I agree with you Michael.
One person mentioned powder, I used powder in my past career on a lisle camera, amazing stuff, but most of the work I was doing there was reduction of image size or SA only, not enlarging. I would think that powder would be troublesome with a big magnification.
Interesting thread, I was hoping that it would not be conclusively proven that better glass would give better prints, I would have a lot of explaining and reprinting.
Another way I neglected to mention for the Newton ring stuff is of course wet-mounting the negative, but I just didn't want to go there. I have no interest in doing anything like that.
I'm a notoriously paranoid perfectionist always thinking about ways to make things better, and tend to occasionally get sidetracked from actual photography into these experimental/technical rat holes. I think this particular one is over for me. Although I'll continue to be interested in any glass coating someone finds that prevents Newton rings, for now I'm done with this particular bit of insanity.
I don't think you have any explaining to do. Tice, Ansel etc - no coated carrier glass.
If your film will remain motionless during the exposure, I have found the T-max film base (and other maybe) to be stiff enough that it holds flat enough to be all in focus even wide open (f4) at 2x enlargement in a glassless carrier. You can check the focus spread from center to edge yourself if you have a scale on your enlarger column (should be less than 3mm*). I don't use glass with 4x5 when doing short exposures at 2x, but that is not a recommendation, just a statement .
Originally Posted by Michael R 1974
*CoC about about 0.15mm on the print
Last edited by ic-racer; 11-08-2012 at 09:01 AM. Click to view previous post history.
Strange reference, Michael - have you ever seen some of AA's negs enlarged to any significant
degree? They're pretty fuzzy by today's standards. That's why he always taught using non-glossy
paper for big enlargements! You can blame all kinds of things such as grainier films back then, lenses
unequal to today, poorer alignment in filmholders etc - but saying you don't need some kind of special glass because AA didn't use it is pretty self-defeating. Tice was largely a contact printer.
Yes, the ultimate cure would be wet mounting in something like scanner fluid. Carlwen once made
fluid carriers. But I have never been willing to risk that kind of mess.
Ok fair enough there are sharper prints than Adams. But I've even seen some contact prints of his that were not super sharp so I assumed any unsharpness in his work had a lot more to do with old camera lenses, camera alignment, film holders etc. Tice does do a lot of contacts but I have some enlargements that are razor sharp, also some Sexton prints made without coated carrier glass (some from medium format negatives) - they are as sharp as I can imagine. In any case my point was only that of the various print makers generally held in high esteem as meticulous craftsmen, relatively few of the big names have bothered to install high tech lens glass in their carriers. By the way for reference, the coated glass John Wimberley uses is from Durst. I don't know who actually makes it.
Actually I'd be curious to know if Christopher Burkett uses special coated glass in his carriers. His prints are certainly sharp, even big ones from medium format negatives.
I don't mean to say it doesn't matter and that they use plain window glass between the negative and the lens. What I'm saying is that most good quality stock glass carriers from Durst, Saunders, DeVere etc are/were made with optical glass flats, and that the difference in print quality between using an "ordinary" grade of optical glass and better optical glass (and/or coatings/multicoatings) is likely immaterial - unless the enlargement factor is very large, which I didn't test. I tested up to around 10x (from 35mm negatives) with Schneider/B+W MRC glass (and other glasses) vs the stock glass and other than the difference in transmission I did not see any difference in print sharpness.
I stuck with the Schneider glass in my modified 35mm carrier because I already had it from the tests, and the MRC coating is super easy to keep clean. In my Saunders 4x5 carrier I stuck with Schneider coated filter glass (MRC coating not available on glass big enough for 4x5 even from Kreuznach) but did not see any difference between it and the stock glass - although again with 4x5 I did not try huge enlargements - only tested up to 6x. I didn't modify my Inglis 4x5 registration carrier for testing is it would have been redundant. The glass Inglis uses is at least as good as what comes in the Saunders.
Regarding fluid mounting, I think this is still popular with people who do certain types of scanning. I feel the same way as you regarding the risk. It seems like a disaster waiting to happen, even with the best technique. And I don't like the idea of having to wipe my negatives with Pec Pads and cleaning fluid. The whole thing is too messy and complicated for me.
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I have no personal experience about wet scanning or printing but it seems that fluid scanning makes a dramatic difference in respect to dry scanning.
Originally Posted by Michael R 1974
Maybe (maybe) there is a marked gain in sharpness also when printing.
http://scanscience.com/ gives an example although this is a site from a liquid producer so it might be biased.
Considering your drive for quality and perfection I suggest you try it at least with some low-value negative. The gain you should get in quality is probably bigger than any improvement in the enlarger glass. Who knows, you might find an unexpected improvement.
Pec-12 is a very reliable liquid much praised by professionals in some fora and gives no problem at all. I personally use it occasionally to clean finger marks on the emulsion side. I never used it to remove scanning fluid but some people does this job regularly without any problem.
I would certainly try wet scanning if I had a scanner supporting it (with my desktop scanner wet scanning is not feasible).
My understanding is it is actually necessary in some drum scanning applications. I have no personal experience with scanning as it is not part of my workflow. I'm 100% analog and based on everything I've read, when making analog enlargements wet mounting serves only two purposes - (1) eliminating Newton rings, (2) reducing the appearance of scratches in damaged negatives if the liquid has the same refractive index as the film base. I've never heard of it improving sharpness or grain masking, but I'm no expert in fluid mounting so I could be wrong.
As for perfectionism, it has to end somewhere . Fluid mounting is just not something I want to get into. Even if I did, I would expect it to be problematic or entirely incompatible with masking, which I sometimes use.
Michael - you can go to Chris Burkett's website to see illustration of his equip protocol. For those of
us who did high-end Ciba work (or any advanced color enlarging for that matter), precision glass
carriers are an absolute must. Chris interchanges precision registration carriers into a common base
on the Durst, each carrier suited to a different mask. It's a lot like working with separation negs in
dye transfer printing. His enlarger with this kind of system was probably close to seven figures to
purchase. I have a little different system, mostly custom made, and a little different protocol for
skinning the cat, but have since moved on to experimenting with color negs, since Ciba is in demise.
For my own work I solicited samples of AN glass from all over the world (not many choices now).
This kind of work is a lot more involved than simple black-and-white printing, and one simply cannot
cut the corners. Some of these kinds of neg carriers would run four to six thousand dollars apiece.
And you can't just find them used, even if bargains sometimes come up on Durst enlargers themselves. Of course, anyone with some machinists skills could simply make one in this day and
age of CNC etc. With patience I could do it simply with a basic industrial drill press. The trick was
to find the right kind of glass - different AN pattern behave differently with different focal length
lenses, different lens designs, different film grain (dye cloud vs silver particle etc). .. a little more
forgiving with 8x10 because there is less magnification of the minutiae, of course.
Ooops ... error... I should have said it was a six figure system, not seven. Still astronomical. And his
favorite enlgr lens would probably resell ten grand easy. But I personally believe just too much MTF
complicates things because you again start picking up nonessential information exterior to the image
itself, like miniscule flaws in the glass or microscratches in the mask etc. But nobody is going to confuse this kind of output with digital, that is, not once they see it in person. I don't know if I'm
going to install another Durst or not. My biggest color enlarger is twelve feet tall.
Yeah I remember reading about his monster Apo-Nikkor and his Durst setup, actually his entire setup, is pretty impressive - as are his prints. I bought a print of "Blue Glacial Ice" (from an 8x10 negative) from him a few years back and it's really something to look at.
I should have probably prefaced this entire thing in the context of black and white silver printing.