Nikon U10 and U20...

[Joseph S. Wisniewski]

Anyone know anything about these?

Klauss's database says they're "Metallographic" lenses, but he doesn't say what scope they were used on. Perhaps the weirdest little lenses I own, these two appear to be the "missing link" between macro lenses like the Photars, Luminars, and (of course) the Macro Nikkors...

They look just like Macro Nikkors, right down to having aperture adjustments. The differences are that they are silver (like microscope objectives) instead of black (like Macro Nikkors), the aperture collars don't have a pointer or a scale, and they're marked with magnification and numerical aperture instead of focal length and f stop.

The U10 has a yellow band and the markings

Nikon
Lens Made in Japan

U10
0.22

The U20 has a red band and the markings

Nikon
Lens Made in Japan

U20
0.33

So, they're a bit slower than a typical 10X and 20X microscope objective. They have nice, long working distances.

So, what have I got, aside from "two fun little lenses"?

[g4lab]

They could be lenses that go to a microscope projector.
I have some zeiss lenses that are essentially luminars but with a flat black finish. I know they came from a microprojector that someone parted out.
These particular lenses don't have diaphragms like the Luminars. They look like peculiarly labeled microscope objectives of 16 25 and 40mm focal length.
The flat black is to prevent reflection of the 1000 watt xenon light source behind the slide and condensor. But some projectors shield all that in a box.

More likely they are from the semiconductor industry for silicon wafer inspection.

On Luminars the scale and pointer are not f/ stops they are Stolze numbers. see Blaker,or Zeiss Luminar literature.)
I am not sure if that is the case with micro nikkors but I suspect it is.

They also might be petrographic objectives for use with a Universal stage.
Both Leitz and Zeiss made those series and they have a lot of extra working distance to accommodate the multi axis stage. Thus the na is reduced. In both those cases the objectives are labeled "U" for universal.
I had never heard that Nikon ever made such a stage but it would not surprise me.

[Joseph S. Wisniewski]

Thanks.

Would you believe Nikon did have a "universal stage".

http://www.flickr.com/photos/fluor_doublet/2274560110/

There are only two references to the Nikon U10 and U20 objectives on Google, and one of them led me to that picture. The problem is that the two references, between them, constitute about 6 sentences, and they conflict with each other.

I know about those "no diaphragm" Luminars. There's a guy with an ebay store who has several (you know the fellow: outrageous high prices on Luminars, uses the word "minty" a lot). Now I'll know to actively steer people away from him. Lenses in that kind of use tend to get a bit "baked".

Yes, I know about those charming Stolze numbers.

The Nikon equivalent of Luminars, the "Macro Nikkors", simply have their aperture scale marked in numbers from 1 to 6. I guess this lets you get back to a setting that worked for you, but doesn't try to actually tell you anything.

Hey, is Dr. Klaus Schmitt active here?

[DaveW]

Hi Joseph.

I just put "Metalographic lenses" into Google and turned up this. Would these be your lenses:-

http://nikon.com/products/instruments/l ... /index.htm

http://www.buehler-met.de/fileadmin/use ... igimet.pdf

DaveW

[Joseph S. Wisniewski]

Thanks Dave.

I'm betting those are the "children" and "grand children" of my humble U10 and U20.

The aperture control went away, and the numerical apertures increased a bit, but the purpose appears to be the same.

[lauriek]

Thanks.

Would you believe Nikon did have a "universal stage".

http://www.flickr.com/photos/fluor_doublet/2274560110/

Now that is a beautiful thing, I'm pretty sure I'd want that even if I didn't have a use for it!!

[augusthouse]

Laurie wrote:

Now that is a beautiful thing, I'm pretty sure I'd want that even if I didn't have a use for it!!

Yep, same here...

Craig

[Joseph S. Wisniewski]

Oh, I want one, too.

But wouldn't it be even cooler if it were made of brass, and had a nice rosewood base?

[lauriek]

Brass doesn't really do it for me, my fetish is more for Aluminium or steel stuff!

[augusthouse]

Here is another image.

http://flickr.com/photos/fluor_doublet/2424527762/

There are some great images in that photostream and a vast array of lenses.
I just realised that is where Joseph linked to for the Universal Stage image.

http://flickr.com/photos/fluor_doublet/

Craig

[augusthouse]

Checkout the gizmos.

http://flickr.com/photos/fluor_doublet/2520518681/

http://flickr.com/photos/fluor_doublet/ ... 697051450/

nice!

