Lens Question

[justin_wall]

I wasn't sure where to post this Question. Is it bad if the aperture blades

have oil on them? If so what does that mean? I recenlty upgraded to digital &

sold my 35mm camera & all my lenses on Ebay. One wininng bidder claims that

there is a problem with a wide angle lens, that there is oil on the aperture

blades and the aperture ring is slow. I never had any problems with it. ANy

advice would be appreciated.

 

Thankyou,

[Ed_Ingold]

Oil on the aperture blades is definitely bad. It is due to migration of oil from the grease in the focusing mechanism. It is aggravated by excessive heat, as in a parked car in the sun. Oil on the blades slows or stops their normal operation, which is to close down to the preset aperture at the time of exposure.

 

It costs about $100 (maybe less) to have a lens cleaned and lubricated. I suggest using a factory-authorized service for this, rather than a camera shop.

[todd peach seattle, washi]

Edward hit the high points well. If you aren't aware of the problem, it can take a bit of investigation before it smacks you on the forehead.

 

On a Nikon lens, a 'sticky' aperture usually results in overexposure, and the problem is related both to the aperture in use and the shutter speed. If you're in the habit of shooting at or near wide open most of the time, you may be blissfully unaware of the problem. If you shoot color negative film, you may never notice that your negs are a stop or two overexposed.

 

The 'sticky aperture test' is pretty standard for me when inspecting used gear. Depending on the value of the item involved, you may be far better off just refunding the money and relisting it with full disclosure of the problem and call it 'as is'.

[Brian]

If you never had any problems, perhaps the oil isn't there, and what you've got is an eBay buyer who's changed his mind and wants his money back.