Are Fujinon A's Triplets?

Gaston 012 · May 12, 2021

I was killing time browsing E Bay and came to this add of a Fuji A 300mm f9:

https://www.ebay.com/itm/1847320811...brand=Fujifilm&_trksid=p2334524.c100667.m2042

The photos show 3 aperture scales and f 550 and f 180 in different colors.
What does this mean?
I have a Fuji A in 240mm and it shows only one scale.
Thanks

AgX · May 12, 2021

Such lens can be used in 3 configurations:
-) as is
-) front group only
-) rear group only

Each configuration got its own focal length.
As the diaphragm diameters are consistent (same shutter in all 3 configuration), for each configuration the apertures vary.

AgX · May 12, 2021

Such lens is a 3-in-one lens, but not a triplet.

A triplet:
-) basically a lens made of 3 lens-elements (single pieces of glass)
-) typically it refers to a "Cooke-triplet", a triplet of destinct design. One of the most spread potographic lenses.
-) can also mean a 4 lens-element lens, if 2 of the 4 are cemented together as for instance in a Tessar-type. Then this is called "expanded triplet".

Lachlan Young · May 12, 2021

That lens has been stuck into another copal #1 shutter and not had the scale changed. Whatever was in there before was 180/5.6 and 550/16.

Gaston 012 · May 12, 2021

Yes, I know what a triplet is, I own one by Cooke, but that really was not my question, my question is: Are the A's triplets? The seller here does not seem to have realized the significance of these markings.
I have read a bit on the f 9 A's and no one has ever mention this, my 240 certainly is not maker for 3 different aperture settings.

Gaston 012 · May 12, 2021

Yes Lachlan, I think that is it, the guy that buys it will have a surprise, maybe I should write the seller.
Gaston

DREW WILEY · May 12, 2021

Fujinon A's were marketed by Fuji as "Super Plasmats", and that's what they truly are. They're not triplets. The 300A consists of six elements in four groups. They're better correctly than general purpose plasmats, but superb at infinity too. And all except the rare 600 and 1200mm are in small lightweight shutters, making these versatile for travel in the field. But Lachlan already detected the fly in the ointment in this particular instance - not the original shutter. Therefore, NO, Fuji A's themselves were never intended to be used as convertible lenses, with the front and rear elements used in isolation from one another.

AgX · May 12, 2021

I based my reply on Gaston's statement of 3 scales.
But wondered already on the focal lenghts, as such LF lenses are typically quite symmetrical and thus front and rear group would have about same focal length.

At least I am right on the rest...

reddesert · May 12, 2021

Gaston 012 said:
Yes, I know what a triplet is, I own one by Cooke, but that really was not my question, my question is: Are the A's triplets? The seller here does not seem to have realized the significance of these markings.
I have read a bit on the f 9 A's and no one has ever mention this, my 240 certainly is not maker for 3 different aperture settings.

This is conflating a triplet, a lens with 3 elements, versus a "triple convertible lens," a lens that can have 3 focal lengths: front+rear groups, front group only, and rear group only.

Steve Goldstein · May 12, 2021

The aperture scales, and likely the entire shutter, are originally from a 180mm Rodenstock Sironar. The original Sironars (before Apo Sironar and the later Apo Sironar W/N/S designations) were convertible lenses. The normal configuration of both cells screwed into the shutter is 180mm; remove the front cell and the rear cell alone is a 550mm lens.

The "0011.044" is a dead giveaway - Rodenstock used the 0011.0xx format on all their Plasmats with one exception I know of (210mm Macro-Sironar). 0005.0xx are Grandagons - wide angles.

Bob S · May 12, 2021

Steve Goldstein said:
The aperture scales, and likely the entire shutter, are originally from a 180mm Rodenstock Sironar. The original Sironars (before Apo Sironar and the later Apo Sironar W/N/S designations) were convertible lenses. The normal configuration of both cells screwed into the shutter is 180mm; remove the front cell and the rear cell alone is a 550mm lens.

The "0011.044" is a dead giveaway - Rodenstock used the 0011.0xx format on all their Plasmats with one exception I know of (210mm Macro-Sironar). 0005.0xx are Grandagons - wide angles.

The original Sironar was replaced by the Sironar N, which covered a larger circle then the Sironar. The N was replaced by the Sironar N MC which was replaced by the Apo Sironar N.

AgX · May 12, 2021

Steve Goldstein said:
The original Sironars ... were convertible lenses. The normal configuration of both cells screwed into the shutter is 180mm; remove the front cell and the rear cell alone is a 550mm lens.

What makes me wonder though is that the plain Sironar and Symmar were equivalent lenses from Schneider and Rodenstock.

Symmar:
180mm/315mm = 1/1.75

Sironar:
180mm/550mm = 1/3.1

I am puzzled... as the convertible characteristics should be similar.

DREW WILEY · May 12, 2021

Sure, anyone could simply remove a front or rear element and get something - but what would be the actual quality expectation? Specific lens design factors in all kinds of things. Lenses designed to be convertible would logically need some kind of difference. But its also true that most of them were made prior to the latest generation of plasmats, which are better corrected all around. There have been a couple of later limited runs of convertibles, namely the Wisner and pricey Cooke sets. The Wisner was not corrected for color film use without a supplementary lens. The Cooke is color-corrected.

Sironar vs Symmar vs Fuji vs Nikon. I heard some of the story from my brother who sold LF and MF pro gear at the time. My first lens was a Symmar S; but apparently Rodenstock and Fuji retooled prior to Schneider - itself a long story recited on other forums by others who know better than me - and Rodenstock came out with the better-corrected "Apo" Sironar N. I'm sure that doesn't equal the meaning of "apo" in process lenses, but was a marketing clue to one-upmanship over Schneider.
Nikon was a smaller player in the LF lens market, but keeping pace. Each brand had their own specialty lenses. But it was only a matter of time until all four of the big players were pretty evenly matched in the general-purpose plasmat lens category.

