Oly 50/1.2 harder to open up than stop down

[ChrisP]

I recently got a Olympus 50/1.2. When using the lens its harder to open up the aperture (go from f16 to f11) than to stop it down (11-16), especially for smaller apertures. Is this normal or should I let John Hermanson take a look at it? I'm sending him a few cameras anyways.

 

[Frontman]

You might as well let John take a look at it, the 50/1.2 is worth the expense to CLA. The lubricant in the aperture ring is probably dried up, and needs to be cleaned out and replaced, which means the lube in the helicoid lube could probably use replacement as well. The proper grease is not so easy to find, and a few grams cost $40 or so. Using common oils and grease can cause haze, and they tend to seep into places where you don't want them to go.

 

[plummerl]

I would definitely have John look at it. With my 50/1.2, I don't even think about any resistance in the aperture ring, either direction.

 

[John Hermanson]

Is it hard to turn while on a camera or separately? If on an old OM-1, going from 1.2 to 16 would be harder because you are pushing against the coupling ring inside the body. John