Rodenstock Apo-Gerogon Lenses

i have 150mm and 240mm apo gerogon lenses. Does 1:9 mean f9? Where can i find the aperture size for th waterhouse stops?

Thankyou.

Bip.

Yes you are correct the 1:9 means f9.

To answer your other question, it's not going to be easy but at least you got some choices. Try on Ebay, slow could take time but you can get lucky too. Friend in the right place could manufacture those to you and finally you can contact Linos who owns the Rodenstock nowadays and ask Sabine who is a sales manager if they got anything left. Contact me for her email address.

I forgot to mention that you can ask them for the sizes if you want to manufacture those by yourself and it's also possible for you to count it out those by yourself

The other of my earlier suggestions was to try to buy a complete set.

Um, Bip, don't your Apo Gerogons have diaphragms? I ask as I've had a couple and all of them had diaphragms.

The 150mm F9 Rodenstock Apo-Gerogon here has a diaphram.

My Apo-Gerogons, like every other repro lens that I own, have both an iris and a slot for Waterhouse stops. The iris scale is marked in both relative aperture, from f/9 to f/90 if I remember correctly, and in actual diameter in millimetres.

 

And yes, 1:9 means f/9. Although if you use these lenses at their intended magnification, then you'll have to work out the effective aperture from the formula; (1+m)* marked aperture number = effective aperture.

 

The Waterhouse slot is there so that square or diamond-shaped apertures could be used, in order to get better dot definition when using half-tone screens.

RJ, I think that the slot for Waterhouse stops may be a sometime thing. I just dug out the one Apo Gerogon I now own, 210/9 s/n 8 785 288. It has a normal aperture, stops f/9 to f/64, and no slot.

 

Without doing a lot of research, I don't think that all G-Clarons have slots either. IIRC, the 150/9 plasmat type that I no longer own didn't have have and neither did the three dagor type 240/9s that I've long since sold. But since my memory is failing I could be mistaken about them.

 

Thinking of repro lenses, how do you classify TTH's "Taylor Hobson Copying" and "Cook Copying" lenses? I ask because these f/9 tessar type lenses seem to be, as the VM suggests, Apotals in much simpler lighter mounts. The one Apotal I own, a 30 cm/9, is surely a process lens and has the slot. My TTH copying lenses, a 6"/9 Cooke and a 10.16"/8 Taylor Hobson, don't.

 

Also, how would you classify the Boyer Beryl? I ask because I have a 210/6.8, extracted from a Gestetner copy machine, that has no slot and a 210/7.7 Beryl S, made for some reprographics application or other, that also has no slot. I've borrowed a 210/6.8 Emeraude that turned out to be a normal ordinary f/6.8 Beryl sold as a reprographic lens; its barrel had a slot.

 

D'ye think that perhaps lenses made for vertical copy cameras usually lack the slots and those made for horizontal usually do?

 

I have a small heap of Waterhouse stops that came with Apo Saphirs and Apo Nikkors. All have small circular holes. Any idea what they're used for?

 

Cheers,

 

Dan

Thank you for your responses. There is no diaphragm on the repro lenses I have.

I have a few waterhouse stops so probably not a complete set. I will experiment or find out from Rodenstock what the apertures are. I bought them because they were very inexpensive and just lookiong forward to producing some interesting close up photographs with them.

Many thanks.

Bip.

The equation for aperture diameter is aperture diameter = focal length divided by f-number. The only trick to this is that the aperture diameter is supposed to be measured through the lens, as seen by the subject. But this is normally only a very small correction factor to the simple equation. Since you have some of the Waterhouse stops, you can measure their diameters and deduce their f-numbers. You can them make more using the equation to calculate additional aperture diameters. Or, another way to approach making more: for a whole f-stop sequence, the diameters will vary by factors of the square root of two, to make the areas vary by a factor of two.

Hmmm. No idea why anyone would want to use circular fixed stops when the iris fitted to most post-war repro lenses has 13 blades or so, and stops down to around one millimetre diameter. As I said before, the main reason for the slot, at least in half-tone separation work, was to fit odd shaped apertures for special purposes. Presumably the fixed circular apertures were made purely for the sake of convenience and repeatability.

 

Some of the TT-H Cooke Apotal lens used special glass which was radioactive. However I have two samples of Apotal, both fitted with slot and iris, one of which is "hot", while the other isn't. My one sample of Apo Nikkor also has the slot and iris arrangement.

 

I guess it depended on the intended use, whether slot, iris, or both were fitted.

 

I think all of the lenses I've mentioned are Apo-Tessar designs, although an Aviar type design was also widely used in repro lenses. The Repro-Claron is an Aviar type.

 

I wouldn't class G-clarons as reprographic lenses, since they're double plasmat designs. They're more of a general-purpose copying lens. That's why they don't stop down very far, and don't usually have a waterhouse slot.

 

Purely by the by. I've toyed with the idea of using the waterhouse stop facility as a soft-focus device. The idea is to drill numerous very small holes in the stop-plate. The holes should be individually small enough to severely limit resolution through diffraction, but sufficient in number to allow a useable amount of light through. However, I've watched professional engineers being driven to distraction drilling numerous sub-millimetre holes in metal plates. So I don't relish doing the task just by way of an experiment!

<p>Which pitch has the M50 thread of apo-gerogon 210/9? if only M50 is mentioned then is it always x1?</p>

M50 x 0.75.

 

See my answer to your question in the other forum. By the way, this is a wide angle process lens made for vertical

process cameras, like a Kenro. It makes a terrible enlarging lens and is not a general purpose taking lens. It is an

excellent flat field copy lens at 1:1 or close to 1:1. It was designed to deliver optimal performance at f22.

<p>Thanks a lot. I thought it since i have digged out schneider componon-S-data. all lenses from 135 to 300 have M55 to M77 threads all with .75 pitch.<br>

rodagon G 105 and 150 both have M50 but no pitch defined in the list of prograf.ru<br>

i understand that pitch is not changed for small mount to fit shutters.<br>

what the biggest shutters mount? i have copal1. will use the lens with rsp-M39x1 adapter on copal-1 with M39X1 adapter. plus a combination with minimacro-helicoid by zoerk. we will see if i can work with it or a different helicoid is better<br>

so now how are the thread-versions defined correctly? maybe you already answered in largeformat-forum.<br>

M67 X0.75 is male<br>

M67 F.75 is female correct?<br>

Bob are you from B+H or catlabs?<br>

i once have found a lens list with data in a forum but dont know anymore. google is blind.<br>

i am trying to get a prospectus from ebay</p>

No, I was with the USA Rodenstock distributor. You were looking at a Russian distributor site. Not the Rodenstock factory

web site.

<p>still have problems finding specifications, all threads of apo-gerogons, g-clarons. aswered also in largeformatphotography and opened a thread in lounge.</p>

Rodenstock only lists the filter had size and the rear flange size, which we have told you is M50 x 0.75. If you are looking

for the thread size of the rear of the front group and the front of the rear group then Rodenstock does not list those and

they are not 0 or 1 size shutter threads. As I mentioned earlier, if you want to properly mount the cells into a shutter you

will have to take the lens andtheshutter to a machinist to have them mated properly in the shutter

<p>the files you provided in dl-site did not show any size for apo-gerogons. technical description but no technical data. i have seen one file which does not show it.</p>