Using APO enlarger Lenses

[Ed Sukach]

Dear Ed,
-- that yes, I could see the difference caused by diffraction, but probably not in many 'real world' pics rather than test charts, and that circle of confusion must be related to degree of enlargement and viewing distance.

Are you sure that the error you saw was caused by diffraction?

The question remains unanswerd here: "1/60th mm for 35mm format; 1/30th mm for medium format - how was this determined?"

I think you are closer to the answer than you realize.

You seem to agree with the idea that my work is "total crap". Am I correct in this assumpion? - Not that I've asked for critique before in this discussion - just curious.

 

[Early Riser]

You seem to agree with the idea that my work is "total crap". Am I correct in this assumpion? - Not that I've asked for critique before in this discussion - just curious.

Ed, You put Roger in an uncomfortable position, unlike me, he is far too cultured and gentlemanly to answer such a question.

 

[Ed Sukach]

Ed, You put Roger in an uncomfortable position, unlike me, he is far too cultured and gentlemanly to answer such a question.

Other than the fact that I am completely confident in Mr. Hicks ability to speak for himself, I'll agree.

 

[Early Riser]

You seem to agree with the idea that my work is "total crap". Am I correct in this assumpion? - Not that I've asked for critique before in this discussion - just curious.

Ed why do you care? In previous postings, if I am paraphrasing it properly, you talked of not giving credence to any criticism or critique and not letting anyone "stifle your vision"? So why put Roger on the spot? And besides if Roger said he loved/hated your work it's obvious it wouldn't change what you do, so this is moot. Me, I'll tell you I don't like your work and not feel good or bad about doing so, for Roger it's a different story.

 

[Roger Hicks]

[A]Are you sure that the error you saw was caused by diffraction?

B You seem to agree with the idea that my work is "total crap". Am I correct in this assumpion?

Dear Ed,

A above: On re-reading (with quote), yes, I'm 99.99% sure that the image degradation I have seen/could see in those cases is caused by diffraction, as there is no other hypothesis that so neatly fits the facts. (I have added 'A' and 'B' to your quotes for ease of answering.)

B above: Not for one moment. I did say that de gustibus non disputandum est but I had no intention of commenting one way or the other on your work.

Cheers,

Roger

 

[Ole]

Uh .. "parallel" is really not the characterisic ... If both sides are, in fact, FLAT, there will only be a shift in image placement. If either surface is not flat, you are right... there will be a "focal length."...

If the sides are flat but not parallell, you have a prism. Same difference, only worse: You get misalignment of the optical axis, chromatic aberration, and differential focus shift.

 

[Early Riser]

Like I said, Roger is a gentleman.......and you can be proud that he doesn't think that your work is "total crap".

 

[david b]

Anyone looking for a Rodenstock APO-Rodagon 50mm lens?

 

[Early Riser]

Anyone looking for a Rodenstock APO-Rodagon 50mm lens?

Does it stop down to f 32?

 

[GFDarlington]

Hi. Remember me?

A few days a go I asked what I thought was a fairly reasonable question about how I should use my new enlarger lens. Since getting a couple of responses that seemed quite useful and informative, and which I think I was able to decypher correctly, I've seen a further 50 or so messages posted, in language that sometimes seems to border on the personally insulting (not to me I hasten to add), such that at times I've felt like the child in the Kramer V Kramer film who sits looking up at his elders and betters giving each other a hell of a verbal beating for the most innane of reasons. Only three of you have addressed your comments directly to me, which, in community that I thought was keen to share information and encourage those who are new to analogue photography to learn the ropes and master the skills needed to develop, is both a little surprising and dissapointing.

Do I really want to post to this site again asking for information? Maybe in future I'll just stick to looking at the piccies in the gallery area for my inspiration.

Perhaps its time to take a hard deep breath and count to ten!

Graham

 

[Roger Hicks]

Dear Graham,

I'd have thought that reading a debate between different viewpoints might help you towards an informed decision, instead of just being told "Do this: it will work." You must have seen from the above that there are differences of opinion; do you have a problem with this? I'd heartily second Ed's advice to make prints from full aperture to f/32, and see if you can see a difference -- and whether this difference matters to you. I'd also agree with Earlyriser: most people will see a difference in some pictures.

What sort of answer did you want?

Cheers,

Roger

 

[Dave Miller]

Graham,
Having counted to ten consider whether or not you received the information that you wanted.
Threads always wander on these forums; they seem to obey the same rules as Chinese whispers, so allowances have to be made.
I’m sure that if you revisit the thread next year it will have moved on even further – especially if Roger, and Ed have anything to do with it.
I guess the knowledge search can be a little like panning for gold; one has to sift through an awful lot of rubbish to find the nugget you were looking for.

 

[Ole]

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!). ...

Hi Graham!

As you've discovered, some subjects are indeed like "lighting the blue touch paper" here on APUG. And since we're not allowed to discuss film vs. digital, we tend to get passionate about very small differences - or failing that, whether very small differences are large enough to be seen, and if so with what kind of equipment under what circumstances.

and then we get sidetracked into discussing a similar question; in this case it was filters.

