Lens recalibration

[justiny]

Hi
My Nikkor-m 300mm F9 seems little too soft compared to 75mm grandagon-n and 210mm apo-sironar-n. Is there any place that can re-calibrate the lens?
OR just my expectation is too high.


Thanks

[xkaes]

You could start by defining "re-calibrate".

[Greg]

Are we talking about the distance between the front and rear groups of elements? Over the years I've come across a few (3) optics mounted in shutters that projected mediocre images. In those three cases the distance was more than it should have been and I'm talking in a couple of mm's.

[Leigh]

In those three cases the distance was more than it should have been and I'm talking in a couple of mm's.

That's a huge error.
2mm = 0.080".

Precision machine work can easily hold a tolerance of +/- 0.001" (0.0254mm).
Tight tolerance work can do 1/10th of that error.

- Leigh

[Bernice Loui]

25.4mm per inch..

2mm / 25.4 = 0.07874 inch.



Bernice

[Doremus Scudder]

Hi
My Nikkor-m 300mm F9 seems little too soft ...

I had a similar problem with my Nikkor M 300mm when I first got it. After a bit of examination I determined that the lensboard I had it mounted on was preventing the rear element from seating all the way into the shutter barrel. A bit of woodworking fixed the problem and the lens performed spectacularly thereafter. Maybe you have a similar issue?

Best,

Doremus

[Luis-F-S]

You can send the lens to a shop like SKG and have them check the alignment. I've done that with the number of my lenses

[Leigh]

25.4mm per inch..
2mm / 25.4 = 0.07874 inch.

Hi, Bernice,

Brain fade.

1mm = 0.040" 2mm = 0.080".
That's the rough equivalent used by machinists for visualizing dimensions.

Note to self: Do not post before coffee.

- Leigh

[Jim Andrada]

The machined leader block on LTO tape drives was held to around 5 micron tolerances. At one point it was costing $13 for a piece of Delrin about half the size of your thumbnail. Finally after only 5 - 10 years of trying we were able to hold tolerance in a molded version.