Using APO enlarger Lenses

GFDarlington · Jul 16, 2007

Hi all

I have recently started using an XPan and I soon realised that I needed something bigger than my El Nikkor 50mm enlarging lens to get decent prints from my LPL 7700 enlarger. I have recently purchased a second hand Rodagon APO 80mm F4 which I have just started using.

I have read that I need only stop this down one stop to get the best resolution from the lens but this is giving me ridiculously short enlargement times of around 10 seconds for reasonably well exposed negatives. This is leaving me no time at all for any sort of contrast control manipulation. Is there something I should be doing, other than going up to F11 or F16, to give me sufficient time for any dodging or burning? Or, am I going to have to use this lens only for really big enlargements on 20x16 or bigger paper, which, in fact I can't easily accommodate in my small darkroom anyway?

Helpful comments much appreciated.

Graham

payral · Jul 16, 2007

Just dim your light with a dimmer, change your lamp for a smaller wattage or use a ND filter.

Ian Grant · Jul 16, 2007

Graham it's quite normal to have to stop down your enlarger lens and f11 or f16 are fine.

Well balance negatives are not as dense as over exposed / over developed negatives so need shorter exposures, or stopping down. The extra speed of the enlarger lens is particularly useful for larger print sizes, and also makes focussing easier.

Ian

Lopaka · Jul 16, 2007

Ian is correct. The APO will give better results at f5.6 than a non-APO, but they work just fine stopped down.

Bob

Ed Sukach · Jul 16, 2007

Oh, boy - the old "diffraction" terror again!

I would suggest you *try* that lens through the entire aperture range making prints from *one* negative (paying due attention to reciprocity), shuffle the results and try to see one iota of difference between any of them.

I've done that with lesser lenses than the Apo Rodagon - and have reached the inescapable conclusion that the aperture selection doesn't make a diddley-damn bit of difference in quality - in any enlarging lens above the level of a Holga.

I am confident enough here to wager a treasured bottle of Oban 'Little Bay of Caves' West Highland Single Malt Scotch Whisky. 14 Year Old.
I couldn't be more confident than that.

Roger Hicks · Jul 16, 2007

Ed Sukach said:
Oh, boy - the old "diffraction" terror again!

I would suggest you *try* that lens through the entire aperture range making prints from *one* negative (paying due attention to reciprocity), shuffle the results and try to see one iota of difference between any of them.

I've done that with lesser lenses than the Apo Rodagon - and have reached the inescapable conclusion that the aperture selection doesn't make a diddley-damn bit of difference in quality - in any enlarging lens above the level of a Holga.

I am confident enough here to wager a treasured bottle of Oban 'Little Bay of Caves' West Highland Single Malt Scotch Whisky. 14 Year Old.
I couldn't be more confident than that.

Dear Ed,

I'm reasonably confident that I could find at least one lens where I'd probably win -- some really do have a 'sweet spot' across a stop or two, while quite a few are not at their best at full or minimum aperture -- but in order to prove my point I'd need to make lots of 12x16 inch prints of test charts, which would just be another way of demonstrating pretty much what you have just said.

Besides, I prefer the island malts...

Cheers,

Roger

fschifano · Jul 16, 2007

And there you go. While it's true that you can loose some resolution to diffraction, it is equally true that you will not see the differences. The fine details that are lost are too small to be seen in a print of modest enlargement ratio. When you do make a large print, or crop very aggressively, the differences might begin to show. But of course when you do that, the enlarger head height is quite high and you'll be happy to open the lens up to shorten the exposure time. You see, it all works out pretty handily. Stop worrying, and stop the lens down if you need more time.

srs5694 · Jul 16, 2007

Ed Sukach said:
I would suggest you *try* that lens through the entire aperture range making prints from *one* negative (paying due attention to reciprocity), shuffle the results and try to see one iota of difference between any of them.

I agree that this is good advice. A hands-on test with your own equipment is far better than somebody else's opinion. Testing your lens's performance at a variety of apertures will only take a few minutes.

I've done that with lesser lenses than the Apo Rodagon - and have reached the inescapable conclusion that the aperture selection doesn't make a diddley-damn bit of difference in quality - in any enlarging lens above the level of a Holga.

