AM Goerz Trigor production made by Kern?

[mhayashi]

I looked up threads here and searched in Google, but no answer is obtained so far for the title question.
I’ve recently got a copal 3 sample of Goerz Optical Co. INC Trigor 14” f11.
The scale shows f11 at minimum but the aperture blades goes wider up to the limit of the lens elements,
so I suppose it’s the same f8 as the gold dot dagor 14” f8.

My sample came with the original box, dating the inspection 7/20/1970 by an inspector initialed by R.
I don’t have a sample made in Switzerland by Kern, but from what I check from images on internet, I observe the same barrel design with matt finish, the end finish being larger, inferring the Kern design.
I also have an AM Goerz Gold dot whose barrel is with glaze and the engravings on the front element barrel is indented and painted along the letters. There is no large end finish on the barrels for the AM gold dot.
The trigor sample here has no indent on the barrel, simple letterings painted.

The box and the sheet show Goerz Optical Co. INC subsidiary of Kollmorgen.
I wonder during the Kollmorgen period, if Goerz Optical Co. INC contracted with Kern to make trigor and gold dot dagor lenses, before Schneider bought Goerz Optical Co. INC.
The original Goerz lens cap is embossed GERMANY on the side, CP Goerz New York on the top.
If anyone has some insights about this topic, I’d like to know.
Thanks in advance for your reply.

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[Greg]

My 5.9 inch Gray's Extreme Angle Periscope is very similar. Also mounted in a Copal 3. Maximum marked f/stop is labeled f/14, but the iris opens up to f/10 for focusing per S K Grimes who mounted the lens in the Copal shutter many years ago.

[David Lindquist]

I looked up threads here and searched in Google, but no answer is obtained so far for the title question.
I’ve recently got a copal 3 sample of Goerz Optical Co. INC Trigor 14” f11.
The scale shows f11 at minimum but the aperture blades goes wider up to the limit of the lens elements,
so I suppose it’s the same f8 as the gold dot dagor 14” f8.

My sample came with the original box, dating the inspection 7/20/1970 by an inspector initialed by R.
I don’t have a sample made in Switzerland by Kern, but from what I check from inages on internet, I observe the same barrel design with matt finish, the end finish being larger, inferring the Kern design.
I also have an AM Goerz Gold dot whose barrel is with glaze and the engravings on the front element barrel is indented and painted along the letters. There is no large end finish on the barrels for the AM gold dot.
The trigor sample here has no indent on the barrel, simple letterings painted.

The box and the sheet show Goerz Optical Co. INC subsidiary of Kollmorgen.
I wonder during the Kollmorgen period, Goerz Optical Co. INC contracted with Kern to make trigor and gold dot dagor lenses, before Schneider bought Goerz Optical Co. INC.
The original Goerz lens cap is embossed GERMANY on the side, CP Goerz New York on the top.
If anyone has some insights about this topic, I’d like to know.
Thanks in advance for your reply.

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Did your search turn up this thread: https://www.largeformatphotography.info/forum/showthread.php?23446-Mystery-Swiss-quot-Dagor-quot&p=219075#post219075

In particular see post #2 by Kerry Thalman.

Yours is the third Goerz lens I've seen with a serial number in the range 1,100,xxx. The other two were on ebay, both 24 inch Red Dot Artars, barrel mounted, marked Goerz Optical Co., Inc, serial numbers 1,100,358 and 1,100,699. No evidence seen on either of these that they were made in Switzerland. (I've never seen a Goerz lens with a serial number between 850,000 and 1,100,000.) Kern-made Goerz lenses seem to generally have serial numbers of 2,xxx,xxx. Then at some point Schneider began to give the Dagors and Artars serial numbers contiguous with their historic series, probably starting with 13,xxx,xxx. These may have all been made in Germany.

As far as your lens cap being marked "Germany", that just tells us the country of origin of the lens cap. I have a few of that style of Goerz lens cap dating from the mid- to late 1960's to early 1970's. They are also marked "Germany."

David

[Bernice Loui]

Historically Goerz Blue Dot Trigors were wide field process lenses in barrel only. Goerz Trigors in shutter were likely a shutter re-mount at some point in the life of the Trigor.

They are excellent in many ways, small size, small full aperture, large image circle for their focal length -vs- physical size, high definition, excellent color rendition and excellent contrast rendition.


Bernice

[Hugo Zhang]

I have a 14" Trigor with No. 1100014 and both engraving on front and back are exactly the same as yours. My lens was in barrel and I had it mounted on a Compur 3 shutter.

[Bernice Loui]

Note, mounting the Trigor once in barrel to Copal shutter gains a non-round iris. Might be significant, might make zero difference. Depends on your specific image making goals and needs.

