610mm Apo Nikkor F9 Lens Question

[Tom Taylor]

Does anyone know what the lever (above the aperture ring in the photo) is for? It rotates from below the zero mark on the top scale to past the 90 mark but no movement in the lens can be detected.

Thanks,

Thomas

 

[richard ide]

It is to operate a cover for the slot you see. Open; one can insert Waterhouse stops which are metal plates with holes in them which are used instead of the iris diaphragm. At one time, particularly in the graphic arts (printing) industry; an aperature with a modified hole shape was an aid in producing halftone negatives with dot shapes other than round or square.

 

[ic-racer]

If you are going to use that lens on a camera, you might get more benefit from the waterhouse slot if you could fabricate (or find) the Wratten filter holders that fit in the slot.

 

[Tom Taylor]

Thanks Richard. That was a puzzle to me.

Could you please elaborate on that ic-racer? How would using a waterhouse stop be an improvement over the iris?

Thanks,

Thomas

 

[Regular Rod]

Thanks Richard. That was a puzzle to me.

Could you please elaborate on that ic-racer? How would using a waterhouse stop be an improvement over the iris?

Thanks,

Thomas

Might it really be for inserting filters?


RR

 

[DREW WILEY]

There was a little flat plate (I've got one laying around somewhere), and they'd put a red gel filter in it. Acted like a safelight when they were
using ortho graphics films. I'm not implying that was the only use for that slot. If three or four-color separations were being made, other
deep gels could be used. And the waterhouse option. But there were also specialized versions of these which have not only the typical multi
bladed aperture, but a second aperture which produced an adjustable square hole!

 

[ic-racer]

Could you please elaborate on that ic-racer?

The filter holders are shown on page 10 here: http://savazzi.freehostia.com/download/manuals/Apo Nikkor 1.pdf

 

[Vaughn]

...Could you please elaborate on that ic-racer? How would using a waterhouse stop be an improvement over the iris?

Thanks,

Thomas

A perfectly round hole gives a slightly different out-of-focus look than a not-round hole created by the iris blades?

 

[DREW WILEY]

These waterhouse goodies were related to the reproduction of halftone dots, which needed to be crisp and might have been slightly affected
otherwise at different magnification ratios. You'd have to talk to someone from back in the traditional printing industry days, unless someone
here has that background. I use these lenses in the darkroom, though it would be nice to have shutters for a few of them too, for view camera use. They're optically marvelous. The multi-bladed apertures are wonderful too, but don't expect a pleasant "bokeh" from these tack sharp lenses - it's more the double-lined effect. I've contemplated how to screw-up the optics with some kind of softening diffuser in one of those little inserts, just for the fun of it. I'm not really a soft-focus type, however.

 

[Tom Taylor]

Thanks for the replies everyone and especially is-racer for posting the link which raises the question of whether or not I should tape-up the slot?:

“When no plate is installed in the lens the slot should be closed (a lever is provided for this purpose) to prevent the entry of contaminants into the interior of the lens.”

Thomas

 

[E. von Hoegh]

Thanks for the replies everyone and especially is-racer for posting the link which raises the question of whether or not I should tape-up the slot?:

“When no plate is installed in the lens the slot should be closed (a lever is provided for this purpose) to prevent the entry of contaminants into the interior of the lens.”

Thomas

If you look at the slot the lever moves in, you will see that moving it one way opens a slot to the interior of the lens. Leave the lever in the position which closes the slot, as per your quote above.

 

[Tom Taylor]

If you look at the slot the lever moves in, you will see that moving it one way opens a slot to the interior of the lens. Leave the lever in the position which closes the slot, as per your quote above.

Thanks!

I sent it off to Grimes this morning to have it mounted on a Toyo board - can't wait to get it back and use it. I have some images already planned with it.

Thomas