Here I must disagree. I've done the tests with several lenses (the best being a 50mm Nikon EL-Nikkor f/2.8 -- well above the level of a Holga's lens) and I have found noticeable differences in all of them. The differences tend to be fairly small, though, and with the better lenses they're only likely to be noticeable at extremely large or small apertures. For instance, that Nikon has an aperture range of f/2.8 to f/16, and differences from about f/4 to f/11 are almost undetectable. IIRC, all of the lenses I tested had "sweet spots" at f/5.6 or f/8, although with the better ones, such as the Nikon, you'd need an 11x14 enlargement and a loupe to be able to spot the differences between that setting and nearby ones. Since I've never used an APO Rodagon 80mm, I can't comment on it specifically.

Ed Sukach · Jul 16, 2007

Yeh, yeh!! .. I've heard all of this before.

I take exception to the philosophy that "Everything **MUST** be done to satisfy the highest possible parameters - absolutely - without exception.

I'll stand by my statement; The greatest majority of enlarging lenses, by far, will not produce NOTICEABLE differences in quality through their entire aperture range. Could I find (some) differences using (more or less) sophisticated testing equipment? Probably - most likely -, but nothing that would be noticeable in the real world.

My printing is done with one goal in mind - Gallery Exhibition (major goal - that can be expanded to include portfolio, hanging on the wall in someone's home, advertising copy ...). I have yet to see anyone - in any gallery - running around using a loupe to determine if the print was made to the ultimate best performance of an enlarging lens.

As a matter of fact, my most used enlarger accessories are two "soft-focus" filters - I bought them at a "junk bucket" sale, really out of curiosity - because they fit my Rodenstock enlarging lenses (40.5mm filter size). They work wonders in portraiture, removing slight skin imperfections, etc.

Roger Hicks · Jul 16, 2007

Ed Sukach said:
Yeh, yeh!! .. I've heard all of this before.

I take exception to the philosophy that "Everything **MUST** be done to satisfy the highest possible parameters - absolutely - without exception.

I'll stand by my statement; The greatest majority of enlarging lenses, by far, will not produce NOTICEABLE differences in quality through their entire aperture range. Could I find (some) differences using (more or less) sophisticated testing equipment? Probably - most likely -, but nothing that would be noticeable in the real world.

My printing is done with one goal in mind - Gallery Exhibition (major goal - that can be expanded to include portfolio, hanging on the wall in someone's home, advertising copy ...). I have yet to see anyone - in any gallery - running around using a loupe to determine if the print was made to the ultimate best performance of an enlarging lens.

As a matter of fact, my most used enlarger accessories are two "soft-focus" filters - I bought them at a "junk bucket" sale, really out of curiosity - because they fit my Rodenstock enlarging lenses (40.5mm filter size). They work wonders in portraiture, removing slight skin imperfections, etc.

Be fair, Ed, you're shifting ground slightly here. Of the last three posts, we've all agreed with you that the differences are trivial and unimportant, but usually detectable at some apertures (even if only maximum and minimum) with serious methodical testing via big enlargements, usually of test charts -- NOT real pictures. Which is, if you look at it, complete agreement in practical terms, even if we believe we could win a bottle off you.

Cheers,

Roger

Dave Miller · Jul 16, 2007

Hey you two, stop squabbling, you are in complete agreement, in case you haven’t noticed.

Ed Sukach · Jul 16, 2007

Roger Hicks said:
Be fair, Ed, you're shifting ground slightly here.

I've realized and accepted that level of agreement. As usually happens, in an attempt to be concise, I leave out a number of those who will grind "micro-fine" (present company most assuredly excepted) on each and every letter and punctuation point I may write. I'm trying to respond IN GENERAL, by expanding and I can easily see how that can be interpreted as "slightly shifting".

I've thought of a simile here: I have discovered, analyzed, and calculated that my Honda Accord has an Optimal Point of Performance at precisely 38.07 MPH (61.27 KPH); where mileage, load carrying ability, wear and tear on the machine, driver's fatigue, and sundry other characteristics are at their most favorable.
The idea is to operate that vehicle as efficiently as possible - therefore I will install a speed control device which will LOCK the vehicle speed at 38.07 MPH (61.27 KPH) in ALL driving circumstances.

Sheer stupidity? Of course! Driving at that speed through heavy traffic, or conversely, on a heavily traveled superhighway will most certainly result in a tangled mass of metal.

The point I'm trying to make here is that, AT TIMES (I'll even be more specific - MOST of the time) flexibility is more important than "ultimate efficiency." Therefore, if you wish to stop down an enlarger lens to allow more time for dodging, burning, or whatever, it is a far, far better idea to do so than to blindly remain a slave to the idea of "only one single, optimal aperture".

