Oil on aperture blades

Does this still happen on newer lenses in the past 10 years or so? I remember this was something you always checked for when buying used but I never hear it mentioned anymore....

FEChariot wrote in post #17676915
Holding the shutter button down half way does the same thing.

Good question. I know the old C/Y-mount lens I used to use had manual apertures. I could just dial down to f/29 and look at the blades. It is a lot harder to seem them these days.

I had an EF lens older than me(88) and it didn't have any issues.


I also have some lenses older than my parents(late 50s early 60s) that dont have issues.

The lenses I have bought in the past that did have a alot of isses where mostly 70-80s pentax stuff. Dreaded oil on aperture, and even worst stuck aperture.

If you have a body with you, you can actually step it down and hold the button while you remove the lens and it will keep it's stepped down position. Then you can check it from the rear.


But this isn't helpful when you spot one some place when you don't have a body with you. Nor with a seller on ebay that doesn't have access to a eos body.

I bought a nice contax lens on eBay a couple years ago that was described as mint. Until I put it on my yashics and the blades wouldn't open up after I pressed the shutter. That went right back. I have not heard about this at all with newer lenses and wondered what they do different.

Frodge wrote in post #17677037
I bought a nice contax lens on eBay a couple years ago that was described as mint. Until I put it on my yashics and the blades wouldn't open up after I pressed the shutter. That went right back. I have not heard about this at all with newer lenses and wondered what they do different.

Not sure where this oil on aperture blades came from but I assume it is amateur repair techs. Oil is a bad idea for this application as it will tend to gum up over time. What they do different (and what good manufactures did from the beginning) is just leave them dry. Properly machined and assembled aperture blades don't require any lube.