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Craig Wactor
26-Aug-2005, 16:19
Anyone know of a cheapish lens around 300mm that would cover 11x14? A barrel lens would rock. I don't have the money to put into an APO-Sironar.

John Kasaian
26-Aug-2005, 17:05
Craig,

A 300mm Dagor would work, so would a 14" Commercial Ektar. Niether are real cheap but if you find one in the barrel it should be considerable less. If you care to go for a 19 incher contact me---have I got a deal for you!

You might also find a 305 G Claron or its Rodenstock twin or maybe an Eskofot in barrel (I'm SWAG -ing here), though I can't say how they'll cover 11x14 (I'm pretty confident the G Claron will)

Good luck!

Christopher Perez
26-Aug-2005, 17:05
Schneider's 305mm GClaron would work. I don't know how much they might cost in barrel. But in shutter I wouldn't pay more than $500US.

There are some GClaron knock-offs made by Rodenstock which might work. I forget what they're called. They seem to sell for not much money.

Also look for 270mm GClaron f/9 in barrel. Or there's a guy on the auction site who is moving a bunch of 355 GClarons in barrel. All should be less than $500US.

Kodak Commercial Ektar 14 inch f/6.3 have been reported to cover the format. These can be had in cheap in working shutter.

Perhaps this'll get you pointed in a starting direction?

Christopher Perez
26-Aug-2005, 17:08
Dagors. Those would work in barrel.

In fact, I have a barrel mounted 270mm Dagor knock-off (Kenro?) that we might be able to reach a very attractive deal over. I'd forgotten about this when I posted my first comments on the topic.

e
26-Aug-2005, 17:37
I have a Nikkor 240mm f10 process lens that I had planned to put in a shutter that couldn't be accomplished at SK Grimes. The lens is new/unused with flawless elements but has a mark or two on the barrel from SK Grimes repair shop. The lens is unbelievably sharp at all apertures including wide open. I have two of these lenses, I'm keeping one of them. The other I'm selling for $195.00 when it arrives next week. This lens is sharp all the way out to the corners of my 7x17(even wide open) with extremely even illumination. Stops down to f32. These lenses start at about $345.00 on the auction site. Emile/www.deleon-ulf.com.

Scott Rosenberg
26-Aug-2005, 21:31
i'll secong chris's suggestion for the 305 g-claron... great lens, great coverage - don't let the single coat only issue deter you. it's a wonderful optic and not prone to flare. clean samples in late, all-black shutters, are going for around $600 now, but they are wll-worth it!

scott

Jan Van Hove
27-Aug-2005, 03:59
My own solution to the "300mm-covering-11x14" problem is a Rodenstock Apo-Gerogon 300mm f9 process lens. It covers 11x14 and a little more, though misses the corners of 12x20, when wide-open...

It's a process wide-angle lens, one of those that can be bought for cheap these days...

But the 305 g-claron sounds good also...

PJ

robert_4927
27-Aug-2005, 04:03
14" blue dot trigor....amazing lens and it covers my 8x20. there's one on epay right now

Michael Jones
27-Aug-2005, 10:59
Cheap (relatively):
old 300 mm Dagor in barrel or
Emile's Nikkor

Moderate:
270-305mm G Claron;
14" Ektar; or
355mm Schneider Symmar (any version)

More than moderate:
240-300 mm Dagor in a shutter or
355 mm G Claron

Good luck.

Mike

Jason Greenberg Motamedi
27-Aug-2005, 12:56
If you want a cheap 300mm, look for a Rodenstock Apo-Gerogon, Eskofot (or Staeble) Ultragon, or the Agfa Repromaster (AKA Intergon) repro lenses. All of these will cover 11x14. If you are willing to spend more, the G-Claron or the Graphic Kowa also cover and fit directly into shutters (copal 1 and copal 3S respectively).

