Enlarging lens optimisation -- Any thoughts?

[Shen45]

I don't enlarge much beyond 16x12 from my 5x4 negs and was curious to know on this blistering hot New Years day if anyone has ever noticed a difference using enlarging lenses optimised for 10X's [which I think the Componon is] compared to say a Comparon [which are I think optimised for 2 - 6X's enlargements] or equivalent Rodenstock or other brand.

Is anyone aware how the optimisation is achieved? Spacing? Number of elements?

If I'm correct I'm really only enlarging my 5x4 neg up to about 3X's.

If Bob Salmon is about he may have a good explanation.

Steve

[Mick Fagan]

Steve, I feel the heat almost as much as you, we had 42C yesterday and today was 41.9 as well, darkroom is red hot, don't need a safelight.

Many years ago when I was in a commercial photo lab environment, I was invited to a talk whilst in Germany for a printing industry show, (4 colour paper printing on Heidelberg press).

One of the discussions/talks was by Schneider Kreuznach regarding the optimum repro possibilities in conventional four colour printing. The basis is that it all starts with a very good, and optimised, B&W or colour print, which is then the camera ready print, used for the process.

This was in the seventies, about 78 or 79, would have to find an old passport.

The start of the lecture was interesting as they explained about conventional lens construction and the differences between the taking camera, enlarger and repro camera. With regard to taking camera, they were talking about view cameras.

At the time the conventional wisdom was, for good repro work, one required a copy print for quality half tone screening and/or colour seps, at approximately twice the size the final product was to appear in a magazine or book. The original repro print size was considered optimal, if it was at least twice the size but no more than four times the size, of the final screened image.

To accomodate this requirement, certain manufacturers, (Schneider in this case) had put together an optimum set of enlarging lenses for film to paper enlargement, which had their critical focus point at certain magnification sizes of their focal length. It was really important for sharp four colour printing that the original was as sharp as possible along with the desired contrast and detail being able to be transposed to the next step.

As we in a darkroom could be simple people, they were advertised as being designed for magnification of 4 to 6 times the format they were enlarging, or 10 times, or even 20 times, for the miniature format.

This was started in the fifties and was more or less finished by the time of the seventies. As repro camera work materials and the technicians got better in the sixties through to the seventies, this importance sort of got lost.

It was revived with the usage in darkrooms of colour and the better optimised lenses were heavily advertised with their times magnification factor in magazines for the general public, instead of just the printing industry and industrial photo labs.

Mick.

[Mick Fagan]

Now, to actually answer your question.

Yes, there is a difference with an optimised enlarger lens being used at it's optimal magnification factor.

More than a few times, we had to enlarge a slightly cropped picture directly to a 30x24" piece of paper from a 135 neg. You need absolute alignment of the enlarger, and, at that magnification, a glass carrier.

The only glass capable of doing this without going to a larger format interneg, were the Schneider or Rodenstock, 20x optimised enlarging lenses.

Well, other enlarging lenses were quite capable, but the best prints, in regards to definition, detail and apparent sharpness to the eye, as well as colour fidelity (fringing) were those lenses.

I personally run a set of 50, 100 and 150 Schneider Componon S lenses on my enlarger. I also limit myself to 12x16" paper, both B&W and colour, in my home darkroom. They are more than adequate for these purposes, even if I crop heavily in any of the formats, which I often do.

The best ever enlarging lens I have ever had the pleasure of using, is the Rodenstock 90mm Apo. Nothing by any other manufacturer, or Rodenstock, comes close to the performance of that enlarging lens.

Mick.

[Shen45]

Thanks Mick, excellent answer. I have just come in from the darkroom, 12 midnight and the temp here is now cool enough to do some printing.

I don't know if you are aware that some of the Melbourne APUGGERS are having a get together early January - around the 12th I think.

I would like to get there but two thousand k's for a Sunday morning get together is probably not on.

My wife and I met up with some of the Melbourne group at the Grampians and that was very worthwhile.

