Testing Enlarger Lenses

Wondering about performance testing Rodenstock vs. EL-Nikkors of the same/similar focal lengths. Wide open? 10x enlargement? Stopped down? Type of negative? Maybe some other optical arrangement. Have you done this? Seat of the pants, gut feel?

Thanks for your thoughts.

IMO, enlarging lenses from any of the top brands revealing similar optical characteristics will produce very similar images. I've never compared (or owned) the two brands you mentioned, but many years ago I did compare a 40mm Schneider HM APO with the 40mm Focotar lens that came with my V35 enlarger and found the Schneider to be quite a bit sharper at any of the enlarging sizes that I'd typically do (for me, about 8x.)

You might be able to find a test negative on Ebay, I've seen sets from time to time. I have a 35mm and 6X6 that we going to tossed by, I was in the Air Force and we got new set. Don't recall that we ever used them, I haven't used mine in years, when I last tested my Wollensake 50 and 75.

The question should be refined to whether being an academic or practical one.

Or with other words: If using a lens always stopped down, what significance then a test result at wide open should have? Unless one wants to focus at wide open.

I came into a large batch of lenses some years back. I decided to try printing the same negative with them with some materials that I wanted to use up. 23 lenses in all. They were many brands but all were 6 element or APO variants from Rodenstock, Schneider, Nikon and Fuji. The sharpness differences were hair splitting on 8X10 with the APO's depicting grain a bit more cleanly (just a bit at this enlargement size). One subtle thing that I noticed was the tonal depiction of very slight and light clouds in the negative. I literally hadn't noticed them initially but a couple of the Rodenstocks' (6 element Rodagons) prints showed them quite well. This sort of contrast difference was the biggest that I could depict. There wasn't a clinker in the group, which as the biggest surprise. FWIW, this was done on a well aligned (Versalign), stable enlarger (dichro) and Peak grain focuser so for my little quick test, I felt that I was isolating pretty much to lens difference. Perhaps some lenses would behave better under condenser light or cold light but I had enough proof to settle my curiosity. I kept the APO's and some old favorites along with the WA lenses. I have some ceiling height issues and the WA's have allowed some cropping that I would not have handled well, otherwise. If forced to grade sharpness, I'd say the German glass was best with the Fujinons EX's right in there with them and Nikkors perhaps lagging behind but only by a whisker. The APO's have seemed best at one stop down and this can lead to short exposure times as a slight irritation at times.

Danner said:

Wondering about performance testing Rodenstock vs. EL-Nikkors of the same/similar focal lengths. Wide open? 10x enlargement? Stopped down? Type of negative? Maybe some other optical arrangement. Have you done this? Seat of the pants, gut feel?

Thanks for your thoughts.

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The solidity and parallelism of your enlarger will matter more than the nominal performance difference - as will the carrier used. At 10x, you will struggle to tell apart modern first class enlarging lenses used on 35mm in a well controlled double-blind test. It's only once you get up towards 15-20x that the Apo lenses & specialist mural lenses start to come into their own.

23 lenses tested, all of the Double Gauss type... one of those projects.

Thank You!

But we should not overlook we often come across triplets too, either of the Tessar or even of the Cooke type.
The OP just said "Rodenstock".

Ctein published results of his testing of enlarging lenses in his Post Exposure book. The test includes most of the "usual suspect" lenses.
The PDF of the book is available on his website;
http://ctein.com/booksmpl.htm

OP Here:

My enlarger is a Saunders/LPL 670XL, owned since new, never rough handled, it's in excellent condition. I use the LPL glassless carriers of the correct format size.

The lenses at issue are:

50/2.8 EL Nikkor [35mm] (ca. 1971)
50/2.8 Rodagon [35mm] (ca. 1979)
75/4.0 EL Nikkor N [645] (ca. ????)
80/5.6 EL Nikkor [645/670] (ca. 1967)
90/4.5 Rogonar-S [670] (newer than 1998)

bdial said:

Ctein published results of his testing of enlarging lenses in his Post Exposure book. The test includes most of the "usual suspect" lenses.
The PDF of the book is available on his website;
http://ctein.com/booksmpl.htm

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Very nice, thank you!

East to do, any negative with grain will do. Use the aerial image of a Peak 200.

All my Nikkors, 90, 135, 150, and one Schneider 240 perform best two stops down, as far as sharpness goes. Always make all three planes has been levelled and aligned.

Andrew O'Neill said:

All my Nikkors, 90, 135, 150, and one Schneider 240 perform best two stops down, as far as sharpness goes. Always make all three planes has been levelled and aligned.

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And how about in the school darkroom?

At the highest magnification you'll use them at, and at the aperture you'll use for the largest printst?

I used Ctein's suggestion of a dot graphic material (the name escapes me at the moment) but it made it really easy to compare lenses as to sharpness, contrast and color fringing. What was most interesting was not in comparing different makes of the same length but in comparing different examples of the same lens. I ordered a bunch of lenses from 50 to 150mm off eBay and selected the best ones by test in each length and put the rest back on eBay. There were no dogs but just ended up with the cream of the crop. Hint, the old Nikor 50/2.8 is amazing.

MattKing said:

And how about in the school darkroom?

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I told them all to always close down lens two stops... or else! I can tell just by looking at their print if they didn't...

Superior resolution is only one desirable characteristic. Another is the ability to better differentiate subtle gradations of tonality in black and white printing, or resolve specific hues better when color printing. You pretty much get what you pay for, with the distinctly more expensive Apo versions from Rodenstock having an edge over the regular versions from all the "big four". Sometimes you can have too much of a good thing. I keep on hand both the contrastier Apo designs and regular ones for sake a less over-the-top look. For large format work only, I also use barrel process lenses like f/9 Apo Nikkors, which are better corrected and more acute than any official enlarging lens design. Another consideration is how even illumination you get at working f-stops, which is not always two stops down, though that's a good rule of thumb for most regular enlarging lenses.