In most cases the moderators (myself, or one of the others) would intervene at some point and at least remove the more personal comments. This time we were surprised at the speed of "deterioration", and by the time I discovered what was going on I decided that it was easier to answer the current question than to start editing the whole thread.

We're not normally this bad. But then again many would say that if we were "normal" we wouldn't be here in the first place, but at some other forum discussing the latest updates to PS, new inksets for Epsons, or how many thousand exposures you have to make in one location to be sure to get a good one. And by the way the shutter on this camera is rated to 50 000 exposures, isn't that low?

Anyway: Questions do get answered here, but the answers are often not limited to answering the original question.

 

[GFDarlington]

Cheers guys (and, yep, no obvious sign, so far, of a feminine calming affect on this particular thread!).

I was very happy with the information that I initially received. As someone fairly new to this I thought the initial responses were pitched at about the right level for my understanding - as I said I got the gist of things, particulalry over the point of learning by looking and testing things out and forming my own judgements. Very useful advice. But its not so easy "reading a debate between different viewpoints (that) might help you towards an informed decision" when that debate is pitched way, way above your own technical understanding. Few of the more recent responses seemed to be written on the basis of enlightening an APUG newbie, rather there seemed to be a bit too much walrus on the beach like thrashing about going on for my liking.

Yes, I know there's sometimes a bit of rough and tumble on this site, and that a lot of tongues get planted firmly in a lot of cheeks. All I was asking was that some thought be given to the question that was initially asked and the particular advice that might be needed, rather using the topic as an excuse to fight particular personal crusades.

By the way Dave, are you really suggesting that some of the observations made previously might be rubbish? Yikes, could be time to put the hard hat back on again!

Graham

 

[jd callow]

Graham
I answered this a year or so ago, based upon my experience in the darkroom. I'm sorry I didn't repeat it here. I tend to think I'm less experienced then some here or at least I tend not to obsess about the minutia so I generally don't answer these posts.

Essentially the best aperture on any given lens is the one that gives you sufficient time to make the enlargement. This comment requires some assumptions. 1) wide open and shut down or even past f16 is generally not a good idea. Reasons are stated in this thread; and 2) that the lens is in good shape and the enlarger is aligned.

The premise is that most good lenses are good across a pretty wide range of apertures and so if you need time to dodge you may need to stop down a bit to buy you that time. I have found that glass carriers, an aligned enlarger and a good lens will work well from 1-stop in through a couple stops shy of its smallest aperture.

The story is that most lenses are at their best a couple stops in -- I haven't found an instance where I've noticed this to be true (or false). I have noticed that the projected image is softer wide open.

Sorry for the flippant remark earlier in this thread, I should have started editing posts instead.

 

[Early Riser]

This wasn't that bad, there's hardly any blood on the floor! What you need to look at Graham is besides the messiness of the thread is how many things, photographic things let me specify, that you learned. If you learned anything more than just the answer to your question, and if any of that new knowledge was brought to the surface by the stirring of the pot, then it was all worth it.

But be clear on something, when you seek information on any topic in any online bulletin board or forum, you're going to hear information that is both factual as well as completely erroneous, and you need to be on guard that you do not accept the erroneous as fact and invest in it. Over time you'll come to find out who on a forum is a good source of reliable information, I suggest you look at people's work because it really is an easy way to see the level of photographic competency of people, look at other comments made on other threads and look to see if there's a trend in the POV regarding the topic discussed. There are some seriously experienced and knowledgeable people on APUG and there are also those with opinions as well but lack anything to support what they say, this is not unique to APUG.

 

[Robert T. McCarthy]

According to Ctein's book, "Post Exposure" pg. 65 the 80mm APO-Rodagon's
sweet spot is between F:5.6 and F:8. I own the Schneider 90mm HM and what I like about it, is that I can go next to wide open and get a decent print when using color or cromo film.

Regards.

Bob McCarthy

 

[GFDarlington]

Brian

Thanks for the useful advice and the measured tone of its delivery. Yes, I certainly have a learnt a little beyond the scope of my initial enquiry, and not all of it to do with photography! To understand a lot more I suspect I'd have to give up work and turf my family out of our part time laundry/darkroom in order to concentrate on testing the optical science that's being discussed. I can't afford to do that - I'm a humble enthusiast only. I learn bit by painful and expensive, bit and the knowledge I glean from APUG has often been invaluble in that process.

I've looked at your website on numerous occasions and some of your images are in my favourites folder. Likewise with Roger's books and magazine articles. Sometimes what I learn is technical, sometimes aesthetic. This sense or personal discovery is one of the aspects of photography I most enjoy. I'm just not so keen on that sense of learning being hi-jacked by what seem like personal attacks made by proxy on my behalf.

Graham

 

[Ole]

... I suggest you look at people's work because it really is an easy way to see the level of photographic competency of people ...

That might lead to the assumption that my technical knowledge is as crappy as my pictures - or even worse: as bad as my scanning skills!

