Mystery 150mm Apo Rodagon N

[Richard Wasserman]

I have a 150mm Apo Rodagon-N lens that is much larger than a regular enlarging lens and has no adjustable aperture. I am wondering if with Waterhouse stops this could be used as a 4x5 enlarging lens? Also I am curious what it might have been originally designed for—process lens of some sort? I unfortunately can't post a photo at the moment as my digital camera is not feeling well. The lens has a 75mm diameter front element and about a 72mm mounting thread. The overall length is about 96mm. Any ideas????

[Daniel Stone]

does it have a slot for waterhouse stops?

I seem to remember reading about some "minilab" machine that was able to print from 5" aerial rollfilm negatives, and it might have used one of these. IDK though. I've never seen the aforementioned machine, not even a picture of one, just a reference or two over the past 2 years worth of internet reading. Since it was designed for high-output printing, I'd imagine it'd be easier to adjust the light output to compensate for negative density, and in turn, final print(or to receiver positive film).

IDK though...

-Dan

[John Schneider]

There was a guy who was selling lots of these lenses on ebay 4-5 years ago. I always passed because of the lack of an iris. I don't remember if his auctions explained the original purpose of the lenses

[Bob Salomon]

The Apo Rodagon was used as an intregal part on an OEM basis for many things. For instance, they were used to scan envelopes at the US Post Office sorting stations to read the bar code/Zip Codes on the envelopes and mail pieces as they sped down the line.
Many lenses, like those at the PO were optimized for a specific magnification and had no adjustable aperture ring, no dis-engagable click stop lever, no pre-set aperture mechanism and no illuminated aperture. All basic parts of a Rodenstock enlarging lens.

So you have a salvaged part from a machine. It may have been a package printer for making a set size print from a specific size negative. It may have been from a machine vision system for examining parts on an assembly line to see if the part, or maybe the orange/apple or lemon, were of acceptable size, quality/finish or it may have been part of a scanner as used by the PO or one from graphic arts.

[Richard Wasserman]

Thanks Bob, I thought it was something like you described. It is obviously a very different lens than an Apo Rodagon-N enlarging lens. Why the same designation? I guess I'll stick it on my enlarger and see how it performs (it does seem to focus correctly), and then decide how to proceed.

[Bob Salomon]

Thanks Bob, I thought it was something like you described. It is obviously a very different lens than an Apo Rodagon-N enlarging lens. Why the same designation? I guess I'll stick it on my enlarger and see how it performs (it does seem to focus correctly), and then decide how to proceed.

Because it is an Apo Rodagon-N. Just made for a different purpose.

[Richard Wasserman]

Of course—it's the lens formula, not the application. Thanks!

Because it is an Apo Rodagon-N. Just made for a different purpose.

[Arne Croell]

Of course—it's the lens formula, not the application. Thanks!

Although its not impossible that they tweaked the lens radii and/or glass types for specific applications, I would guess it is made with the same lens elements as the regular enlarging ones, just without the aperture - one possible change might be the spacing of the back and front cells.

[Richard Wasserman]

Arne,

The lens I have is physically larger than an Apo Rodagon-N enlarging lens, both in diameter and length.

Although its not impossible that they tweaked the lens radii and/or glass types for specific applications, I would guess it is made with the same lens elements as the regular enlarging ones, just without the aperture - one possible change might be the spacing of the back and front cells.

[Arne Croell]

Arne,

The lens I have is physically larger than an Apo Rodagon-N enlarging lens, both in diameter and length.

Yes, I saw the larger diameter in the original post, 75mm vs. 70mm for the enlarging version. The question is, is it just the housing or are the lens elements also bigger?