Goerz America went to Kollmorgen Corp, then Schneider to this day. Some of the Goerz lens designs were produced under contract by Kern in CH.
Notable, Schneider re-designed the APO artar to ease production and continued to offer this lens design. Rodenstock did similar with their APO ronar..

Ponder why these APO "process lenses" persisted in the market for SO many decades?


Bernice

[Drew Wiley]

Typical of later 14" Kern Dagors too, whether in Copal 3S shutter, or the very last in Compur 3. The viewing aperture was nominally f/8, but not otherwise really usable. In fact, you need to get down to around f/11 before focus shift is fully resolved and one begins entering the range of relatively acute focus, though certainly not a full image circle yet. Being designed for repro applications, The Trigors were more apo corrected than Dagors. Nice find!

[David Lindquist]

Historically Goerz Blue Dot Trigors were wide field process lenses in barrel only. Goerz Trigors in shutter were likely a shutter re-mount at some point in the life of the Trigor.

They are excellent in many ways, small size, small full aperture, large image circle for their focal length -vs- physical size, high definition, excellent color rendition and excellent contrast rendition.


Bernice

My GOC ("A Subsidiary of Kollmorgen") price list dated August 1, 1970 shows the Blue Dot Trigor available in a mechanical shutter mount. Specifically the 6" in either a No. 1 Compur, a No. 1 Prontor or a No. 1 Copal; the 8 1/4" in a No. 1 Compur, a No. 3 Acme or a No. 1 Copal; the 9 1/2" in a No. 3 Acme (only); the 10 3/4" in a No. 4 Acme or a No. 3 Copal; and the 12" and 14" only in a No. 4 Acme. Note this list does not show the 14" Trigor available in the No. 3 Copal which is what the OP has. His Copal is of the proper vintage. Interestingly this price list shows the shutter mounted Trigors have a "normal factory reduction ratio" of 1:1, the same as the barrel mounted Trigors.

A separate GOC/Kollmorgen sheet also dated August 1970 says of the Trigor Series: "Previously available only as specials on a custom made basis..." "...are now offered as a standard series..." All focal lengths will be available in both shutter and barrel mounts. And it also states that they are set for maximum performance at object-image ratio of 1:1 "but may be used at other close conjugates from 10:1 to 1:10."

David

[mhayashi]

Thanks all for your comments!
I suppose this lens was factory mounted on the copal 3 shutter at the production, the pencil marking “copal 3”.

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Tri Tran sold a nice sample with a very close serial number to mine whose box has the same pencil marking.

https://www.photrio.com/forum/threads/fs-blue-dot-14-in-f-9-goerz-trigor-in-original-box.99792/

Another barrel sample in Russia is with the serial number 22001700 is made in Switzerland on the back of the rear barrel but it’s made during the GOC Kollmorgen period, the barrel and lettering finish resembles mine except “made in Switzerland”.

https://shopozz.ru/items/184400412739-goerz-blue-dot-trigor-14--f11-large-format-view-camera-lens

Whether GOC made my sample in NY or in Switzerland is still a mystery….
Maybe all the serial numbers lower than 2xxxxxxx were still made in NY or not….

David, I missed that thread talking about the same topic. Thank you!

Sorry, my thread title should have started GOC, not AM. I can’t edit.

[John Layton]

Probably my favorite LF lens of all time...a Kern built 14" Blue Dot Trigor - which I'd first tested by taping strips of the old Agfapan 25 to various spots in an 11/14 holder...middle and edges, and I swear to you that the resulting negatives matched those from my Mandler-designed Leitz 50mm Summicron - it was that good! Also very versatile, having pressed it into service for 4x5, 5x7, 8x10, and 11x14.

About my only complaint was that it lacked a front filter thread - so I needed to cobble together a means for filter use...but a minor complaint for sure.

At any rate...I eventually sold the Trigor, and can only hope that it is still performing admirably, and in the hands of someone who can truly appreciate its stellar qualities!

[mhayashi]

Thanks John for your comment.
I will try shooting with some color transparencies.

[mhayashi]

I just found the old for sale thread which mentioned about the same topic for the record.
https://www.largeformatphotography.info/forum/showthread.php?99692-FS-Blue-Dot-Goerz-Trigor-14-in-original-box&highlight=trigor

I also found an ad in the internet archive.
60 degree image circle corrected 1:1 and usable between 10:1 and 1:10.
227151

https://archive.org/details/sim_graphic-arts-monthly_1970-07_42_7/page/n103/mode/2up?q=trigor+goerz

[SimonMaddock]

I bought a barrel Trigor 14in 7 months ago and it became an instant favourite. Not because of the sharpness but because of the general rendering. I'd love to see some sample shots from the shorter focal length versions if anyone has something to share, or even get confirmed the existance of the shorter versions mentioned in the ad in the previous post.

