Hi Kaine, I was looking a lens on ebay, it says there is oil in blade. Do you know how bad is this.does it effect image?It is manuel prime lens. Thanks
Oil can cause alot of different problems. But if the seller doesent say it is causing any problems like stuck blades when changing aperture or affecting image quality I wouldnt worry too much.
If there's oil visible on the blades id doesn't affect image quality. It just says that there's a risk that aperture blades can get stuck, especially on an older lens. So you won't be able to change aperture. Or it may work normally for years. You never know.
I once had that issue on an FD lens. Tried to dismantle and fix it myself. I wouldn't say that it's impossible, but it my case I ditched the lens eventually. You can try if you have enough patience to do tedious, pesky and precise job, but leave it to a profeccional isn't a bad idea, especcially in case of a complex zoom lens.
Aperture problems really can render lens unusable. As "small problems" could mean that moving lever result is spontaneous aperture closing to almost random positions in 30% of cases. And repairing modern plastic zooms (any zooms are hard, btw)... Can be real pain.