Oren Grad
27-Aug-2005, 13:05
One thing to keep in mind is that the Rodenstock Apo-Gerogons are reputed to be difficult to mount in shutter. That's fine if you only ever intend to use them in barrel, but not if you're thinking of buying a lens in barrel now to save money and then later on having it mounted in a shutter. I don't know about the Ultragons or Repromasters, but as Jason points out, it's generally not a problem with the G-Clarons and Graphic Kowas.

Scott Rosenberg
27-Aug-2005, 15:21
from Richard Knoppow, "It is [14" Blue Dot Trigor] essentially a adaption of the Dagor as a copy lens. I
suspect the high prices come from either a misunderstanding of what it is or perhaps simply because it was not made in large quantities.

if you can find one, a better option to the trigor would be the Schneider 14" Gold Dot Dagor.

good luck,
scott

robert_4927
28-Aug-2005, 06:19
The blue dot out performs the dagor hands down as far as sharpness goes. It covers like a dagor and is almost as sharp as an artar. As far as lens element construction maybe someone more qualified could give you a better assessment than I. But as a photographer with a lupe in my hand I can show you significant differences. It is an amazing little lens. I've owned a gold dot and currently own a 16.5" dagor and they don't even come close to the blue dot as far as coverage vs. sharpness. Like I said, covers like a dagor but is as sharp as an Artar. I've heard them called triple dagors and I don't know if that is because of the element design. There is not much info on them that I can find. I've talked with Richard and the only thing that he can find on them is that it was a W.A. process lens and most of them were produced by Kern. (Swiss made). My lens collection consists of 24" artar...30" artar....16.5" dagor....they will all go before the 14" Trigor goes. They will have to pry the Trigor from my cold dead hands.

robert_4927
28-Aug-2005, 07:55
I would like to see an exploded view of the Trigor vs. an exploded view of a Dagor just to see the design differences. It seems ( and I could be wrong) that there is an extra lens element in the Trigor that the dagor doesn't have. O.K. you lens junkies elaborate for me. Help me out here

Jason Greenberg Motamedi
28-Aug-2005, 09:06
According to Richard Knoppow at http://medfmt.8k.com/mf/lflenses.html, the Trigor layout is the same as the Dagor:

"[The Trigor is] a Dagor. Evidently a variation of the Wide Angle Dagor with coverage larger than a Dialyte type process lens but not as wide as a Dagor. The image circle is reduced probably to reduce some of the zonal spherical aberration characteristic of the Dagor and similar cemented meniscus lenses. The Blue-Dot, also sold as the Trigor, is not an apochromatic lens. Its a good achromat. Symmetrical lenses, like the Dagor have inherently no lateral chromatic aberration when the whole optical system is symmetrical (i.e., at 1:1) and good cancellation even up to infinity focus. The Trigor was made for wide angle use in making lithographic masters. As for pictorial lenses, the Plasmat type offers better correction and easier construction due to having two less cemented surfaces. Once effective anti-reflective lens coatings became economically available, the all-cemented designs, like the Dagor disappeared since air-spaced designs, like the Plasmat offered a better solution to performance. Most modern LF lenses, copy machine lenses, enlarging lenses, are of the Plasmat type. Goerz evidently did not make Blue-Dot or Trigor lenses for long or in large quantity. They appear to have been made in only a limited number
of focal lengths..."

Steve Hamley
30-Aug-2005, 14:42
Folks,

Re: Blue Dot Trigor and Gold Dot dagor (Kern). This thread from rec.photo.equipment.largeformat may be interesting. Of all the folks I'd trust, it would be Steve Grimes - here's one of his posts from December 16th, 1998:

http://groups.google.com/group/rec.photo.equipment.large-format/browse_frm/thread/28ea2de6e68d4e9c/aaca9c1040328484?q=trigor&rnum=11&hl=en#aaca9c1040328484

Steve thought they were identical. I suspect they are with a couple of exceptions, maximum aperture and perhaps cell spacing. Oh, and the Trigor cells will not screw into the Dagor's shutter. There's a story there somewhere.