For anyone curious or confused I can add that the barrel is "artificially" limited to f11. The screw connecting the aperture selector ring with the aperture mechanism itself follows a slot in the barrel body. The length of the slot limits the travel of the screw and it's the only thing stopping the aperture from being fully opened. I have played with the idea of lengthening that slot but it's a little too complicated for me at the moment.

[Hugo Zhang]

I can confirm the existence of 9 1/2" and 12" Trigor lenses. They behave the same as the 14" one: sharp as process lenses and cover a bit wider than Dagor lenses.

[Drew Wiley]

I suspect the majority of Trigor lenses were simply thrown away along with their old process cameras. I've always been hoping to stumble onto a 14 inch Blue Dot in some local architectural salvage outlet where such cameras turn up from time to time dirt cheap. The coverage of the last of the 14 inch Dagors was limited by the no.3 Compur shutters they were put in. But these weren't wide angle design either, and I can't recommend them for formats larger than 8x10. The old f/7.7 14-inchers had more coverage, though probably not in an ideal sense towards the limits of the circle, although contact printers probably wouldn't see much difference.

I don't know when ULF shooters discovered the magic in the 14 inch Trigors, but do remember back when Lens & Repro in NYC began selling them at cult lens pricing.

[Hugo Zhang]

I use my 14" Trigor for more than 80% of my 11x14 landscape shots. It covers that format at infinity with sharp corners and some room to spare. My 12" Trigor actually covers 11x14 format quite well too. The only lenses that cover more are Zeiss-Dagor F/9, Protar IV F12.5 and Protar V F/18 lenses, plus some other extreme angle lenses.

I don't know much about lens design and my experience is based upon my actual use with my camera and careful examinations of my negative. Of course, there are sample variations among the same lenses.

I put a 9 1/2" Dagor lens and a 9 1/2" Trigor on my 16x20 camera, the latter has a slightly larger circle on the ground glass. Then I compared a 12" Dagor and a 12" Trigor, again the Trigor has a slightly larger circle. But not by that much.

[John Layton]

Hugo...I'd also used my 14" (Kern-built) Trigor for most of my 11x14 work. And yes, as you've mentioned - sharp at infinity with room to spare.

I'd earlier owned a 14" (Kern-built) Dagor - which I'd used successfully for 8x10, but found that with 11x14 it displayed a bit of field curvature. Possibly a sample variation - but I seriously doubt this as Kern certainly had the chops to deliver a quality product with good consistency.

[Hugo Zhang]

John,

I had the same issue with my 14" gold dot Dagor with my 11x14 camera. Used during a trip to Bryce Canyon and nearly all pictures had blurred corners. That experience taught me to use that Dagor lens only on 8x10 or smaller cameras.

[John Layton]

...speaking of using the Trigor in Bryce Canyon - many years ago I captured some wonderful 4x5 color chromes (Fuji-50 as I recall...or was it E-100? I'll have to find them) in Bryce, with that 14" Trigor. Stunning rendition - particularly of those reds in shadow...filled with sunlight reflected from below.

[neil poulsen]

I don't know if this relates, but in '88 or '89, I attended a Photo West Conference in LA and stopped by the Schneider Optics booth. They had a brand new 14" Gold Dot Dagor MC lens on display mounted in a Compur shutter. The salesperson there told me that their purchase of Goerz included a pallet of optics. They used these optics for the 14" MC lenses by coating them with the latest MC technology, and then mounting them in the best available shutter.

At the time, I thought this was pretty classy of Schneider to make that kind of a special run.

[SimonMaddock]

Zhang and Layton,

Are/were you using the 14" in barrel or shutter? I'm very curious to know what it looks like wide open (in shutter, beyond f11), if it would be worthwhile lengthening that slot in the barrel.

[John Layton]

Copal #3 Shutter

[Hugo Zhang]

#3 shutter as well. For most of my landscape shits, I use F/32 and smaller apertures anyway.

[Drew Wiley]

Kern 14 inch Dagors were limited by the mechanical vignetting of their no. 3 shutters, and by the fact that they didn't perform as well tangentially at strong tilts as plasmat lenses of comparable focal length. I've had two different MC ones, and currently have a single-coated one. With only four air/glass interfaces plus excellent multicoating, the last version probably had the highest contrast rendering of any lens of the time - frankly, too much contrast for the color chrome work I was doing - that's why I switched it out for the previous single coat version, along with the fact I prefer the Copal 3S shutter way better than the later Compur 3. It's a fine 8X10 optic for general work; but I can't imagine using it for anything larger.

[SimonMaddock]

any focus shift stopping down from wide open?

[Hugo Zhang]

any focus shift stopping down from wide open?

Not in my experience.

[Drew Wiley]

And as per the 14 inch Kern Gold Dot Dagors, there is no focus shift from f/11 down, at very little even wider open. I got in the habit of simply setting them at f/11 to begin with, for sake of focus and composition.