Come to think of it ... why else would the manufacturers install iris diaphragms in enlarging lenses?

GFDarlington · Jul 16, 2007

Yikes! Talk about lighting the blue touch paper and standing well back? I am now beginning to realise that no questions are straightforward ones on APUG. Not only that, but prized bottles of whisky seem to be at stake (although IMHO to be truly prized they would have to be whiskey!).

Thanks for all of the very passionate responses. To someone only two years new to B&W analogue photography some of the observations are way, way over my head, but I get the gist of what's being said: Don't be too worried about stopping down to get a decent length of timed exposure and only consider using f5.6 if I am going for decent sized exhibition prints. Oh and dont be afraid to test and trust to my own observations. Emm, seems quite simple, really....

Ed Sukach · Jul 16, 2007

GFDarlington said:
Not only that, but prized bottles of whisky seem to be at stake (although IMHO to be truly prized they would have to be whiskey!).

I've checked. On the Oban bottle, it is indeed spelled without an "e" - "whisky".

Oban is not perfect, but as far as I'm concerned - CLOSE ENOUGH!!! LOTS of Scotch/ Scot's Whisky/ Whiskeys are CLOSE ENOUGH!

We are all entitled to our own tastes ... and we have to have a great deal of tolerance for the tastes of others. I've heard that *some* might even prefer Islay. I know that is hard to understand, but - there is NO accounting for taste - no matter how bizarre!

I shall now retreat into my underground bunker and watch through my closed circuit TV system for the fireworks that are sure to occur "out there".

Roger Hicks · Jul 17, 2007

Ed Sukach said:
Come to think of it ... why else would the manufacturers install iris diaphragms in enlarging lenses?

Dear Ed,

Sheer malevolence, of course; they don't want us to get the best performance out of them. The same reason they always lie about ISO speeds and give the wrong development times...

Incidentally, my own understading has always been that whisky is Scotch and Whiskey is Irish. And as well as Islay, don't forget Jura and Orkney.

Cheers,

Roger

Early Riser · Jul 17, 2007

All lenses have optimal f stops, all one has to do is check any lens test chart. The point is at what aperture do you have the best combination of resolution and DOF on the negative. All lenses also have optimum reproduction ratios, same is true for enlarging lenses. In most cases these differences will go unnoticed on a B&W print because a B&W print is in itself a somewhat lower resolution material. The only time the optimization of the lens, that is using the "best" aperture at the "right" magnification will be on large prints, and even in that case there are enlarging lenses optimised for extreme enlargement.

There are other elements to getting the best out of a lens such as insuring perfect alignment and using glass carriers. If you have not done both, it really doesn't matter much what aperture you use except of course to use DOF to compensate, poorly, for those deficiencies.

Daniel_OB · Jul 17, 2007

Apo-Rodagon lenses are the best photo-enlarging lenses available money can buy. They will extract just last drop of information from your negative. They will not improve noticable by closing the oppening, and will stay nearly the same from max oppening up to difraction penalty (say F8 or F11). However this is not true for "other" enlarging lenses.
I think your apo-rodagon is overkilled for x-pan lenses, and rodagon or componon-s should be more than enough.

www.Leica-R.com

Ed Sukach · Jul 17, 2007

Daniel_OB said:
... They will not improve noticable by closing the oppening, and will stay nearly the same from max oppening up to difraction penalty (say F8 or F11).

I am reasonably familiar with lens data sheets. On none of them have I ever found an entry for "diffraction penalty".

There is a *reason* why the choice of f/stops is limited on BOTH extremes - and that reason is the manufacturer's quality performance requirements. In short, they will not allow an aperture to be used that has a detrimental effect - beyond their standards.

I can assure you that the major players - Rodenstock, Schnieder, Nikon, Elgeet, Wollensak ... many others ... all have *very* high standards - to do otherwise would result in a LOT of unhappy photographers - and drag their image and 'competitiveness' into the toilet.

P.S. No kidding!! You "slash" the waters with a fly line as well ...!!! Now, if I could only find a way to avoid "wind knots"....

David Brown · Jul 17, 2007

GFDarlington said:
Yikes! ... I am now beginning to realise that no questions are straightforward ones on APUG. ...

Yep! Welcome to the club.

