Some questions and thoughs about my enlarger lenses

Hello!

Recently I've been checking my enlargers alignment.

What I observed was that all four corners had the same focus level and it was different from that of the center.
Then, by focusing on the center of the image, I checked the corners and observe as I stop the lens down. Here, I found something interesting. I found the different lenses behave differently.
For example:
My Rodagon 80mm f/5.6 had blurred corners and they became sharp when I step down to f/8-11
My El-Nikkor 50mm f/4 had also blurred corners but they became sharp at about f/11
Unlikely, the El-Nikkor 50mm f/2.8 had very sharp corners even wide open at f/2.8.
Finally, one Schneider Componar 105mm f/4.5 had to be stopped down to f/16 to have acceptable sharp corners.

I know that the El-Nikkor 50 and the Rodagon 80 are both 6 element lenses so high quality is expected. Also, Nikkor 50/4 has 4 elements and the Componar has 3.

Now, my questions are:

Is it normal that the Rodagon has not sharp corners like Nikkor 50/2.8? Could that mean a default on my lens?
Also, I noticed a difference in the detail I could see between the Nikkor 50/2.8 and the Rodagon. The negative was the same. Is that ok?

Please note that all the observations were made with a grain focuser, but I plan to do some tests on paper too. Also, the Nikkors are in mint condition, the 2.8 is never used, according to the seller. The 50/4 makes a sound when I shake it, could that be an element that is loose? The Rodagon is used, but it is very good condition, its optics are clean and clear.

Could you help me identify what is the version of the lenses I have?
Is my Nikkor 50/2.8 N or not? It hasn't the same design as the Nikkor 50/4.
And the Rodagon has a rubber aperture ring and a red strip. (I can provide pictures and serials numbers if they can help)

Thank you for your repsonses and your attention,
George

P.S.: Is there any site that I can see the technical specifications of enlarging lenses? From what I searched I found a Rodenstock's pdf file that has some information about its newer lenses. Can these specifications apply to my Rodagon?

Is your testing being done with glass carriers and a leveled enlarger?

I was getting results like that with my enlarger lenses, but it was the film slightly sagging in the holder. Try using a glass carrier and compare. My EL-Nikkor 50mm f/4 is incredibly sharp on the entire frame @f/8. My Comparon 75mm (I know, not a componon... but it's optimized for the 8x10-11x14 range, and I couldn't tell a difference between it more expensive lenses at an 8x10) is also ideal at about f/8, except with Foma film, which needs f/16 because it's so curly and won't stay flat like FP4 and Acros do.

@Bob Carnie: Yes my carrier has glass and my enlarger is leveled.

@fretlessdavis: For the Nikkor 50/4 the sharpness was good at f/8 but in my eyes I had to go to f/11 for calling it sharp corners. As I reply to Bob, I use a glass carrier, so I guess film flatness is not an issue

Noticed your comment about the 50/4 making noise while shaking-- Mine does not. There's probably some variation between the two, and maybe some issues if it's making noise, but I definitely have great sharpness corner to corner @f/8 after checking prints under magnification. The others sound pretty typical to me in their behavior, after testing out pretty much a whole case of enlarger lenses. 2 stops down from wide open is a good starting place for most good, but not necessarily new, EL lenses. Having to stop why down on a Componar is typical, and 1-2 stops on a Rodagon seems pretty reasonable.

EDIT: The 5.6 Rodagon 80 is an older one in the Rodagon series-- quite nice lens, but stopping down 2 stops is definitely par for the course (for older nice lenses) to get good corners. Just like older Componons-- definitely wouldn't expect to be able to use them wide open.

fretlessdavis said:

Noticed your comment about the 50/4 making noise while shaking-- Mine does not. There's probably some variation between the two, and maybe some issues if it's making noise, but I definitely have great sharpness corner to corner @f/8 after checking prints under magnification. The others sound pretty typical to me in their behavior, after testing out pretty much a whole case of enlarger lenses. 2 stops down from wide open is a good starting place for most good, but not necessarily new, EL lenses. Having to stop why down on a Componar is typical, and 1-2 stops on a Rodagon seems pretty reasonable.

