Age of 240mm Apo Rodenstock f5.6 Lens. (MC?)

[neil poulsen]

I just purchased and received a Rodenstock 240mm Apo-Rodegon f5.6 lens. It's huge! The seller indicated in the listing that this lens is multi-coated. But, it's not multi-coated as was stated in the listing. The serial number is in the 6,601,XXX range, and from Kerry's website, it can't date past 1971 and more likely in the late 1960's. Rodenstock began multi-coating their lenses in the late 70's.

How might this len's performance compare to a multi-coated version, given that it's also an Apo enlarging lens? Would one really see a difference?

[Allen in Montreal]

Neil,

Some of my older Rodagons seem sharper and nicer in B+W than some of the newer ones. I regret trading my old 180!
What do you want to do with the lens?

[Bob Salomon]

Neil, all Apo Rodagon lenses longer the 180mm were process lenses not enlarging lenses. A Rodagon will be a far better performer as it was made to make small things like negatives into large things like enlargements. The Apo Rodagon process lenses were made to make 1:1 reproductions, not enlargements. It is also optimized to only perform optimally at f22 and your enlarger probably does not have enough light to work at f22 in a reasonable time.
Your serial number is from 1970.

[Drew Wiley]

Although I own quite a few enlarging lenses, that ordinary 180 Rodagon which
didn't cost a bundle in the first place is one of my favorites.

[neil poulsen]

Curious.

According to the Rodenstock website, the recommended scale of a current Apo-Rodagon-D f5.6 120mm lens is 0.5x to 3x and the optimum f-stop is f5.6 to f8. Correspondingly, the recommended scale of the Apo-Rodagon D 75mm f4.5 is 1.2x to 2.5x. I recognize this is anecdotal. But it's interesting to see that as the focal length increases the recommended scale also increases.

I'm wondering, there's this lever just below the aperture ring that extends from about f16 on the aperture ring to the same distance or a little longer beyond f128. I turn it, and it doesn't seem to have any effect on the lens, the aperture, etc. What's this lever for?

[Phil Hudson]

I seem to recall that there is a slot for waterhouse stops on these older long Apo-Rodagon lenses - maybe the lever you see is just a blanking cover for the slot when it is not being used?

[Bob Salomon]

Curious.

According to the Rodenstock website, the recommended scale of a current Apo-Rodagon-D f5.6 120mm lens is 0.5x to 3x and the optimum f-stop is f5.6 to f8. Correspondingly, the recommended scale of the Apo-Rodagon D 75mm f4.5 is 1.2x to 2.5x. I recognize this is anecdotal. But it's interesting to see that as the focal length increases the recommended scale also increases.

I'm wondering, there's this lever just below the aperture ring that extends from about f16 on the aperture ring to the same distance or a little longer beyond f128. I turn it, and it doesn't seem to have any effect on the lens, the aperture, etc. What's this lever for?

That is the slot for Waterhouse filters. Again, this is a characteristic of a process lens to control the dot pattern in the repro negs.

There is also the Apo Rodagon D 75mm f4 for 1:1 copying (these are slide duplicating lenses, not process lenses and not enlarging lenses.)

[neil poulsen]

Phil, I think that you're right. Pushing this lever to the left reveals an opening just under the aperture. Why would a lens with an aperture from f5.6 to f128 also have Waterhouse stops? Thanks for your comment.

As a question, why would a lens equipped with an aperture from f5.6 to f128 use Waterhouse stops?

[neil poulsen]

Allen, I was planning on using this lens on a Zone VI Type II 8x10 VC enlarger. It has a lens board large enough to handle this lens.

[Phil Hudson]

I have never used the Apo-Rodagons as a process lens but my 300/5.6 Apo-Rodagon came with waterhouse stops (for f/16 I think). Perhaps others can chime in here but I think it might have been quicker and more accurate to use waterhouse stops on a copy camera than setting the aperture by eye from the engraved scales.

I presume that the supplied f/16 stops means that this is the optimum aperture for my 300mm lens? Can't think why else it would have been supplied considering that exposure time and light intensity can be varied to achieve whichever aperture is desired.

[Joerg Krusche]

Hi,

Bob is right .. the Apo Rodagons were made to offer a larger field and one f-stop less for a brighter image/shorter exposure time as compared to the Apo Ronars .. they were more expensive and came in 240/300/360 mm .. I once played with a 240 .. shot with it on a SL 66 at f 11/16 .. using the center on my MF .. images were sharp .. I mean really sharp .. while f=5,6 was very soft .. just for focussing .. nice for portraits .. but stopped down totally changed character .. so much about possible "abuse" of these Apo Rodagons.

Joerg

[Joerg Krusche]

Allen and Drew,

I share your view on "standard" Rodagons .. I recently made a test using the USAF 1951 chart on my L1200 .. to my amazement these lenses had no problem to resolve that bar pattern of the test chart that represents a little more than 11 000 dpi or about 230 line pairs per millimetre .. lp/mm .. I saw it on the micro focus finder .. could not believe it ..asked myself whether this was real resolution .. whether it could be printed on paper .. i.e. group 7 with elements 5/6.. it was possible using an ordinary rodagon .. at f 2,8 .. we may never need that resolving power .. and with stopping down resolution will go down anyway.. this just to give an idea of the potential of a "simple" enlarging lens .. no scanner can get anywhere near that .. these lenses are diffraction limited .. and not only at f 22/36 !!

Joerg

[Oren Grad]

As a question, why would a lens equipped with an aperture from f5.6 to f128 use Waterhouse stops?

Bob just answered that, but here's a more detailed explanation:

http://www.largeformatphotography.info/forum/showthread.php?t=6535

[Chuck Pere]

I use this for my enlarging lens. Mostly 5x7 negatives and 4x5 with an occasional 8x10. And only small enlargements as I have a 210 Rodagon I use for bigger size prints (4x5 and 5x7). I mainly use the 210 as it makes reaching the focusing knob much easier. I bought my lens during a Calumet sell-off in the 80's. It's serial number is 9429xxx. I also have data sheets on these lenses from 1974/75. Best at 1:1 with use between 1:3 and 3:1. Recommend working aperture is f16. If anyone wants a copy I can scan these into a PDF file. If interested PM me.

[neil poulsen]

I use this for my enlarging lens. Mostly 5x7 negatives and 4x5 with an occasional 8x10. And only small enlargements as I have a 210 Rodagon I use for bigger size prints (4x5 and 5x7). I mainly use the 210 as it makes reaching the focusing knob much easier. I bought my lens during a Calumet sell-off in the 80's. It's serial number is 9429xxx. I also have data sheets on these lenses from 1974/75. Best at 1:1 with use between 1:3 and 3:1. Recommend working aperture is f16. If anyone wants a copy I can scan these into a PDF file. If interested PM me.

Thanks for your input. This is interesting information.

In it's optimum scale (1:3 to 3:1), how does the 240mm Apo Rodenstock compare to other enlarging lenses that you've tried? How do you think that it works for 8x10? Also, how far can you vary from f16 before seeing a decline in performance? At what apertures do you typically use this lens?

[Chuck Pere]

I've never really done any formal testing. This one has always seemed very sharp to me but you probably don't need much of a lens for these small enlargements. When the negative is sharp things look sharp and contrasty. For the limited number of 8x10's I've tried no problems either. I've used mainly f11 to f22 depending on paper speed. Some times f8 for the old slow Forte. I like to shoot for f16 if I can. I'll add that my enlarger is an Elwood so maybe not the precision machine of a newer Durst. That is probably more of a factor than the lens.