[Dan Fromm]

Steve, you asked what optimization involves. A lens' aberrations can be minimized for only one pair of conjugates (front to subject and rear to film distances). Enlarging lenses are supposed to be optimized for relatively near subject and far film, taking lenses for relatively far subject, near film. I say supposed to because at least one lens maker has sold exactly the same lenses for taking and enlarging.

These days (since the late '50s, early '60s for most but not all lens manufacturers), the conjugates for which a lens is to be optimized are inputs to the lens design program. Before then the designer used them in laborious hand calculations.

If you're thinking of, um, reoptimizing by tinkering with inter-cell spacing, don't.

[Shen45]

Thanks Dan,

No I'm a tinkerer but no I was just curious as to why one 150mm lens was optimised for say 4x's and another for 10x's and if there would be any visual difference if a 10x8 image that was made with each lens of the exact same 5x4 neg by the same printer using the same enlarger.

What if any differences would or could be apparent?

[Dan Fromm]

Steve, I'm not a mind reader, but I've been struck by the facts that Schneider recommended Comparons (enlarging Xenars) for lower enlargements than Componons (regular and -S, enlarging Symmar and Symmar-S respectively) and that Comparons sold for less. Makes me think that the two lines were pitched at different markets with different budgets. Small prints, less money (amateurs?). Large prints, more money (who?). Alternatively, perhaps Schneider wanted to sell a broad range of lenses that met all needs well rather than a narrower range of lenses than met some needs not so well. But speculation without solid information is fruitless.

If you google around you'll find a number of reports on battles of enlarging lenses.

[Bob Salomon]

Let's talk Rodenstock enlarging lenses. For this example we will use 35mm film as that and 6x6cm are the only film sizes that Rodenstock offered all of their various enlarging lenses in.

For very basic users who do not want or need to make prints larger then 8x from 35 mm Rodenstock makes the Rogonar which is corrected for up to 8x. No matter what you do you can not make a high quality 11x14" from this lens.

For more advanced users the Rogonar S is available.It is corrected for up to 10x is a 2.8 and makes excellent prints up to 11x14 but not a good 16x20.

For pros and advanced home printers there are three lenses to choose from: the 50mm 2.8 Rodagon which is corrected for up to 15x magnification and you can make an excellent 20x24" print with this lens.

For those that need even higher quality in this print range but do not have a long enough enlarger column to make the size prints required Rodenstock make the Rodagon WA (wide angle) series which will make a print 30% larger in size at the same column height as the normal lens (50mm) for the format. For 35mm that would be the 40mm Rodagon WA and it will make a print with better sharpness then the Rodagon at all print sizes up to 20 x 24 and will make excellent 24x30" prints. It is corrected for 20x magnification.

For the ultimate in enlarging quality the Apo Rodagon-N series will simply outperform every other lens commonly used for enlarging. It is also corrected for 20x and can easily make cropped 24x30" prints and outstanding smaller prints. While the 50mm is the commonly used version the discontinued and rather scarce 45mm 2.8 Apo Rodagon-N was corrected for 30x and easily made outstanding prints to 40x60".

The Apo Rodagon-N series replaced the older Apo Rodagon series and is a totally new design with different coatings, coverage and design. The former 90mm Rodagon would only cover 6x7cm when stopped down. The current 80mm Apo Rodagon-N covers 6x7 wide open and is superior in all respects to the older 90mm. A newer 90mm Apo Rodagon-N was introduced with the 45 and 75mm Apo Rodagon-N designs but all had a very short life.

For professional labs needing to make very large or mural size prints Rodenstock made the now discontinued Rodagon-G series. For 35mm these lenses were corrected to 50x magnification. Some uses for these lenses were making the designs on 4x8' wall paneling, making the large stand alone prints commonly used for advertising at airports, train and bus stations and for making billboards(not from 35mm these lenses were made up to 480mm for 30x+ magnification from 11x14 film). This lens series was incapable of making an acceptable 8x10. They were optimized for very large prints only.

