450-480mm lens for 12x20

Jarin Blaschke

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Hi all:

I have slowly been building a 12x20 kit, and have almost everything I need, except a shorter focal length. My eyesight is still very good and combined with my mild OCD, I'm after sharpest performance and most pleasing tonality. I like to fall into a perfect photograph. I can see diffraction after f/64 on my 8x10 chloride contact prints, and I'd like to protect for 4x enlargement for 12x20. In 8x10 I almost always shoot between f/22 and f/45 for maximum sharpness with Apo-Sironar S lenses. Yes, I know that technique is foremost - I work on this all the time. I know that I'll have to get adhesive holders and print with a vacuum frame to see the difference.

For this new format (12x20) I have so far accrued a 600mm Fujinon A and a 750mm Zeiss/Jena Apo-Germinar.
I also purchased a 480 Symmar S, but I found it doesn't quite cover 12x20 due to mechanical vignetting. I'll have to sell or trade toward something else. Three lenses come to mind:

450 Nikkor M - This well regarded lens is reputed to cover 12x20 at my preferred apertures (/22 to /45). However, it's a Tessar, which by reputation has less coverage and less even performance than a plasmat. Any remarks?

480 Apo-Symmar L. My Symmar S from 2 generations prior doesn't cover, but perhaps this later lens does? Obviously very expensive, but I'm happy to wait and save and buy once.

480 Apo-Sironar N? Does this cover? How does it stack up if I'm used to the S series?

Are there any other lenses to consider?

Thanks!
Jarin
 

Lachlan Young

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Regarding the 480mm plasmats, I suspect they'd cover the format if the mechanical vignette can be removed - which is probably really there to prevent flare issues on 8x10 from the huge coverage (I recall the angle of view suggests an approximately 700mm image circle - the Apo Sironar S design suggests that it would have been about 50mm larger in coverage if they'd ever made a 480 in that series). Compared to re-barreling a cinema lens, it's probably fairly straightforward.
 
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Jarin Blaschke

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Hmm. Are you implying that it could be done?

Jarin
 

Lachlan Young

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Jarin Blaschke said:
Hmm. Are you implying that it could be done?

Jarin
Click to expand...

If it's the mechanical barrel dimensions/ something inside the barrel that's restricting it - and not something to do with the shutter assembly (and even then, I reckon it could be persuaded into a #5 shutter), then I don't see why not. The optical design doesn't seem different from the others in the range & I recall that the 360mm has only fractionally less stated coverage (and I think some 360 plasmats will cover 12x20 stopped down). What has always struck me as odd is that the 480 barrel has always looked disproportionately long compared to the others in the range. Maybe worth asking SK Grimes - I'm almost more surprised that no one has explored de-limiting the lens coverage before. Obviously there are no guarantees of optical performance out towards the edges.

Two other lenses you might want to keep an eye out for are the two longest focal lengths in Wollensak's Velostigmat 1a/ Raptar 1a series - they're claimed to cover 12x20 stopped down (presumably f45) - again, usual disclaimer about how well they will/ won't perform if taken bigger than contact print. I have the 330mm model which is supposed to cover 11x14 (haven't tested that).
 

Dan Fromm

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Hmm. A 450 that covers 12x20 (diagonal 592 mm, please correct if I'm mistaken) has to cover 67 degrees. 480, 63 degrees. A 19"/480 mm f/6.3 tessar type would just do it without movements. Dagor type, as I pointed out above, ought to do it with some wiggle room.

The real problem is that formats much larger than 8x10 pretty much went away some time ago, and with them went the market for lenses that cover them.
 

Lachlan Young

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@Dan Fromm - Do you know if Wollensak ever made claims for the intended angle of view coverage of the triple convertible Velostigmat/ Raptar 1a's? All I can find are their claimed format coverage sizes - and I have better things to do than try and see what the maths suggests those angles might be.
 

Dan Fromm

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I have no idea and I have better things to do than pore through https://alphaxbetax.com/wollensak-lens-and-shutter-compendium/ to find out what Wollensak claimed for the lenses.
 

5x7shooter

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Our of curiosity, I decided to do the research and math about whether any Wolly 1a triple convertible would cover 12x20.

The 1914 and 1916-1917 Wollensak Velostigmat catalogs at PacificRimCamera.com both list the Velostigmat Series 1 No.6 lens, as the longest focal length of the series. It is listed as 16 inch focal length ( about 406mm), at f/6.3 and claimed to cover 11x14. Shorter focal lengths are listed consistently as normal angle of view or slightly wider on their respective film sizes. For example, the 6" / 6.3 version is shown as covering 4x5, the 7" as covering 5x7, 9.5" covering 6.5x8.5, and the 12" version as covering 8x10 but then Wollensak elsewhere claims an 85 degree angle of view,

With a 12x20 diagonal of about 580mm (23"), a 16" lens would need roughly a 71 degree angle of view to just cover 12x20. Given the relative rarity of that Wollensak lens, estimating by analogy may be about all that's feasible.

