Lens Question

[fightheheathens]

I bought a Nikkor 50mm f/1.4 AI-s lens the other day on ebay
and i got it in the mail this morning.
everything about the lens except for one thing looks great
focus is smooth, no scratches, dust, fungus, haze in the lens
aperature ring snaps nicely. However i was looking at the aperature
blades to make sure they were nice and everything appeared fine
until f/11. the aperature blades do not appear to move between
f/11 and f/16. My question is, is this a cheap fix, or do i send the lens
back to the seller. I dont mind spending a little to get this fixed, but anything
more then 20 bucks and i might as well send it back and look for a different one.

 

[Big Mike]

Are you sure that they are not moving? By F11 the actual distance that the blades have to move from one stop to another is very small.

 

[fightheheathens]

i'll have to check again when i get back home from work, but i didnt see any movement. it seemed like one of the blades may not have been closing all the way because the aperature was not completely round at f/11. Im not sure. On my old pentax lens while there wasnt much movement between f/16 and 22 i could see some movement and i didnt see it here.
I also moved the coupling lever up and down and everything seemed smooth, no kinks or the like.

Granted i only looked at this as i was running out the door for work. so ill do a closer examination later tonight.

I would be very disappointed if i have to reture this lens as the glass appears to be in excellent condition and it looks as if this lens was very well cared for

 

[fightheheathens]

ok, so i got home and i looked over the lens very well.
The aperature blades do not move from about f8 and 1/2 to f16.
the aperature hole appears to be fine nice and round, it doesnt look like any of the blades are sticking.

I then looked at the coupling lever. this comes out of the back of the lens between the mount and actual rear element. There is a little slot that this lever travles in. wide open there is about 2 mm of travel distance from the lever to the top of this slot. as i close down, the lever moves along fine until i get to f8 and 1/2 At this point the slot that the lever moves along in ends.

In the discription of this lens, the seller said that the lens had been serviced by a professional. I am wondering if this means the rear element was removed to get at the aperature blades and when the cover was put back on this rear element was rotated slightly, even 1 degree might be enough.
anyway what that means is that there is extra travel (ie more space for the coupling lever to move up) even when full open, but because of this there is not enough space for the coupling lever to move down thus preventing the blades from closing all the way when i go to f/16

Does this sound possible?
anyone?

here is a picture to show you what i mean

 

[Don Simon]

If the problem is as you describe, you may be able to fix it yourself - have you tried removing that rear holding ring?

 

[jwkwd]

See if the part on the lens mates properly to the camera body. The lever inside the body could be worn or bent. If the body is also new to you, that lever could have had a non Nikon lens forced on that "tweaked" it a little. If possible, find another Nikon body and see if it works right. Older Nikkor lenses had 3 screws holding the mounting plate the lens body, yours has 5. It could be converted to AI-s and the screw positions are off..............Well maybe not, I just looked at a couple of mine, and one has 4 screws.

 

[fightheheathens]

hmmm, well its not the body...cause i havent gotten that in the mail yet.
i pick it up tomorrow at the post office.

i talked with the person i bought it from and it sounds like
she had it serviced by a repairman who cleaned the aperature
blades. my guess is that when he put the rear cap back on
it got turned just a little. I might try to fix it myself
or i will have to wait till tuesday for the local shop to fix it and
i dont want to wait that long