Ok, ok, I screwed up...

[bobc]

I was cleaning a couple of my lenses and had them off of their respective shutters. When done, I had a shim lying on the table... I don't know which lens it belongs to: Nikon 75mm SW (1:4.5) or the Sinaron S 150mm (1:5.6).

From what Michael Briggs had written in previous posts, Nikon SW's usually have a shim. The thing is, I think it came off of the Sinaron.

I've been all over this site and others looking to see if this Sinaron has a shim but to no avail.

So, if you kind folks could take a look at your 150mm Sinaron S lens (and the Nikon 75mm SW) if you have one, and see if it has a shim under the front element, I sure would appreciate it. I bought both of these used so I don't know the vintage but here's the serial #'s to see if they are the same vintage as yours: Nikon: 673652. Sinaron: 11642032.

(I'm hoping that both lenses don't require shims because I'm gonna be short one if that's the case!) I have viewed the gg with both lenses with and without the shim in place. But, I seem to be able to focus sharply in all cases.

Thanking you all in advance...

Thanks

[robc]

if the lens is of symmetrical design, it will only make a very very small difference with or without the shim. If the lens is something like a schneider ssxl it could make a significant difference.
Fact is that quality control at the factory shims the lenses to correct for manufacturing tolerances and they should not be messed with.
Schneider offer a free check for their lenses if and only if you pay for shipping to and from their factory in germany. Doesn't help you though.

[Armin Seeholzer]

Hi
My 75 SW has no shims at all with the No. 675154 only the nude copal shutter!
Hope you can sleep better!
But always clean just one by one its much safer!
Good luck, Armin

[Kerry L. Thalmann]

I've never seen a Nikkor LF lens with a shim installed - doesn't mean they don't exists, I've just never seen one.

On the other hand, my 150mm APO Sironar-S has a shim between the front cell and the shutter. I'm always very careful to replace it when removing the cell from the shutter to clean it. That doesn't mean all 150mm APO Sironar-S lenses have a shim, but mine definitely does. Some probably do and many probably don't. The shims are used to fine tune the performance of each individual lens during final assembly/test.

BTW, my 110mm Super Symmar XL also has a shim between the front cell and the shutter.

Kerry

[darr]

bobc and robc ... related?

I hope it works out for you bobc.

[Ted Harris]

It should work ok. I have to admit that one of my longer lenses (360 Apo Germinar) used to hace a shim which got lost in the field several years ago. I have seen no change in performance since gone. Not recommending one throw away ones shims but in this single case all is ok and, yes, I worried about it for months.

In response to Kerry, my 110 SSXL in a Compur shutter doesn't have a shim and didn't come with one new from Badger.

[Colin Graham]

On the other hand, my 150mm APO Sironar-S has a shim between the front cell and the shutter.

Kerry

Mine has a shim too if it's any help.

[Michael S. Briggs]

Both Nikkor-SW lenses that I have shims between the shutter and the front cell. I have a small yellow paper warning insert that came with some LF Nikkor (probably one of these) that lists a warning applying to the Nikkor-SW 90, 120 and 150 mm f8 lenses, warning that you should replace the washer if you disassemble the lens. The insert has the notation "83.11.E" next to "Printed in Japan" -- the notation is probably a datecode for 1983. Since the fast Nikkor-SW lenses were made before 1983, it maybe that the shim washers are only used on the f8 models. The two Nikkor-SWs that I have are f8 models. If true that only the slow models need to be adjusted with a shim washer, it's a mystery to me why this would be so.

Isn't the Sinaron S an Apo-Sironar-N?

I can't say whether the Apo-Sironar-S or the Super-Symmar-XL that I have have shim washers. The front cells won't unscrew with the amount of torque that I am willing to apply. Maybe some threadlocking agent has been used? Perhaps the manufacturer's way of preventing the photographer from losing the shim washer?

[Eric Biggerstaff]

My Sironon-S has a shim between front cell and shutter.

[Sheldon N]

My 150mm Sinaron S also has a shim between the front cell and the shutter.

[bobc]

RobC and I can't be related. I'm sure he's a lot smarter than I am....

Thanks for the input folks on the Sinaron!

As a check, anyone have a Nikon 75mm SW they're willing to unscrew the front element on to check that there's no shim?

Thanks!

[robc]

bobc and robc

sounds a bit Beatrix Potter doesn't it. No relation.