Bausch and Lomb made the Double Protar VIIa, a similar triple convertible lens.. B&L's 1904 catalog recommends using a 55 degree angle of view focal length, which may very well just be the convention for a "normal lens" angle of view. B&L then goes on to describe a very large "image circle" that's about 1.75X the focal length. That works out to just over 82 degrees, very similar to Wollensak's 85 degree claim for the Velostigmat 1a,

Although those alleged angles of view more likely describe the angle for the circle of illumination, testing some shorter length Protar VIIa lenses does suggest that they have a useful 70 degree angle of view, with a 5.5" combination covering 5x7 with at least some corner sharpness remaining.

So, it's quite possible that the longest available Wollensak 1a , the 16" No, 6, or a comparable Zeiss/B&L Protar VIIa, might illuminate the corners of a 12x20 film but no guarantees on corner image quality.

Dan's suggestion to check out a Dagor in the 450-480mm range is likely to be more predictable and reliable, and hence likely the better way to go.
 
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JensH

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Hi,

comparing lens sections of the Apo-Symmar's 360 and 480 (both around 500mm ic) it looks as if the glass elements of the 480 are simply restricted (cut down) towards a diameter not causing problems with 11x14".
Altering the barrel (metal) wouldn't help a thing... as you suspected.
The latest Apo-Symmar-L 480 gives the same 56deg angle as the Symmar-S..., even the filter size is the same.
Sure there is the Schneider XXL 11/550 but no 450 to 480mm lens by SK or Rodenstock.

Best
Jens
 

138S

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Jarin Blaschke said:
450 Nikkor M - This well regarded lens is reputed to cover 12x20 at my preferred apertures (/22 to /45). However, it's a Tessar, which by reputation has less coverage and less even performance than a plasmat. Any remarks?
Click to expand...

You require a near 600mm circle for this format. The Nikkor-M Image circle (f/22) is 440mm, recommended (10" x 12").

Probably the M has a way larger image circle, so it may used beyond 440mm if the corners are out of focus, or not important, or we tolerate the flaw... but by no means it is a 12x20 lens, still many used it for 12x20. For a contact copy we may we quite happy if the lens delivers only 6 lp/mm in the far corners !!!

A tessar design cannot correct all perfectly at the same time because the element count is not enough, the main sacrifice the Nikkor M design makes is field curvature, but this may not be important if lens is well stopped or not used in architecture.

______________________________________


The Fujinon CM-W 450, at nominal 550mm circle, for 12x20" we only use one inch in each corner beyond the nominal rate.

______________________________________

You may also explore the ancient B&L 14x17 Series IIB, which is a 489mm Tessar, reportedly.


 
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138S

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TheFlyingCamera

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I use my Nikkor 450M on my 14x17 even at relatively large apertures (f/22, f/16) with no apparent issues, but I contact print in palladium, so that may be masking some of what you're talking about. It used to be a "bargain" lens for the format, but these days they're going for around $1K each. Another lens, albeit shorter than what's being requested, is the Schneider 355 G-Claron. That will cover 14x17 or 12x20.
 

138S

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TheFlyingCamera said:
I use my Nikkor 450M on my 14x17 even at relatively large apertures (f/22, f/16) with no apparent issues, but I contact print in palladium
Click to expand...

Well, not much ULF enlargers are out there...

Recently all we got atonished by that 450kg/630kg 20x24" enlarger made by Jürgen Heiland for Art of Foto, St Petesburg (RU)




But IMO a major motivation to go to ULF is enjoying the alternative contact printing purity, if wanting a larger print then more wood is spent for the next camera...
 
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Lachlan Young

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I'd agree with this analysis in general - it's the age-old problem of the angle the lens will illuminate to, vs the angle it has some resolution at, vs the angle it has adequate MTF at that'll withstand a 4x enlargement. Has anyone ever MTF tested a Protar/ Wollensak 1a? It is striking that convertible lenses went pretty quickly (or went to asymmetric designs) about the time that computer design based around MTF theory/ testing started to become a dominant means of designing/ testing optical performance.


That's a pity, but not surprising, going by how heavy the 480mm plasmats apparently already are
 

5x7shooter

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Anecdotally, on triple convertible Protar VIIa lenses:

To briefly summarize my late September 2020 post #142 to the "Thinking about getting an 8x10" thread elsewhere in this forum, I recently did comparison shots with five uncoated Zeiss and B&L Double Protar VIIa lenses, 145mm, 165mm, 183mm, 254mm, and 300mm. Having just acquired the 10" Protar, I was curious about how triple convertible Protar VIIa lenses compared with their modern equivalents.

All lenses were in very good condition. There was no visible damage nor optical issues except some minor edge separation on the 300mm and a minor scratch on the 254mm. Neither affected images.

I compared each Protar VIIa lens to a modern equivalent focal length Fujinon NWS or G-Claron Plasmat-style lens and some other. modern lenses. I did not test MTFs or try to derive resolution numbers but instead did a rank-order comparison by taking photos of the soft foliage of Eastern White Pine needles, a practical test of a low-contrast, highly detailed subject. A few weeks earlier, I also did some photos of an archetypical flat wooden fence with resolution targets attached center and edges..

