Nikkor 105mm f/2.5 AI - Really heavy focus, normal?

[agphotography]

Hi all,

I've got a Nikkor 105mm f/2.5 AI which cosmetically is in pretty good shape but the focus ring is really heavy (stiff), my other Nikon lenses focus pretty easily so I was wondering if this is normal on this lens or if there is an underlying issue. I got it from KEH so I could perhaps send it back to them as they said nothing about a stiff focus ring.

It's not impossible to focus, but it is fairly heavy and requires about as much effort to focus as my old Hasselblad C lenses.

 

[Vilk]

All relative and subjective. You define your own "normal;" if it makes you uncomfortable, return it or have it fixed--if you can afford it. My own Nikkors span a wide range, from a relatively loose 35/2 O.C to practically fixed-focus 55/2.8 and 105/1.8. Nikon Canada quoted $174.95 to re-grease the 105--suddenly, I wasn't that uncomfortable with the stiffness, why, I was quite happy to leave it as it was!

 

[Aja B]

... so I was wondering if this is normal on this lens or if there is an underlying issue.

No, Nikon didn't design the 105/2.5 with an abnormally stiff focus ring. The lube, or what's left of it, in your lens is old.

 

[BMbikerider]

As Aja B says the lube will be old and to get it replaced is a relatively easy job for an engineer. Those who are worth engaging to do the job will probably be able to give the lens a good clean as well at the same time, it will probably surprise you what a difference that will make after it has been all done. It will be money well spent.

 

[Arvee]

I exercised mine while watching TV and it improved a bunch. I think I went through about 100 cycles in 15 minutes or so and it is definitely smoother and much easier to use.

 

[Ambar]

I have a that lens and the focus throw is indeed markedly stiffer than all my other nikon lens. My 50/1.4 AIS is a loose one which makes for quick focus action.
I always took the 105s stiffness quite naturally, believing it to be intentionally designed for easier precision when focussing (it does have a particularly long throw from close focus to infinity, as most telephotos should).

My philosophy is this:
If it makes no weird noises.
If the entire focus range feels smooth with no cranks, cracks, or bumps.
If the stiffness isn't bothering you, how fast you can focus, or the stability of the camera (you want to twist the focus ring, not the entire camera with it!).

Then leave it be and be happy!

Ps: I got lucky. My 105 was bought by my father and given to me as a gift a year or two back. My father must have purchased it and used it once, literally. I was still in original boxing, manual, and in absolute *MINT* condition. No longer the case though.........

 

[agphotography]

Well I contacted one of the sales guys at KEH that I've dealt with in the past, and he said that they would exchange it for me at no cost, though they don't have any AI versions in stock right now so they're going to send me an AIS version.

I guess that's ok in my book

 

[benjiboy]

If any lens is hard work to focus,and makes your fingers ache needs a good C.L.A., continually focusing it will make it marginally better for a while but cause wear the bearing surfaces on the lenses focusing helicoid, like running an engine without oil.