Apo- and Process Nikkor info

[Asher Kelman]

Here: http://www.galerie-photo.com/apo-pro...ikkors-en.html in English.

Some was taken from catalogs posted here: http://savazzi.freehostia.com/photog...literature.htm

Hello Dan,

Thanks for sharing the interesting data you have assembled on Apo-Nikkor lenses.

There's a feature that I find puzzling and for which my searches have not found an answer. I have a 750 mm f11.0 Apo-Nikkor and I'm wondering about the function of the 0-100% scale. I can't see any changes looking through the lens as the dial is moved. It seems to provide access to a slot for filters or aperture plates perhaps. But what do the percent scale markers indicate?

Thanks,

Asher

[ic-racer]

Hello Dan,

Thanks for sharing the interesting data you have assembled on Apo-Nikkor lenses.

There's a feature that I find puzzling and for which my searches have not found an answer. I have a 750 mm f11.0 Apo-Nikkor and I'm wondering about the function of the 0-100% scale. I can't see any changes looking through the lens as the dial is moved. It seems to provide access to a slot for filters or aperture plates perhaps. But what do the percent scale markers indicate?

Thanks,

Asher

Here is a quote from the PDF:

These plates [waterhouse stops] can be tilted [rotated?] within the slot in accordance with the requirements of the using situation. From Apo-Nikkor PDF

There is an index line on the waterhouse stop. I think the 0-100 marks are index marks to align with the mark on the waterhouse stop to allow you to reproduce your special effect. Is there a "%" on yours?

[Asher Kelman]

Here is a quote from the PDF:


There is an index line on the waterhouse stop. I think the 0-100 marks are index marks to align with the mark on the waterhouse stop to allow you to reproduce your special effect. Is there a "%" on yours?

Thanks ic-racer,

Yes, it goes from 0 to 90%.

So I gather these were some kind of plate with a pattern of multiple holes so soften the image perhaps? If so, do you know who might have such stops I could copy?

Were they actually called Waterhouse stops? There's a beautiful working aperture so I can't understand why a simple Waterhouse stop would be preferable to using the changeable aperture.

Asher

[Dan Fromm]

Asher, Waterhouse stops with non-circular holes were used in making half-tone plates. The hole's shape is the dot's shape, the hole's orientation is the dot's orientation.

Yes they're called Waterhouse stops, after their inventor (?), John Waterhouse. You can read about him in your copy of the VM. If you don't have a copy of the VM, get one. Dan Collucci, who posts here as ccharrison, sells it.

[Merg Ross]

Asher, Waterhouse stops with non-circular holes were used in making half-tone plates. The hole's shape is the dot's shape, the hole's orientation is the dot's orientation.

Yes they're called Waterhouse stops, after their inventor (?), John Waterhouse. You can read about him in your copy of the VM. If you don't have a copy of the VM, get one. Dan Collucci, who posts here as ccharrison, sells it.

Dan, thanks for the updated information. Filters were also used in place of the Waterhouse stops for making color separations.

[Asher Kelman]

Asher, Waterhouse stops with non-circular holes were used in making half-tone plates. The hole's shape is the dot's shape, the hole's orientation is the dot's orientation.

Yes they're called Waterhouse stops, after their inventor (?), John Waterhouse. You can read about him in your copy of the VM. If you don't have a copy of the VM, get one. Dan Collucci, who posts here as ccharrison, sells it.

Dan,

I appreciate your repeated help in getting me up to speed. I did check in the V. Mecum online, (no diagrams) on the Lens but couldn't find anything as helpful as the answers here.

Do you have any idea how the760mm f11 Apo Nikkor compares with the much, much heavier f9.0 Apo Germinar, besides the extra stop.

Asher

BTW, On a practical level, I'm considering mounting this 760mm Nikkor, which is light enough, on my Chamonix, (with the extended bellows and extension base). The huge 750mm f 9.0 Germinar is now mounted on a larger Toyo board for my camera obscura project. I have had SK Grimes sandwich a 5" Packard shutter #6 between two aluminum plates with a slip on adapter for all my barrel lenses. The front holds places for 6x6 filters. The shutter just arrived and I'm pleased as punch with Adam's work. Hopefully, it will not stress the front standard too much.

[Dan Fromm]

No idea at all, Asher, I've never had an Apo Germinar, know them only from reports by others. The reports are all very positive. You have both lenses, ask them.

That said, check the Rodenstock Process Lens Manual, which mentions but, as I read it, doesn't give mechanical data or MTF curves for six element Apo Ronars made "for especially demanding jobs." I expect they're better than the equivalent four element ones.

Dialyte type Apo Nikkors are in the same design family as four element Apo Ronars. By analogy, there are probably better process lenses, far off-axis if not on-axis.

My evaluations of lenses that cover formats larger than 2x3 reflect mainly on-axis performance, 'cos that's what matters most to me. I have yet to try a lens that's better than a dialyte type Apo-Nikkor of the same focal length centrally at f/9 and f/11. As good as, yes. Better than, no. But from f/16 down most of my process lenses of the same focal length are equally good on-axis.

[ic-racer]

Thanks ic-racer,

Yes, it goes from 0 to 90%.

So I gather these were some kind of plate with a pattern of multiple holes so soften the image perhaps? If so, do you know who might have such stops I could copy?

Were they actually called Waterhouse stops? There's a beautiful working aperture so I can't understand why a simple Waterhouse stop would be preferable to using the changeable aperture.

Asher

The first one is from a Nikon brochure. I suspect these are what you would want to copy. The second is from a Wollensak brochure.

Also, from the web:

the plates had square, or sometimes diamond-shaped apertures punched in them. This gave a more precise shape to the halftone dots that the lens had to reproduce for process platemaking.
In colour separation work, the screen orientation is rotated to a different angle for each of the four CMYK plates. The stop was also rotated to line up with the screen.

[Asher Kelman]

The first one is from a Nikon brochure. I suspect these are what you would want to copy. The second is from a Wollensak brochure.

Also, from the web:

Thanks ic-racer! good to have insight. Is there anything in the lens form which would not easily allow one to make a soft focus plate as in some of the barrel soft focus lenses so the center could be in sharp focus with a layer of light defocussed at the periphery. Just wondering. I'm happy with as sharp a lens as possible but it would be also fun to try to make a softening plate if that is feasible and there's a pattern to mimic.,

Asher

[Tin Can]

Excellent discusion I almost grasp at this time

Thank you all