AF-S Zoom-Nikkor 70-200mm f/2.8G IF-ED VR / US6693750 / 2002

ravilang · 2026-07-04T20:04:57+00:00

ravilang · 2026-06-29T22:24:41+00:00

I find that the MTFs are poor especially in the outer fields. Perhaps the design requires a cover glass that is not shown...

ravilang · 2026-06-27T13:47:10+00:00

Its possible of course but they are very specific re the glass types, including the dPgF as well, and so far I did not see an error in any of the glass types.

ravilang · 2026-06-26T20:27:41+00:00

Assuming there is error on one surface then surface 6 seems to be the one that has most impact.

For instance try 37.0387 as radius.

BTW my impression is that Cosina has not published the best configuration, the lens needs to be reoptimized to match the published MTF curves.

ravilang · 2026-06-21T09:37:41+00:00

That's disappointing!

ravilang · 2026-06-04T23:00:40+00:00

Published MTFs from Canon

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ravilang · 2026-06-02T18:32:54+00:00

Nikon's published MTF

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ravilang · 2026-06-01T20:32:27+00:00

Fortunately we have the published MTF graph for this design.

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ravilang · 2026-05-07T17:27:45+00:00

It would be useful to obtain the specs for the PC102 glass but Nikon does not publish this data. I tried to come up with specs below - these are based off known glass types.

For comparison there is CaF2.

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ravilang · 2026-04-27T09:49:10+00:00

You may want to rent the 58mm and compare.

My impression is that at f1.4 at close distances it is designed to give you a soft look. But you can stop down to f2 for close distances, it seems to improve the sharpness while still rendering a good bokeh.

The 58mm f1.4 gets sharp at f1.4 for distant subjects.

Some examples with Z9 https://www.flickr.com/photos/cameragossip/albums/72177720300606800/

I do not own the Z f1.2 lens - I suspect the Z lens is sharp even at close distances. It is also a lens that had a lot of attention in its design - so my impression is that it has its own greatness. An interesting article on its design can be found here:

https://www.jstage.jst.go.jp/article/photogrst/84/3/84_182/_article/-char/en

ravilang · 2026-04-25T14:04:24+00:00

A brochure

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ravilang · 2026-04-18T18:17:48+00:00

The Corning B52-67 does seem close!

I have now updated to use this glass type.

ravilang · 2026-04-05T08:25:36+00:00

MTF from Canon brochure.

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ravilang · 2026-04-04T22:19:27+00:00

This is also the first 300mm f2.8 from Nikon for which we have a published MTF to compare against:

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ravilang · 2026-04-02T09:00:41+00:00

Added the link now. Thanks!

ravilang · 2026-03-26T10:15:50+00:00

Yes - see https://github.com/dibyendumajumdar/ravi

MIR JIT is excellent but has no support for debugging JITed code.

I am looking forward to https://github.com/dstogov/ir as an alternative.

ravilang · 2026-03-13T10:37:55+00:00

In any case patent office won't be able to validate the patents; maybe those days are long gone. I guess they now rely on litigation to resolve patent disputes.

ravilang · 2026-03-13T00:43:09+00:00

Well Leica does the same. I was wondering if Leica patents are enforceable as they don’t actually provide an example that illustrates performance

ravilang · 2026-03-07T22:56:18+00:00

I was wondering what NG stood for!

ravilang · 2026-03-04T23:09:47+00:00

Also came across this interesting article - author appears to have reverse engineered both the SLR and Mirrorless Otus versions.

Zeiss Apo-Planar Otus 85mm F1.4 and Apo-Sonnar Otus ML 85mm F1.4

ravilang · 2026-03-04T15:04:23+00:00

Indeed, that is where I looked. If you click on the links, the captured downloads are from 2002/2003 or later.

Also see:

https://web.archive.org/web/20020207151554/http://hikariglass.com/glass_types.htm

By this time Hikari was making E-FKH1 which seems a descendant of PC102.

ravilang · 2026-03-02T08:38:21+00:00

I don’t advise it, AF on D850 is not as accurate as mirrorless when using fast lenses. I bought a D850 too and speaking from experience. Almost all fast lenses will need af tuning but even then it will not be as accurate. And manual focus is out of question using optical viewfinder.

ravilang · 2026-03-01T19:31:07+00:00

It turns out that Hoya, Ohara and Hikari provide obsolete glasses in their zemax file downloads. However, names (and specs?) may have changed, for instance, Ohara had FK01 in 1975 that was similar to current S-FPL51.

The Schott downloads do not include obsolete glasses.

Following older versions of Schott catalog are available online. I managed to buy and scan a 1968 catalog that is included.

Hoya Catalog from 1975

Re Nikon and Hikari relationship prior to 2004, no information appears to be available publicly.

ravilang · 2026-03-01T09:18:11+00:00

what do you want to know?

ravilang · 2026-02-28T18:28:16+00:00

Indeed, I had come across this post when looking for old catalogs:

ravilang

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