Sometimes you don't want to know the truth...

[Akira]

After reading this inspiring thread by Bjørn (Rørslett):

http://nikongear.net/revival/index.php?topic=250.0

I set the function of Fn button on my trusty D7000 (with its AF calibrated at Nikon service) to its default "Preview" and found this. 

To keep the aperture stopped down, this image was shot with the camera set to the live view mode.  The lens is AF-S 35/1.8 stopped down to f2.5.  The aperture looks equally ugly at 2.8.  The problem is solved at f4.0 and smaller.

No, I don't blame Bjørn.   

[armando_m]

Akira, you mean ugly as in being decentered  ?

[Akira]

Yes.  The aperture blades are all-too unevenly closed.

[pluton]

Is the aperture opening really as off-center as the photo makes it look?
If it's centered, but just uneven around the edges, it is probably best ignored.

[Akira]

Keith, yes.  The image is not shot perpendicular to the optical axis, but the aperture is obviously off-centered when the lens is looked into properly.

[Erik Lund]

Needs a quick visit to the Nikon service...

[Akira]

Needs a quick visit to the Nikon service...

This sample was bought last month, so the repair will be covered by the warranty.

I had similar experience with Ais 105/2.5 bought new.  Nikon repaired it, of course, under warranty.

[Øivind Tøien]

I found the same in an excellent grade 200mm f/4 AIS that I got from Roberts. I called them and asked them to check their other 3 copies for sale, and they all had part of the same asymmetric unevenness along the edge of the aperture, but one one less than the others. Bjørn also informed me his copy shoved a little of the same. Roberts agreed to exchange with the best one, which was a very nice copy, and I have not thought about it since.

[Akira]

My earlier sample of DX35/1.8 had no such problem.  So, I'm not that worried about the repair.

I haven't bought that many brand new Nikkors, but the defect rate of the ones I have bought over the years are disappointingly high.

[Akira]

Took my troubled 35/1.8 to Nikon service.  The attendant looked into the lens and immediately noticed the problem.  The lens will be repaired, of course, under warranty.  The aperture unit seems to be going to be replaced.  The repaired lens will be sent to me via parcel delivery service at their cost.

[Akira]

The lens came back from the Nikon service.  Now the aperture looks noticeably smoother at f2.5, and its opening is well centered.  The rep said that they examined several different aperture unit and chose the best possible one.

While I truly appreciate their effort to fulfill my somewhat picky requirement, I would have to say that I'm still skeptical about their QC, because the much earlier sample that I had didn't suffer from that problem.

Oh, well...

[Roland Vink]

The rep said that they examined several different aperture unit and chose the best possible one.

If they have to cherry-pick to find a good unit, that suggests a lot of variation, little consistency and poor QC...

[Akira]

If they have to cherry-pick to find a good unit, that suggests a lot of variation, little consistency and poor QC...

Indeed, yes...or the design of the unit can be questionable.

[Erik Lund]

It could also say that the tech guy had very high standards!

Picking out the best could indicate a selection from another aspect, most responsive return, firmness, size...

[Akira]

It could also say that the tech guy had very high standards!

Picking out the best could indicate a selection from another aspect, most responsive return, firmness, size...

Erik, I agree with you so far as the tech guy in charge of this particular repair goes.  I'm questioning about the QC of the reguar product line.  I think the earlier samples of the same DX35/1.8 model suffered less from the variation.