Slightly sluggish aperture on 45mm f/2.8 AiP

[Erik Lund]

There is a ball race in manual focus lenses that must remain dry, unlubricated. The stop down lever in the lens runs on this ball race. The lever must run very fast to stop down to minimum aperture and to keep up with a motor drive. I wonder if those ball bearings could have a tiny bit of oil on them that separated from the grease. That's probably unlikely. I don't see lube contamination of the aperture blades. It could be just starting.

I'll bet there is something impeding the aperture stop down lever in the lens just a bit.

If the camera is set manual exposure and there is no change in the exposure settings is the problem still seen? If so I'd have the lens serviced.

Dave

Are you sure this has a ball race? Normally only old lenses, and long build length has this,,,,

[richardHaw]

this is weird. the lens has to be opened

it is possible that the bearings have gummed up but i have not seen anything like this even in the worst of the junk nikkos that I have worked with. but since this is a cosina-made lens then the engineering might be different.

[Roland Vink]

The 45P is made by Cosina?

[richardHaw]

The 45P is made by Cosina?

Yes

I also suspect the 45mm f/2.8 GN as well because the engineering techniques used are VERY different from what Nikon uses and the choice of hood type is much more in line with cosina. here in Japan, when a company wants to make a product that is cheap but cannot produce it cheap enough themselves then they would outsource it elsewhere - in this case, Nikon to Cosina. some would even claim that some of the Series E lenses were subcontracted as well but i cannot confirm that.

[David H. Hartman]

I can't say I've seen a ball race in a Nikkor that was gummed up. I think I fought with one while reinstalling the meter coupling lever in a PK-11. A PK-11 soon modified can be used to install a pre-AI lens on current and recent dSLR(s) like 55/3.5 compensating aperture Micro-Nikkor. I wish I had it back and without the meter coupling.

Dave

[Roland Vink]

Hmmm, interesting. I always thought the 45P was made by Nikon. It is a unique lens - pity they didn't make more like it.

I have seen the Nikon branded AIS 35-70/3.5-4.8 and 70-210/4.5-5.6 which are made by Cosina. Apart from the rather "Series-E" type build, the giveaway is the number of aperture blades - 6 for the 35-70 and 8 for the 70-210 - which is not Nikon style at all. Nikon last used 6 aperture blades with the AI 50/2 and 55/3.5 micro until the late 1970s, and never made SLR lenses with 8 blades.

I'm not sure about the 45GN - this lens is very different by virtue of the GN mechanism, for example the focus ring turns the opposite way from other Nikkors and runs on a cam instead of a helix. Wouldn't that explain the different engineering? Or are there other differences - choice of materials, style of construction - which point to a different manufacturer? The hood is unique too, but even if it was made by a third party, surely it would be designed by Nikon. I don't have any hard evidence either way, but always assumed it was made by Nikon.

[Akira]

I though 45P (as well as Series-E) was made by Tokina.   

[richardHaw]

I can't say I've seen a ball race in a Nikkor that was gummed up. I think I fought with one while reinstalling the meter coupling lever in a PK-11. A PK-11 soon modified can be used to install a pre-AI lens on current and recent dSLR(s) like 55/3.5 compensating aperture Micro-Nikkor. I wish I had it back and without the meter coupling.

Dave

i avoid opening these up if i can help it
they are a pain!

[richardHaw]

Hmmm, interesting. I always thought the 45P was made by Nikon. It is a unique lens - pity they didn't make more like it.

I'm not sure about the 45GN - this lens is very different by virtue of the GN mechanism, for example the focus ring turns the opposite way from other Nikkors and runs on a cam instead of a helix. Wouldn't that explain the different engineering? Or are there other differences - choice of materials, style of construction - which point to a different manufacturer? The hood is unique too, but even if it was made by a third party, surely it would be designed by Nikon. I don't have any hard evidence either way, but always assumed it was made by Nikon.

https://richardhaw.com/2016/03/13/repair-gn-auto-nikkor-45mm-f2-8/

the use of a cam for focusing might be necessary because it has to turn at the same rte as the aperture ring also, the tooling used felt "alien". I am not sure, maybe I can confirm this one of these days when i meet Haruo Sato.

the 45P is special. I always wanted one but I still cannot find reasonably priced one or junk the 45P felt like a chunky lens by the way. very dense. maybe mr Ang will open up his 45P soon and we will see what's inside

[richardHaw]

I though 45P (as well as Series-E) was made by Tokina.   

no, Cosina
it seems that Cosina has a long history working with Nikon. Tokina on the other hand was setup by former Nikon engineers that were pissed off.

http://page12.auctions.yahoo.co.jp/jp/auction/p508776400

this one is reasonably priced, but silver (I want black). too bad I cannot play the auctions now. had a conversation with my wife after getting the NOCT

[Erik Lund]

https://richardhaw.com/2016/03/13/repair-gn-auto-nikkor-45mm-f2-8/

the use of a cam for focusing might be necessary because it has to turn at the same rte as the aperture ring also, the tooling used felt "alien". I am not sure, maybe I can confirm this one of these days when i meet Haruo Sato.

the 45P is special. I always wanted one but I still cannot find reasonably priced one or junk the 45P felt like a chunky lens by the way. very dense. maybe mr Ang will open up his 45P soon and we will see what's inside

As can be seen in the link the old 45mm GN doesn't have a ball-race or ball-bearing - It' actually looks more or less identical to most short Nikkor lenses in this regard.

The 45mm Ai-P,,, Balls,,, highly unlikely,,,

Cosina,,, urban legend so far 

[chris dees]

There's one for sale in the "Classified Ads" section (shameful plug )

[Fons Baerken]

There's one for sale in the "Classified Ads" section (shameful plug )

I have been thinking about it, i am not familiar with this lens, never tried one

[FGAng]

Thanks to so many responses, directly or indirectly.

Erik the shot was through a car window, does not appear too seriously over exposed.

Now a series of sunset shot out of the window (I am quite home bound after work).  I think the problem is clear to see.

f/2.8


f/4


f/5.6


f/8


f/11


f/16


I quite like the OOF look (Bokeh?) of this lens.  at f/2.8

[John Geerts]

I have been thinking about it, i am not familiar with this lens, never tried one

Sharp, colourful, Voigtlander-like-  works very good with close up lens and extenders.  And lovely small.  What more do you want