Likewise, resolution test charts don't necessarily tell you what you need to know. Performance relative to color dye clouds needs to be taken into account if you are a color printer; and even in black and white printing, there are numerous variables which might differ from a test chart style negative. Real-world actual printing will tell you a lot more. But nothing will make sense unless everything about your enlarger setup is properly aligned and you're using a precise carrier with glass on both sides. Glassless carrier and you might as well be comparing Coke versus Pepsi bottles as enlarging lenses.

Thank you Drew, for the good information, For me, it's all B&W. I'm going to find suitably dense and sharp negatives and do some 11x14 prints (or sections thereof) at about f8. After reading some other resources, I'm thinking all my lenses are plenty good stopped down a bit, and as long as I do my part.

I'm not sure about aligning the enlarger, I don't see any adjustments on the thing? It all looks square and true to me.

Danner said:

I'm not sure about aligning the enlarger, I don't see any adjustments on the thing? It all looks square and true to me.

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I've not had your model of enlarger but I'm certain there are shimming areas that can get it in true alignment. Film stage to lens stage to easel. You will be surprised at how good alignment can remove an important variable in your process. I'm plagued with Beseler (MXT, XL and 23's) gear which has the fit of a door on a '63 Dodge Polara, which is to say, not the best but they seem to hold their alignment quite well. Your LPL is more precise but wear and gravity take their toll.....

Danner said:

I'm not sure about aligning the enlarger, I don't see any adjustments on the thing? It all looks square and true to me.

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Our naked Apug fellow has made some videos on this matter, they might give you an idea:
https://www.youtube.com/channel/UCUcaft-3hNIuB1L1IgARPoQ/videos

The LPL/ Jobo/ Saunders enlargers are designed to be accurately and permanently aligned from when they are assembled - except they aren't always so, nor do they always remain so, and they don't really have alignment adjustments in the manner of De Vere etc.

AgX said:

Our naked Apug fellow has made some videos on this matter, they might give you an idea:
https://www.youtube.com/channel/UCUcaft-3hNIuB1L1IgARPoQ/videos

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Wow! That is a good YouTube channel, subscribed.

I used several 50mm El-Nikkor 50mm f/2.8 lenses over five decades. They were consistently good. Illumination became even at f/4. Maximum sharpness was at f/4 and f/5.6. Diffraction limited sharpness at f/8 and smaller apertures. Enlargers used were mostly an Omega B-22 and an ancient 4.5 DeJur Versatile Professional, both with glassless negative holders. Glassless carriers are not necessary for 35mm negatives stored perfectly flat and used in moderate humidity.

Danner said:

Wondering about performance testing Rodenstock vs. EL-Nikkors of the same/similar focal lengths. Wide open? 10x enlargement? Stopped down? Type of negative? Maybe some other optical arrangement. Have you done this? Seat of the pants, gut feel?

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Over the past 30 years, I'm pretty sure I've used just about every lens in the medium format range (80mm-105mm) from Nikkor, Rodenstock and Scheneider. I've never done side by side tests with them but I never had any indication that one was better than the other. I finally kept a full range of Nikkors from 50mm to 150mm and sold the rest.

I like using old lenses. Just because I could, I tested my 1958 Leitz Focotar 50mm f/4.5 (a 5-element Triplet for this version as I recall) against my 1954 50mm f/4.5 Kodak Enlarging Ektar (a 5-element Heliar). Both lenses were stopped down to f/11 (the Kodak published sweet spot for the Ektar) and installed them in my Omega D-II with a 35mm negative enlarged to 8x10 (about 7x enlargement if my math is correct). To my non-scientific, highly subjective assessment, I felt the Ektar was sharper in the "in-focus" areas of the print but the Focotar rendered the bokeh better. That might be surprising to some and others may come to a different subjective assessment using this exact equipment. It is important to say that both prints were highly acceptable. Without knowing which lens printed which picture, I doubt all but the most observant expert could tell the difference. In short, if you had either of these lenses, your results would be very, very good.

A more interesting test however was Ansel Adams flare test mentioned in "The Print". Adams indicated that coated lenses were superior to uncoated lenses for their reduction of flare. I'm fairly certain most (all?) decent lenses today are coated and this test is moot. However, his test did demonstrate one fact about using lenses wide-open. I used his test of punching a sharp hole in a piece of cardboard and exposing a scrap of paper for 5s and processed it normally. I employed my 1944 uncoated 100mm f/4.5 Kodak Enlarging Ektar and a 1947 coated Ektar of the same type. Wide open (f/4.5), both lenses created significant flare that spread noticeably outside the image of the sharp punched circle. Stopped down (f/11), flare was very well controlled in both lenses. The coated lens (obviously?) won out on the test...but just barely. For most enlargements, I'd say it would be hard to tell the difference which lens was used.. It may be a more significant factor in high contrast imagery or enlargements than 10x or so but I didn't test to those conditions. What the test did effectively demonstrate was that wide-open one can expect flare to be less controlled in any lens and could expect a potential impact on the separation of tonal values.

My humble opinion therefore is: If you're getting prints you like, you're equipment is not just satisfactory - it's great. If you think you could do better, make a controlled adjustment or try another lens. Would I get better results if I switched to a modern Gauss/APO lens, who knows? I'm very satisfied with the prints I get. The posts here by persons far more experienced than I suggest that most decent quality equipment will provide nearly indistinguishable results. Therefore, unless you need a lens that performs in a superior manner for a precise type of work or conditions or you like the satisfaction that test data provides you, you'll likely be chasing perfection that may not be achievable.