Generally, the modern Plasmats were consistently sharper and with better contrast than the equivalent Double Protar VIIa. I had hoped for a better showing by the Protars as I have always had a certain fondness for them. I own 5.

Given the reputed difficulty and cost of properly assembling and centering a triple convertible lens's 8 cemented elements, it's no surprise that more easily assembled 6 element Plasmats had a cost advantage once lens coatings were perfected. Modern Plasmats also seemed superior optically and with better coverage.

The idea of a triple convertible lens was beguiling in the contact print to 4X enlargement age, but the individual groups are basically Rapid Rectilinear lenses without any air space. That doesn't work well for any degree of enlargement in the modern era.
 

5x7shooter

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A bit of an update on triple convertible Protar VIIa coverage: In his mostly technical book "Examples", Ansel Adams mentions that he used a 145mm / 5.5" Protar as a wide-angle lens on 5x7 when making one of his famous Canyon de Chelly photographs. That approximates a 73 coverage angle on 5x7 film.
 
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Jarin Blaschke

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Jarin Blaschke

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So, a 450mm Nikkor M is on it's way to me from Japan now. I'll see how it does at f/32 to /45, my preferred aperture range for crisp landscape work. From numerous accounts of that lens, 12x20 will be illuminated - the question is whether corner sharpness will hold at x4 enlargement. I shall report back when I have results to share. (I'm shooting a movie abroad at the moment so probably early next year)

I haven't sold the 480mm Symmar-S yet. Is the consensus here that the 480 Apo-Symmar L probably wont cover any more than it's older brother? Nor will the Sironar-N?

I could hunt down an XXL 550 perhaps, but as I have a Fuji A 600mm, not worth the obscene cost.

Jarin
 

Oren Grad

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I have both the 450 Nikkor-M and the 480 Sironar-N. The 450 Nikkor-M serves as the standard lens for my once-in-a-very-blue-moon tinkerings with 12x20. I don't think the Sironar-N will cover, but I've never tested it and probably never will, because the thing is monstrously big and heavy. I wouldn't dare put that kind of load on the front standard of my F&S for fear of destroying it. The Nikkor is small and practically weightless by comparison.
 

138S

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Jarin Blaschke said:
I know that I'll have to get adhesive holders and print with a vacuum frame to see the difference.
Click to expand...

You may convert any regular holder to adhesive holder by using 3M Re Mount spray glue in the septum of the holder, a mask can be used to protect what you don't want glued, with those big negatives ensuring flatness may not be easy. Also the center only of the holder can be sprayed, also by using a mask.

If using that way you may protect the glued area with a mylar (etc) sheet, or with a discarted negative to protect the glued area until you load another sheet, of course from time to time the glue has to be renewed by spraying more or by carefully cleaning the glue with a suitable solvent and adding new.

_______

By f/45 diffraction limit is 35lp/mm

Chris Perez found this particular rating of the Fujinon C 450 with TMX (That C covers 486 nominally, the M 440)

f/16 54 54 54 (center mid corner)
f/22 54 54 54
f/32 38 33 38 https://web.hevanet.com/cperez/testing.html

It has to be noted that that Perez test was on 4x5, taking the very center of the circle 486mm circle, for that reason center-mid-corner are mostly equal, of course in the ULF corners that will vary, and perhaps the balanced optimal aperture should be slower.


Regarding the center, at f/32 diffraction limit is a superior 50lp/mm (than the 38), but at 50 this is total extintion and while the limit is 50lp/mm f/32 diffraction degradates performance from 54 to 38 at f/32, of course depending on the scene (DOF) stopping more may deliver better yield, one thing is shoothing flat targets an another one is real photography.


Jarin Blaschke said:
and print with a vacuum frame to see the difference.
Click to expand...

The vacuum frame can be substituted by just a thick glass, say a 10mm or a 15mm one, the glass weight is enough to ensure flatness, you always may use a thicker glass. Under paper some foam will provide a perfect adaptation, I use Armaflex bare insulation foam, today widely used for van camperization insulation, it has a nice visco effect, softer foam may also be good.

Also important is light "collimation", if the contact print exposure is illuminated by an enlarger focused then rays don't cross one with the others, so it helps to ultimate fidelity.

BW papers are able to record 60 to 100 lp/mm at high contrast, you may contact print an USAF 1951 glass slide to see the effects of pressure and collimation effect.

In contact prints we may want to go well beyond what the naked eye can see, perhaps it's a kind of sickness (!) but exploring a well crafted contact print with a powerful magnifier is pure fun, one may spend hours with the magnifier discovering new detail, that's sharp even at x8.



It would require a 71.5º coverage, but... was the negative cropped for that final print ?

AA croped the negatives many times, like other famous artists (Dorthea Lange, Steiglitz, Avedon, Newman, Penn, Weegee...).

If it was the case perhaps coverage was not that... we don't use LF zooms, if we have a composition, a point to shot from, and fixed focal then we crop... or not...
 
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