EDIT: The 5.6 Rodagon 80 is an older one in the Rodagon series-- quite nice lens, but stopping down 2 stops is definitely par for the course (for older nice lenses) to get good corners. Just like older Componons-- definitely wouldn't expect to be able to use them wide open.

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From any prints I had with the Nikkor 50/4 there was nothing to make me worry. But I have never made prints to check the performance of my lenses.

So you think the Rodagon is fine? With the Rodagon I had some prints used wide open -mainly when making test strips- and I noticed a very obvious difference in detail. Much better performance when stopped down 2 stops.

Yeah, your Rodagon sounds fine to me! Unless you're pushing past 11x14, I wouldn't worry about any of those lenses, but would not use that Componar.

I'm sure there's sample variation in the 50mm Nikkor's, too. If you can't see anything in prints, it's probably not a loose element f/11 is perfectly reasonable for printing, too. I don't know why people hate on its quality, mine is better than an old Componon I tried.

Re: the 80mm Rodagon. It sounds like the one I got new back in the early '80s. The aperture ring should pull down slightly and disengage the click stops. I think the theory behind that was to allow continuous aperture setting for "zeroing" in on exposure when using enlarging meters. (now that's how I recall it...)

Over the years it's been my go to lens for 6x6.

Not sure if the modern lens specs correspond or not...

fretlessdavis said:

Yeah, your Rodagon sounds fine to me! Unless you're pushing past 11x14, I wouldn't worry about any of those lenses, but would not use that Componar.

I'm sure there's sample variation in the 50mm Nikkor's, too. If you can't see anything in prints, it's probably not a loose element f/11 is perfectly reasonable for printing, too. I don't know why people hate on its quality, mine is better than an old Componon I tried.

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Unfortunately, I don't print large I don't have large enough trays and the paper is a bit expensive. For now, I print mostly at 8x10 (20x25 cm).

So we agree. The Nikkors and the Rodagon are fine but the Componar isn't that good.

I can't say the 50/4 is bad, it was my first enlarging lens and gave me beautiful pictures. But from a comparison I can see a difference with the 50/2.8 to be sharper to me. I haven't printed with the 50/2.8 yet, it is quite new I am sure that a difference in prints won't be visible.

Dave Swinnard said:

Re: the 80mm Rodagon. It sounds like the one I got new back in the early '80s. The aperture ring should pull down slightly and disengage the click stops. I think the theory behind that was to allow continuous aperture setting for "zeroing" in on exposure when using enlarging meters. (now that's how I recall it...)

Over the years it's been my go to lens for 6x6.

Not sure if the modern lens specs correspond or not...

Click to expand...

Yes, that is the one I have. I confirm it is created at about 80's as I checked the serial number with a database I found.

On the modern specs I can find a 80mm f/4 Rodagon. I guess that if my f/5.6 and the f/4 have no big differences, then the specs could fit me.

geostog said:

Unfortunately, I don't print large I don't have large enough trays and the paper is a bit expensive. For now, I print mostly at 8x10 (20x25 cm).

So we agree. The Nikkors and the Rodagon are fine but the Componar isn't that good.

I can't say the 50/4 is bad, it was my first enlarging lens and gave me beautiful pictures. But from a comparison I can see a difference with the 50/2.8 to be sharper to me. I haven't printed with the 50/2.8 yet, it is quite new I am sure that a difference in prints won't be visible.

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Yup! It'll be difficult to tell any difference at 8x10, and only very nice negatives will benefit all that much, but since you have the 2.8, print with it anyway.

I got my 50 f/4 for free... I got it for $10 shipped online, and the seller sent it attached to half the head of a Durst F30. I tried to return the enlarger pieces knowing the enlarger would be useless without them, but the lady got confused and just gave me a full refund and didn't want the other stuff back...

Best lens for 35mm 8x10's I've had, though!

"But I have never made prints to check the performance of my lenses".

Well, you should. I mean, that's all that counts, right? How the lens makes prints should be the only standard to go by.

