apo lens for enlarging

If you take 6 lenses straight off the production line and compare their performance they won't all be equal. One or two are likely to be better than the others.

So whether you get a good one or an average one is wholly dependant on the quality control standards. They have margins of error which they consider acceptable.

I used to own a Rodenstock 150 APO N. It was a good lens but I would suggest that it was no better than a straight Rodagon 150 at normal enlargemnet sizes. Both are optimised for 6X enlargement but the APO has a manufacturers scale of 2X-15X whereas the the non APO scale was 2X-10X.

The APO should always win over the non APO if you go above 6X enlargement factor. Upto that I doubt you can tell the difference with B+W. You may be able to with colour but I don't know since I never tried.

Schneider have never published their optimums online or rather I have never found them. But they do publish it in the little booklet that comes with each new lens if you happen to have one of those.

So any test of one individual lens against another lens of another brand proves exactly nothing except that one of those two specific lenses is better, the same or worse than the other. It doesn't prove that all lenses of that specific model are better than all lenses of the other model.
You need to do the test with a batch of each to get a more generalised view of which is better and my bet is that no one is going to do that.

Just for those interested, there was a later (final) series of Apo Rodagon N's that are rarely seen: the 45mm, 75mm and 90mm. (note, there was an Apo Rodagon 90mm non-N, which is an earlier and lesser caliber lens). These replaced the 50mm and 80mm apo rodagon Ns; the 105mm -N and 150mm -N continued with this "final" series to form the lineup. The 45mm was the only 8-element lens of the group, the rest were 7-elements. I have literature on some of these, if I haven't posted it online I can (some comes courtesy of Bob Salmon).

Agree with Drew though that the Apo El Nikkors were/are the gold standard of enlarging lenses.

EdSawyer said:

...the Apo El Nikkors were/are the gold standard of enlarging lenses.

Click to expand...

Got a 170mm version you'd like to sell me?

There was a 105 Apo EL recommended for 35mm and 210 for up to 4x5. I have the brochures at home. Remember, these recommendations
were for repro standards which exceed general darkroom printing use. Same with the Apo Nikkor series. These two Apo EL's have skyrocketed in price due to their use on scanning cameras for forensic and high-end painting copies etc. Focal lengths longer than these have always been rare and extremely expensive. The last 360 Apo El that I'm aware of being sold went for 11K. Pretty extreme when you can get a superb 360 Apo Nikkor for two or three hundred bucks. Most enlargers won't even hold the weight of some of those Apo EL's. My ordinary 3605.6 EL Nikkor (non-Apo) must be five times the size of my 360 Apo and needed a custom size board and bellows. But it's really
nice to have the extra focus brightness for composing thru the orange mask of 8x10 color neg film, esp if any supplementary masking density is in place. With Cibachrome I needed the speed, period. I gave up on high-wattage light sources. Too much heat and enlarger
maintenance.