Does your 90mm f:8 Nikkor have a brass shim on the rear element?

[Kevin Crisp]

Only 0.002" thick? I ask because I've got a nice one (no shim) and a beater with shim. On the rear element. Thanks.

[Andrew]

no shims on mine... front or back

[Kevin Crisp]

Thanks

[480sparky]

Mine is sans shims.

[Andrew]

Q. is the beat up one still in the original Nikon shutter or has someone swapped it into a non-Nikon branded shutter?
if the cells have been swapped between shutters, maybe the shim is from the lens that was originally on that shutter ???

[tih]

The shim *could* be original, of course. It may have been decided during QC that this particular lens/shutter combination needed that extra 2 thou. Reading this FAQ entry from Flutot's Camera Repair, it seems they expect this to be the case from time to time: http://flutotscamerarepair.com/FAQ.htm#RemoveLens

[Andrew]

The shim *could* be original, of course.
indeed, it could be.... but I'm wondering if it's not original because I have a few lenses with shims and they're all on the front

[Kevin Crisp]

I am a little embarrassed to fully explain why I am asking but I will. I was making a list of all my LF lenses for insurance purposes and figured I'd clean them as I went. A few required removal from the shutter to clean the inner element as there was some haze present. When I got done I see this spacer sitting on the counter. It had to be from a Copal 0 lens, it had to be one I took out of the shutter, which narrowed it down to the point where I was almost sure where it came from. It doesn't really fit the Nikkor front element but is a nice fit for the step on the back element. I have a vague recollection of this being there on this lens, which I had to fully disassemble when I bought it due to some fungus which thankfully left no permanent etching. So anyway, I thought I'd ask.

It has been my experience that shims are more likely a creature of wide angles, and that 0.002 inches of spacing in a longer focal length would not make a difference in a photo. I've used a loop looking at the aerial image with this one with and without the shim and I honestly don't see a difference.

Anyway, thanks to those of you who took the time to check. I'll probably run a test with the AF resolution chart and some film just to be safe.

[Bob Salomon]

I am a little embarrassed to fully explain why I am asking but I will. I was making a list of all my LF lenses for insurance purposes and figured I'd clean them as I went. A few required removal from the shutter to clean the inner element as there was some haze present. When I got done I see this spacer sitting on the counter. It had to be from a Copal 0 lens, it had to be one I took out of the shutter, which narrowed it down to the point where I was almost sure where it came from. It doesn't really fit the Nikkor front element but is a nice fit for the step on the back element. I have a vague recollection of this being there on this lens, which I had to fully disassemble when I bought it due to some fungus which thankfully left no permanent etching. So anyway, I thought I'd ask.

It has been my experience that shims are more likely a creature of wide angles, and that 0.002 inches of spacing in a longer focal length would not make a difference in a photo. I've used a loop looking at the aerial image with this one with and without the shim and I honestly don't see a difference.

Anyway, thanks to those of you who took the time to check. I'll probably run a test with the AF resolution chart and some film just to be safe.

The AF made a nice chart but your lens was not made for copying a flat chart at near distances. Go shoot a brick wall.

[Kevin Crisp]

I was not going to shoot it at a near distance. I have three charts us one in the middle left and right of the frame.

[IanG]

Shims are used occasionally with LF WA lenses, the manufacturer decides when and where as it depends on the particular front/rear cell combination, it's not standard for every similar lens of the same type. It's individual lens optimisation.

Ian

[john borrelli]

I owned one of these a long time ago. my copy did have a shim.

[LeeSimmons]

My copy has a shim.

[fishbulb]

No shims on my Nikkor 90mm f/8 rear element. Front element is too tight to remove.

[Kevin Crisp]

I think I'm going to conclude mine had a shim. Thanks for everybody who went to the trouble to check.

[dentkimterry]

My just purchased Nikon 90mm f8 has a shim on the front element but it is broken. It may still work though to hold the spacing. Is there a source for these new?
Terry

[EdSawyer]

should still hold the spacing fine.

[David Millard]

Hopefully this old thread will survive a revival. My Nikon 90mm f/8, purchased about ten years ago, has a shim in the front. Additionally, there was a printed insert in the box, which I have copied.
155631

155632

[Per Madsen]

There are no shims on my example.