50mm f/5.6 Rodagon

[mdarnton]

I just picked up an enlarger with a lens I've never heard of before, a 50mm f/5.6 Rodagon. I find very few references to it on the web, and they refer to it as some sort of revolutionary Plasmat design from the 70s or 80s. Does anyone know anything about this one?

I just brought it home, so I haven't had a chance to do anything with it. Eventually I'll be able to test it in a darkroom I'm making, but for the time being all I'll be able to do with it is to try it for duping negatives...

[Himself]

Load up a picture with the culprit.

[mdarnton]

The most interesting thing to me is how tiny the glass is, and how round:

[ForenSeil]

[Orio]

One positive aspect of enlarging lenses when used for duplication is that they are built to be focused wide open and operated stopped down,
meaning they (the good ones) have no focus shift.
Which is what you also want when duplicating (being able to focus wide open and stop down for shooting).

[mdarnton]

Well, I don't know how it is as an enlarger lens, but I did try it today in my negative copying setup, and it lost. Like all of the 50mm enlarger lenses I've tried in this job, which is done at about 1:2, it was grossly inferior to any of my three micro-Nikkors, all of which do an equally stellar job, in spite of being from three different periods (one early non-ai 55/3.5, one a late 55/3.5 ai, and the third a 60/2.8 af-d).

So far all of the enlarging lenses are grossly inadequate next to any of the micro-Nikkors. The thing that has surprised me the most is that in this application I can't tell the Nikkors apart. They're supposed to be among the best lenses Nikon has ever made, and they're demonstrating that. They all have higher contrast than the enlarging lens and all are obviously resolving more than my camera can use, right out to the corners. I only use the earliest lens in the copy rig because it's the lens for which I have the least affection--I use the ai and af-d in my studio on real stuff.

Now I'm starting to wonder how the micro-Nikkors would work as enlarging lenses! Maybe I can rig up one of my scrap Nikon bodies as an enlarger, Graflarger style: http://graflex.org/speed-graphic/graflarger.html

[Orio]

[ForenSeil]

[mdarnton]

What is "neutral" anyway? I don't think it's possible for a lens to actually increase the contrast of anything, since it's merely a transmission device, so I figure in any pair the one with less contrast has a transmission defect, and is not better. Neutral is what I see, and enlarging lenses give me less than that.

What I thought was interesting about the micro-Nikkors was that Bjorn Rorslett has definite opinions about them, and those opinions were NOT supported by my tests. I always find peoples' photo tests suspect, anyway; for instance when anyone posts 800x600 images to prove a lens is good, or pictures of flowers, proving the center is OK, but how about the edges? Peoples' tests are so non-test-like. But trying to image the grain of a flat negative from corner to corner--that's more like a real test.

In testing enlarging lenses for this, of the more interesting results was that my clean new version 50/2.8 El-Nikkor got pounded in every respect by an El-Omicron 50/2.8 with fungus around the edges (but otherwise clean). An ancient, not particularly clean-inside 50/4 Componon was meh. I guess they're just not up to 1:2, basically.

[martinsmith99]

[ForenSeil]

I think there are several different 50/2.8 El-Nikkors bye the way. I also had one in very good condition and was a little disappointed when I compared it with my Rodagon which was a lot better espececially below 5.6. But otherwise I heard other people saying that the Nikkor is better or at least in par.

[mdarnton]

Yes, the last one with a lot of plastic is supposed to be the best one. I'm not thinking this is a lens problem as much as it's inappropriate usage.

[Orio]