[dmillard]

On Luminars the scale and pointer are not f/ stops they are Stolze numbers. see Blaker,or Zeiss Luminar literature.)

Trivial to the point of pedantry: Luminar lenses are marked in exposure factors, not Stolz numbers. Stolz numbers are derived from the formula (f/#)squared /10, so that f/5.6 would be equivalent to a Stolz number of 3. These numbers were used for Leitz Milar and Summar photomacrography lenses, which were numbered beginning with a 2 or 3, depending on the initial relative aperture of the particular lens in these series.

Zeiss Luminar lenses are measured in exposure factors, with each lens being numbered 1, 2, 4 . . . Since lenses of different focal length also have differing initial relative apertures, the series of numbers for each focal length refers to a distinct set of f/stop values. For example, a number of 4 on the 63mm f/4.5 lens is equivalent to an f/stop of 9; the same number on the 25mm f/3.5 approximates an f/stop of 10.

I believe the confusion began with Blaker, who presents a table of equivalent f/stops for Zeiss Luminar “Stolze” numbers in his book, Field Photography. The misuse of the term was then perpetuated in Lefkowitz’ Manual of Close-Up Photography. Both of these books are superb resources, nonetheless.

[Joseph S. Wisniewski]

Trivial to the point of pedantry: Luminar lenses are marked in exposure factors, not Stolz numbers. Stolz numbers are derived from the formula (f/#)squared /10, so that f/5.6 would be equivalent to a Stolz number of 3. These numbers were used for Leitz Milar and Summar photomacrography lenses, which were numbered beginning with a 2 or 3, depending on the initial relative aperture of the particular lens in these series.

I have a Leitz Weitzler 24mm f4.5 Summar. The numbers on it are 2, 6, and 12. A hand written note taped to the very charming Leitz RMS to M39 adapter (which is beautifully engraved "Repro Summar") declares this to be f4.5, 8, and 11 respectively, so your math checks out.

Cool.

So now I know which numbers are which

Zeiss Luminar lenses are measured in exposure factors, with each lens being numbered 1, 2, 4 . . . Since lenses of different focal length also have differing initial relative apertures, the series of numbers for each focal length refers to a distinct set of f/stop values. For example, a number of 4 on the 63mm f/4.5 lens is equivalent to an f/stop of 9; the same number on the 25mm f/3.5 approximates an f/stop of 10.

And the numbers run higher on the longer Luminars. The 16mm and 25mm are marked 1, 2, 4, 8, and 16. The 40mm goes up to 30, the 63mm goes up to 60

I believe the confusion began with Blaker, who presents a table of equivalent f/stops for Zeiss Luminar “Stolze” numbers in his book, Field Photography. The misuse of the term was then perpetuated in Lefkowitz’ Manual of Close-Up Photography. Both of these books are superb resources, nonetheless.

Lefkowitz is indispensable. I actually don't have Blaker. Must put it on the "get" list.

Now, another bit of Luminar trivia.

I recently discovered that the 16, 25, and 40mm Luminars are more or less parfocal for 45mm. (the 40mm being a bit off, but it may work at some ungodly magnification ratio available on the Ultraphot, which can cover a range from 180mm to 680mm.

The 63mm, of course, can't really be parfocal for 45mm.

[Joseph S. Wisniewski]

Checkout the gizmos.

Interesting pictures.

He has almost as much stuff as me. (which probably means he has a serious problem).

Who is this "Fluor Doublet"? Is he active on this forum?

[fluor_doublet]

To the best of my knowledge, Nikon microscope objectives U5, U10, and U20 were designed for polarizing microscope equipped with universal stage, to measurement of optical axis orientation of a polycrystalline thin sample.
It might be helpful for you to check the following site;
http://www.olympusmicro.com/primer/anatomy/stage.html
Because of the sample must be sandwiched by two glass hemisphere, this objectives were LWD designed.

The optical qualities of the objectives are good, but not the best.

Please compare the photos (a seed of dandelion);
U10
http://www.flickr.com/photos/fluor_doublet/2408958093/
Macro Nikkor 19mm
http://www.flickr.com/photos/fluor_doublet/2408958095/
Luminar I 16mm
http://www.flickr.com/photos/fluor_doublet/2408958101/