Today digital has taken over the market that the G was formulated for so the entire G series has been out of production for a while. The 50mm G was the last one discontinued after the 45mm Apo Rodagon-N became available.

While the darkroom market has retracted lenses have been discontinued. Today Rodenstock no longer makes Apo Rodagon-N, Roganar S and Rodagon WA lenses for large format.

We used to bring to shows a book that Rodenstock printed of original prints at various magnifications made from a Leica negative shot on a Linhof Heavy Duty Pro tripod and then printed with each series of enlarging lenses and printed on a Durst 1200 with glass carrier in optimal alignment. These were printed at wide open and stopped down to optimal aperture for each lens. Prints were made at 2x, 4x, 8x, 16x and 50x from each lens and the prints were cut down to the same size and mounted in the book.

While at a fast glance the 8x prints from all were apparently acceptable when looked at carefully it became very apparent that there were significant differences in contrast and sharpness. Especially when looking at fine details like newsprint on a newspaper in the corner of the scene. It quickly became obvious that the best performer all around was the Apo Rodagon-N followed very closely by the Rodagon WA.

For extremely large prints only the G excelled and was followed by the Apo Rodagon-N.

For small prints, up to about 4x all were acceptable. But if you were going to make a 4x that is cropped only the Rodagon and up (except for the G) would make acceptable prints.

There was a strong need during the years where darkroom was still strong for complete darkroom kits that a dealer could sell as a package. That put demand on the lens manufacturers by the enlarger manufacturers for a low cost package lens that the enlarger manufacturer could package along with a lensboard and negative carrie to the dealer as a complete starter kit. Simple lenses like the Rogonar and similar lenses from Schneider, Durst, Meopta, Besler, Omega, etc. were made to fill this need. No serious printing is possible with these type of "student" lenses. Student lenses are basic lenses that are inexpensively replaced if they were damaged or stolen that were used in school, community and rental darkrooms.

[Mick Fagan]

Bob, very interesting, it brings back memories of mural enlarging using horizontal DeVere 10x10 enlargers.

We had one mural based horizontal enlarger set up which was actually designed around the enlarging possibilities of the G series of enlarging lenses.

Using the 10x10 enlarger we had the maximum enlargement possible with unbelievable sharpness using the 360 G enlarging lens. As I understand it all G series at the time (eighties) were optimised for 20 x enlargements. Therefore the mural enlargements were designed with a single piece of paper measuring 6' high by 18' wide maximum.

I remember we looked into the possibilities of 11x14 enlarging as there were quite a few instances where this would have been a viable proposition, but the cost factor for an extra 5' of length and still constrained by the 6' paper roll width from Kodak were not worth it.

The 480 G lens, was going to cost more than our new delivery van plus a drivers wages for 6 months. Without thinking of the additional cost of the steel wall for the enlarging paper, nor the lengthening of the darkroom to allow for the longer focal length.

I didn't know that they made a 30x 480 G lens, this must have been in the nineties when I was out of the game.

Mick.

[Bernard Kaye]

I am vindicated. When selling "photo": cameras, film, lenses, etc., pros in 35, 120, 4 x 5 and larger would come into shop complaining about enlarger performance. Not having this group's experience, I read what I could find and concluded two things: (1) many enlargers are not aligned and (2) Rodenstock was the way to go. They borrowed a Rodenstock promising to verify alignment and steady enlarger, used the lens, returned and bought it. For 35 and 120, Leica lenses were superb but were dependent on lighting systems in Leica enlargers to deliver optimum performance, as are Leica projection lenses in Leica projectors or the Leica produced Kodak Carousel: projecting a 35 in a Kodak Carousel is great but then project it in the Leica version of Carousel; tremendous difference.
Your enlarger's light source and how light is handled, no condenser, one condenser, two condensers, all this matters.
You have a burden in putting it all together, perhaps around the proper Rodenstock.
Bernie