The 50 2.8 Nikkor N is a very fine lens, even used at f4. The N, "new", version has the illuminated aperture. All of the 6 element Nikkors I've tried from that era or later are amazingly good. Other people apparently knew this back then, but I was a little late to realize how good they are. 4 element lenses are okay, but need to be stopped down much farther for corner sharpness.

My results with 6 element German lenses have been much more mixed than I would have expected.

Enlarging lenses are subject to wear. They get banged around, and sometime something comes loose or slips out of alignment. That can affect the sharpness.

Not all enlarging lenses with a given name are the same. The EL-Nikkor 50mm f/2.8 is just plain a better lens than the 50mm f/4 version. I'm not sure about the Rodagon, but the design when it was made might be less shap over the field than Rodagons of a different era. The Componar is a low cost lens, not nearly as good as the Componons.

For tests of enlarging lenses, see Ctein,s book "Post_Exposure".

@fretlessdavis: I also got my 50/4 quite cheap, for just 30 euros including shipping. And the surprise is the 50/2.8: in absolutely mint condition, to me it seems new, for only 28 euros including shipping!

@momus: I will surely will make some careful test prints to check both the center and the corners of a given aperture at various apertures of all my lenses. That will eliminate any subjective factor.

@Mark: Yes, the Nikkor 50/2.8 I have has the illuminated aperture, so it is the N version. I wasn't sure because there is no N written on it.

@nworth: I wish I wouldn't have bought the Componar, I found it quite cheap an bought it. It was cheap, so no big loss.

@chip: I am reading that book and is really detailed. That man surely had some serious tests!

fretlessdavis said:

I was getting results like that with my enlarger lenses, but it was the film slightly sagging in the holder. Try using a glass carrier and compare. My EL-Nikkor 50mm f/4 is incredibly sharp on the entire frame @f/8. My Comparon 75mm (I know, not a componon... but it's optimized for the 8x10-11x14 range, and I couldn't tell a difference between it more expensive lenses at an 8x10) is also ideal at about f/8, except with Foma film, which needs f/16 because it's so curly and won't stay flat like FP4 and Acros do.

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I 'm currently enlarging small format to 8x12 with a Valoy 2 or 1c. No issues with alignment with the enlargers. I was shocked the El Nikkor 50/4 rendered images with less flair and increased contrast vs a 50/4.5 Focotar at f/5.6 & f/8. In fact, my perception was the 6 element (N) El Nikkor for this one enlargement factor and one negative was no better.

The Focotar has dust, a few wipe marks, no fog and is in average condition. The other optic in mint condition. I also see a difference between the Nikkor 50/4.0 and Focotar under a grain focus device.

I'm not saying a Nikkor 50/4 is better than a six element for all enlargement factors. My lens examples may be an anomaly. However, the late Barry Thornton writes in the book, Edge of Darkness, of a similar experience with his Anaret 50/4.5. I'm satisfied using the 50/4 for 8x10s to 8x12 on the Valoy. On the 1c I get vignetting at 8x if using a lens other than the Focotar.

I'll go back and test the Companon, f/2.8, Nikkor f/2.8 against the Nikkor f/4.0 at 8x. But I would not be surprised if there was no real difference. Enlarge at 5x and surely the 6 element optics would be better.

My experience is similar to Richard’s. I have a Schneider and a Fuji 6 element 50mms but my old 4 element Wallensak rapid, (not so rapid at F4.5) appears to me to have more contrast and is sharper in the corners than either of my 6 element lens, at least up to an 11X14. On the other hand my 90mm Wallensak is not as sharp as my Schneider 105.

Slight haze is very common in 6 element enlarging lenses. Generally easily cleaned.

Recently I got hold of a dirty and clunky Rodagon 180/5,6 from the late Sixties for about $15. Aperture was sticky, stops barely clicking and blades had some oil. Took a bit of time to clean it and adjust as good as I could, but in the end I had a almost-nice looking lens, with a few small scratches. Put it on my Fujimoto under a 4x5" Efke neg and above a sheet of Ilford WT FB @f8-11 and BANG! - a fabulously nice 12x16" print.