when used on both Screw Mount (M42) or K-mount cameras. Where as when I've put a Auto-Takumar on a K-mount camera if you "throw" the switch you can not reset it with out first removing the lens and by hand pushing the Pin in. The K-cameras lack the linkage and must use the screw mount lenses fully manually (but yes you can open and close the iris manually for focusing and checking DoF), but the old Auto-Takumars are in essence reversed as to the switch lever and Pin when and how the iris is open or stopped down on a none Screw Mount body. I have never handled a per Spotmatic Pentax so I'm not sure of its precise actions. Meaning the Auto-Takumar lenses made sense on the pre-K-mount cameras. So in my original post I said "auto nothing" to mean the auto-Takumar lens is a pain in the ass on a DSLR because if you bump the switch you have to dismount the lens to reset it -- I was being sarcastic at my own lens.* I actually own both types of Takumar lenses so I'm not talking hypothetically. See attached photo of both types of lenses. The rears look similar both with M42 threads. (I believe even earlier "Pentax" lenses were M39)

*I purchased the lens for potential IR & UV use because I believe it has less coating than the later models. The IR images I get with it are certainly different but it remains to be seen if it is an improvement. My other Takumar lenses work fine manually on both my K-mount SLR and DSLR cameras.

The Linkage Inside Is Different Too

(Download)

dreamon

I've been shooting seriously since 1975, and I've never suffered a lens failure, not even oily diaphragms. Knock on wood.

lamiaceae Loc: San Luis Obispo County, CA

Normally you only get oily diaphragms (blades, leaves) if some previous fool oiled instead of cleaning them.

dreamon

Agreed. Graphite should be the weapon of choice.

CPR Loc: Nature Coast of Florida

This one is roughly 70 years old and still going fine. Have Nikon lenses from the 50's that still work as well. Not so for me but the lenses are doing fine.

Robert Bailey Loc: Canada

Have you looked at buying a digital back for your 4 x 5 cameras?

Kissel vonKeister Loc: Georgia

According to Ken Wheeler who dismantles lenses to investigate and repair them, the diaphragm and shutter blades are now largely Kevlar with no lube required.