Oil on aperture blades

[janvanlaethem]

I'd like to purchase a 13.5 cm for a Nikon rangefinder. The person who is

selling the lens mentions some oil on the aperture blades and some minor dust

spots inside the lens.

 

I'm not too concerned about the dust spots, but I'd like to know your

experience with oil on the aperture blades. Could this in any way affect

picture quality or the normal functioning of the aperture blades? Is this

something that could get worse over time and render the lens useless?

 

Thanks for any information you can give me.

 

regards

 

Jan

[winfried_buechsenschuetz1]

Oil on the aperture blades will make them somewhat sticky. This does not matter too much with a rangefinder lens. If the blades are too sticky the aperture ring may get stiff, and/or the blades may warp and get out of their guide holes when closing/opening it. In severe cases the guide pins of the blades may break.

 

Anyhow, if there is not too much oil on the blades you can shoot along with such a lens. Maybe there will be somewhat more flare due to increased reflections from the shiny blades (usually they have a mat surface). I have read that on some lenses there might be a slight haze on inner surface due to outgasing ingredients of the oil layer.

 

PS. I made great shots (well, at least from a technical point of view) with a Canon f/1.2 50mm lens of which the aperture blades look as if they were intentionally coated with grease.

[steve_bellayr]

I have a 50mm lens from that period & camera. It has oil on the blades & I never had a problem. I have read others have had no problem with rangefinder lenses with oil on the blades. However, if it were an SLR lens I would pass as that could be a problem.

[luis triguez]

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=002hwr

[patrick j dempsey]

With prime lenses it usually takes about 10 minutes to take the rear of the lens apart, clean the blades off with some Q-tips and put it back together. You can get yourself some great deals on glass if you are willing to put in that effort. As long as you are careful and pay attention to what you are doing its not difficult for more lenses. Zooms are somewhat more complex.