Steve Goldstein · May 12, 2021

@AgX: Perhaps Jason could chime in, but I don't think there's any particular requirement that all convertible lenses have the same ratio.

The 0011.044 number exactly matches Rodenstock's numbering scheme - I have a whole spreadsheet of these.

Dan Fromm · May 12, 2021

AgX said:
Such lens is a 3-in-one lens, but not a triplet.

A triplet:
...
-) can also mean a 4 lens-element lens, if 2 of the 4 are cemented together as for instance in a Tessar-type. Then this is called "expanded triplet".

Mehr schweinerei aus Deutschland.

AgX · May 12, 2021

AgX said:
What makes me wonder though is that the plain Sironar and Symmar were equivalent lenses from Schneider and Rodenstock.

Symmar:
180mm/315mm = 1/1.75

Sironar:
180mm/550mm = 1/3.1

I am puzzled... as the convertible characteristics should be similar.

But Sironar and Symmar seem both of symmetrical design, thus rear and front group must have about same FL.

If these lenses were true symmetrical in both cases the sole groups should have a FL of 364mm.

For the Symmar 180mm it is thus: 435mm/315mm
For the Sironar 180mm it is thus: 270mm/550mm

This shows how much one may be mislead by just looking at lens sketches.

Gaston 012 · May 12, 2021

Thanks a lot guys, I knew I would lear a great deal by , so to speak, spilling the beans on that A.

Kodachromeguy · May 12, 2021

If the Fuji glass has been mounted in a Sironar shutter, do we know if the aperture scale is correct?

Gaston 012 · May 12, 2021

If you look at the photos, there is no additional scale besides those for 180 and 550 so I am assuming they will be significantly off for 300

reddesert · May 13, 2021

AgX said:
But Sironar and Symmar seem both of symmetrical design, thus rear and front group must have about same FL.

If these lenses were true symmetrical in both cases the sole groups should have a FL of 364mm.

For the Symmar 180mm it is thus: 435mm/315mm
For the Sironar 180mm it is thus: 270mm/550mm

This shows how much one may be mislead by just looking at lens sketches.

The original design of the Plasmat type is symmetrical (and it is descended from a previous symmetrical design, the Dagor). Symmetrical lens designs have nice properties where certain aberrations are zero or very small; technically they are only zero at 1:1 when the entire system is symmetric, but in practice they are also small at other distances. I'm sure this made design easier when all the calculations had to be done by hand.

I don't think the plasmats really got popular until the postwar when AR coating came along. Later designs such as Symmars, Sironars etc relaxed the fully symmetrical nature, presumably to make other improvements; calculating power was much greater. However, each manufacturer may have deviated from symmetry in different ways. For older Symmars that are marked as convertible, Schneider recommended to use the rear cell alone. This shutter for a Sironar is marked for the 550mm cell, which I guess is the rear, but I've read that Rodenstock recommended to use the front cell of a Sironar when using only one. I've not tested it myself.

In later versions of these lenses the manufacturers stopped recommending using only one cell or engraving the shutters for it. It doesn't mean you can't do it, it just means they stopped officially saying it. Color photography was becoming more common and it wouldn't surprise me if the single groups are less well corrected for it.

AgX · May 13, 2021

reddesert said:
However, each manufacturer may have deviated from symmetry in different ways. For older Symmars that are marked as convertible, Schneider recommended to use the rear cell alone. This shutter for a Sironar is marked for the 550mm cell, which I guess is the rear, but I've read that Rodenstock recommended to use the front cell of a Sironar when using only one. I've not tested it myself.

In later versions of these lenses the manufacturers stopped recommending using only one cell or engraving the shutters for it. It doesn't mean you can't do it, it just means they stopped officially saying it. Color photography was becoming more common and it wouldn't surprise me if the single groups are less well corrected for it.

Yes, in the 90's I inquired at Schneider and they replied that from the models with suffix onwards they no longer advise using the rear group on its own, as the image quality would degrade too much.

Anyway, doing a little bit of math will reveal interesting results on gained focal lengths of single groups of those older lenses. The same can be done experimentally on the newer models where no single-group focal lenght is given any longer. In all cases then one still can establish whether the image quality is apt for the use in question.

Kodachromeguy · May 13, 2021

AgX said:
Yes, in the 90's I inquired at Schneider and they replied that from the models with suffix onwards they no longer advise using the rear group on its own, as the image quality would degrade too much.

Anyway, doing a little bit of math will reveal interesting results on gained focal lengths of single groups of those older lenses. The same can be done experimentally on the newer models where no single-group focal lenght is given any longer. In all cases then one still can establish whether the image quality is apt for the use in question.

But how will you determine the aperture to use on one of these front or rear groups? Is that lens that the guy is selling useless until someone calibrates the aperture scale?

AgX · May 13, 2021

You got the true diaphragm diameters at each step of the shutter and you got the focal lengths of the single groups. The rest is just math. You even could take just the given aperture values and recalculate them for the new focal length.
Of course you then most likely get non-standard aperture values.

juan · May 13, 2021

The shutter looks exactly like the one on my 210mm Sironar. Two scales not three. At 210, my lens is very good. At 400 or whatever the rear cell is it’s not good at all.

DREW WILEY · May 13, 2021

The plasmat name goes clear back to 1922 according to Kingslake. What are routinely marketed as plasmats today are a distinctly different lens configuration.

Are Fujinon A's Triplets?

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