WTH is going on with my lenses?

[Nhyrum]

I've got a Minolta x 700 that I have (had) two lenses for. A five star brand 28-80 macro and a rokkor-x 75-200.

Both, literally over night started acting up. The 28-80 had some malfunction of the macro and focal length rings. The night before I was taking a few pictures with it and it was a bit sticky pulling it out of its macro mode(there's a little button you push that let's it move past a stop and return to normal) but with patience it would work. Next morning, the macro ring would return normally, but the focal length was stuck at 80mm. I'm macro it was usually confined to 70-80 and after returning it to normal, would regain full use of it's focal length. Didn't even have the lens a few days, it stayed on my camera, which stayed on my dresser.

Now for my 75-200. I've been using it quite a bit, and recently it's got a spot in the slider on the lens where it gets pretty tight. I've had it a few weeks now and it's always been really smooth and I've been really pleased with it, and both of my lenses starting at shite the bed is pretty frustrating. The 28-80 is already in pieces.

What the hell would make the lenses do that, literally with nobody touching them? Like... What the hell, man ..

 

[wfooshee]

Age and entropy. Oil gumming up and resisting smooth motion of the parts. Fasteners back out or loosening, or the hole a fastener passes through wearing into a slot. I do a little bit of clock repair from time to time, and it's amazing what happens to the pins on the gear wheels, and the bushings they ride in, over time. Anything with moving parts will experience wear, and parts that wear don't stay in the same place they're supposed to. With clocks, that makes them stop as a gear gets a little sideways and jams. With lenses, I can easily see some lever of catch or pin not doing what it's supposed to do as a result of wear.

 

[cgw]

Agree with above. It's age-related likely. Petroleum-based lubricants used in 70s-80s cameras/lenses can and do dry out and gum up--often with unpredictable results. I'd look for replacements if the price is right.