Getting slightly back towards the original subject; at least one of my pictures here was printed with a wide open Rodagon 150mm. Not even the APO version. I wanted to get the exposure time down to below five minutes, and had a very dense negative and was doing lith printing. I was very surprised myself at just how sharp it was!

 

[Early Riser]

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

Graham as I never officially answered your question, and I do also own the 80mm APO Rodagon, let me see if I can give you some additional assistance. Some of these may have already been mentioned but for some strange reason I lack the desire to re read the entire thread.

It's true that the 80 APO Rodagon is at it's optical best at one stop down, however there are some caveats regarding this, first your enlarger must be perfectly aligned, second you need to use a glass carrier. Without these two things you are likely to have areas of the print in which the negative was not actually focused. To be honest you really should be using a glass carrier and you really MUST align your enlarger otherwise you're making your life much more difficult.

Regardless, the 80mm APO is a great lens, going down 2 stops is not going to show a degradation as compared to one stops down. However if you go 3-4 stops down, the grain will lose some of it's startling crispness. This may not be noticeable unless you do head to head tests at the other apertures. But no one would say that the image was out of focus in the enlarger.

If the enlarger is putting out too much light there are several remedies. I know that a dimmer was mentioned, but not all enlargers allow dimming the bulb and some bulbs when dimmed do not come back to the same brightness every exposure, this is most likely a dimmer characteristic as dimmers are not made for such precision usually, although there may be a very precise industrial dimmer (rheostat or potentiometer) available.

The more common methods are to simply use a lower wattage bulb, to add a heat resistant neutral Density filter in the filter drawer, or use a high quality screw in ND filter on the lens itself. You have an exceptional lens and I assume you want to get the most out of it, so I would use one of the other methods over stopping down to f 11 or 16. But once again without an aligned enlarger or glass carrier you will not approach the quality that the lens is capable of.

 

[JohnArs]

Hi Graham
I had the chance 4-5 years ago to ask a question to one of the engineers at Rodenstock/Linos in germany, because my mother language is german.
My question was what is the sharpest f stop on the enlarger lenses, and I told him on old cameras there was always a marking with the sarpest f stop if this would not make sence for the enlarger lenses.
His answer was he would think about the marking idea and told me for the APOs is the best to close 1-2 f stops and for the non APOs so means just the Rodagons with 6 lenses 2-3 f stops for the best performans.
What he said is true and correct if the neg is totaly flat the enlarger perfect adjusted and the paper also totaly flat on the board!
If not then you will get even better results if you stop aditionally 1-2 stops more down, but then you are loosing a bit of snap a pop allower!
So if you are a sarpness freak like me just start to make shure the enlarger is in perfect alliment!
I personaly go on my 35mm staff newer to a smaller f stop then 11 and this very seldom I prefer f5,6 -8 on my APO 40mm from Schneider
On the MF negs I go very seldom smaller the f11 to and on the 4x5 inch I go very seldom to f 16 because on thad normal Rodagon is the best f 11!
This are my rules and also vica versa I'm almost never use the lens fully open.
I personally sure for normal enlarment sizes you will not see a difference down to f 11 and on 4x5 down to f16 with only your eyes!
Hope it helps!
Armin Seeholzer

 

[Early Riser]

That might lead to the assumption that my technical knowledge is as crappy as my pictures - or even worse: as bad as my scanning skills!

Getting slightly back towards the original subject; at least one of my pictures here was printed with a wide open Rodagon 150mm. Not even the APO version. I wanted to get the exposure time down to below five minutes, and had a very dense negative and was doing lith printing. I was very surprised myself at just how sharp it was!

Ole, your depth of knowledge is extensive and obvious, it's your continuing desire to use lenses that require carbon dating to determine their date of manufacture that has some of us worried about you.

 

[Ed Sukach]

Ole, I might be worried about you on that rig in the North Sea ( ... still there?), but not in photography. I think you do very well in this field.

We recently had visitors from Christianstad (sp?). I tried my *very* broken Norvege/ Dansk in a few phrases. Wonderful people!

I remember being temporarily "stranded" above deck on the Laerdal ferry at twilight... a nearly overpowering experience.

 

[Roger Hicks]

But its not so easy "reading a debate between different viewpoints (that) might help you towards an informed decision" when that debate is pitched way, way above your own technical understanding.

Dear Graham,

Fair enough, but it's always hard to tell whether someone is a novice, or a long-time practitioner with severe hardening of the categories. There's also the 'Bullshit Baffles Brains' argument: there are always those who will set themselves up as authorities and give out ex cathedra advice which, unless challenged, might be taken as authoritative despite being partially misleading or indeed on occasion flatly wrong. This is not an especial reference to this thread, but a general observation.

Cheers,

Roger

 

[David Brown]

There's also the 'Bullshit Baffles Brains' argument: there are always those who will set themselves up as authorities and give out ex cathedra advice which, unless challenged, might be taken as authoritative despite being partially misleading or indeed on occasion flatly wrong.

Cheers,

Roger