Daniel_OB · Jul 17, 2007

Ed

There is a *reason* why the choice of f/stops is limited on BOTH extremes - and that reason is the manufacturer's quality performance requirements. In short, they will not allow an aperture to be used that has a detrimental effect - beyond their standards.

macro lenses, say Nikkor 2.8/55, are of extreme accutance (sharpness). However the same Nikkor go up to F32, and result you know. Difraction take its toll even with Leica Apo-Macro-Elmarit 2.8/100, and it is not up to manufacturer.

fschifano · Jul 17, 2007

Daniel_OB said:
macro lenses, say Nikkor 2.8/55, are of extreme accutance (sharpness). However the same Nikkor go up to F32, and result you know. Difraction take its toll even with Leica Apo-Macro-Elmarit 2.8/100, and it is not up to manufacturer.

Yes, and there's a reason for that too. I'm not arguing that stopping a 55mm macro Nikkor will not cause some loss of image quality from diffraction, but think about the application. DOF is a precious commodity in macro photography, and sometime you need to eek out as much as possible. Often, the loss of resolution from diffraction will be completely swamped by an insufficient DOF for the image. It's up to the photographer to decide which is more important.

Ed Sukach · Jul 17, 2007

Daniel_OB said:
...macro lenses, say Nikkor 2.8/55, are of extreme accutance (sharpness). However the same Nikkor go up to F32, and result you know. Difraction take its toll even with Leica Apo-Macro-Elmarit 2.8/100, and it is not up to manufacturer.

No, I don't "know". Macro lenses are designed to be "biased" toward a projected use: occasional close-up work, and their design reflects that use. I have *no* idea whether or not "acutance", resolution, contrast, or anything else is better - or worse - than with non-macro lenses.

Diffraction is determined by the EFFECTIVE focal length (and for extreme close up work, that will be considerably longer than that marked on the lens - which is focal length when focused at infinity), an acceptable "circle of confusion" and aperture diameter. I have the formulae in question - but I have either the time nor energy to calculate "limits" at the moment.

I have made exhibition prints at enlarging lens stops of f/22, f/32 ... and - I don't know ... even smaller. I can still see "grain" - unless I either de-focus or use "softeners".

cao · Jul 17, 2007

I don't think it's just a matter of grain or not, but how crisp that grain is. I can see the grain turn to mush on my focuser as I go to apertures higher than f/5.6 on my APO Rodagon 50/2.8. I like to print for crisp grain, and I tend to use ND gels in the filter bay rather than stop higher than f/5.6. This is not invariable as I recently printed a piece with very slight intentional defocusing, but it certainly is my general practice to avoid stopping down any more than two stops from open. I also tend to laser check my enlargers and print with a glass carrier. Based on my direct experience, I think Roger would likely win your bet for say an 11x14 from 35mm (i.e. 9X), though perhaps he'd detect the difference in a smaller enlargment.

Early Riser · Jul 18, 2007

Ed Sukach said:
I have made exhibition prints at enlarging lens stops of f/22, f/32 ... and - I don't know ... even smaller. I can still see "grain" - unless I either de-focus or use "softeners".

I would advise strongly against using enlarging lenses at f22-32, there is visible diffraction and the lenses are definitely not at their best. You can have serious diffraction and still see grain, however just seeing grain is a poor determining factor of sharpness. Seeing grain means that the image has been focused and is not indicative of a sharp image. Unless one is doing under the enlargement perspective controls, requiring an inordinate amount of DOF, there is no reason the use an enlarging lens at 22-32. Especially on an "exhibition" print.

The old adage about an enlarging lens being it's best 2 stops down is usually a safe bet. In the case the APO Rodagons, and I'm speaking both from experience with my 80mm,105, 150 and 180 APO Rodagons, as well as their MTF charts and repeated statements from Bob Soloman, indicate that they are best one stop down. However with optics as fine as these, one would be hard pressed to discern much difference between one and two stops down, and only under the most critical evaluation would the differences be obvious.

Ed Sukach · Jul 18, 2007

I've never said that enlarging lenses were NOT "best" at any given aperture/s. There *IS* an "optimum* point - but I submit that this is folly - pure anal overkill - to be slavishly tied to "the one and only" aperture. Enlarging lenses are *very* useful throughout their entire aperture ranges.

The same philosophy applies to camera lenses (a lens is a lens, is a lens ..) - there *IS* a "best" aperture - but I think you would find few photographers who would consider locking their iris diaphragms to *one* aperture.

That you for your suggestions and advice. I will give them due consideration.

... Let me think about destroying "sharpness" and leaving "grain structure" intact. Sounds like an interesting lens.

Using APO enlarger Lenses

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