I've had the good fortune to have a 14" Kern Dagor and a "loaner" 14" Blue Dot Trigor (also Kern) in barrel.

The groundglass images appear identical at the same aperture, and I've spent time looking at various subjects in various lighting. As far as film goes, the weather here in the Tennesse valley has blown big time since I received the Trigor, but I hope to do some image quality tests soon. The sharpness tests I could do without magic light and used a drive in movie theater booth with various printed matter in the windows as a test subject. Under magnification, I could tell no difference at all in the sharpnessof the neagtives in trying to read print of different sizes. Tone and quality are indistinguishable on the GG and on the negative. I will do some more sharpness testing as weather and schedule permit.

At first I thought the Trigor was producing an image sharper than my 14" Kern Dagor on the GG, but then I realized I was looking at the GG with both lenses wide open which is f/8 for the Dagor and f/11 for the Trigor. Stopping the Dagor to f/11 produced an identical GG image. BTW, the iris in the Trigor's barrel does not open up to the barrel diameter. It seems reasonably clear in shutter it would be f/8 which I suspect is really f/7.7).

Robert, were both the lenses you were comparing (14" Gold Dot Dagor and 14" Blue Dot Trigor) Kerns (Swiss)?

Steve

robert_4927
30-Aug-2005, 23:11
The lenses I compared were my 16.5" dagor to the 14" trigor. Both lenses were stopped down to f32. I examined the negative and the print. The trigor was significantly sharper out on the edges than the dagor. I was using a 10x lupe to examine with. But even without a lupe it can be seen as sharper. Now considering the 16.5" image circle is so much larger than the 14" makes it even that much sharper because I'm looking at the 14"ers image circle closer to it's edge. Please correct me if I'm wrong. I don't have a 14" dagor to compare it with but i do know someone who does and I will do a comparison to that in the near future.Did you shoot any test shots and compare the negatives and the prints or are you just going by what you see on the ground glass? I used both lenses on my 8x20 so I was pushing the limits on the coverage of the trigor and it is still sharper than the Dagor. Now I'm not a lens expert by any means but my Dagor has much more bokeh than my Trigor when testing this way. My test were done in studio under a couple of 2000 watt Mole Fresnels.

robert_4927
30-Aug-2005, 23:35
I forgot to mention that with movements i was able to get closer to the edge of the image circle of the 16.5". It might make a difference on what size camera you are using when you conduct your tests. You may want to use a few movements to actually see the edges of the image circle. The difference may be a lot less noticable on an 8x10 GG with both lenses centered, considering you have tons of movement with lenses this size on 8x10. I will try the same tests with my 8x10 and see what I get. But I think the 8x20 allows me to see the edges of the image circle a little easier than the 8x10 will. What size camera are you using?

Steve Hamley
2-Sep-2005, 05:35
Robert,

I shot negs and used an 8x10 camera. I plan on further testing, probably this weekend, and will post results. Thanks for the info!

Steve

robert_4927
2-Sep-2005, 05:50
Steve, It will be intersting to see/ hear of your results. Keep in mind I'm comparing an early 16.5" Dagor..American Optical to the Trigor. It will be intersting to see if Kern just changed the cosmetics and they are in fact the same lens. What makes me think they are not is from what I hear the Dagor has a little more coverage than the Trigor. This was explained to me as to why the Trigor is a little bit better corrected than the Dagor which reduces the image circle somewhat. This is in line with my results. It would be nice if you could compare an early 14" Dagor with the Kern Dagor and the Trigor. Keep me informed

robert_4927
2-Sep-2005, 06:06
Steve, Try to do a few shots with extreme movements to catch the edges of the image circles. With every Dagor I've owned they didn't get real sharp until f45. This is why I shot at f 32 it showed the beautiful bokeh of the Dagor out at the edges. You'll find whatever the results you have two great lenses there. Have fun with it. It would also be interesting to know if the Kern Dagor has the two less cemented surfaces that Jason was referring to. I think Jason was saying the Trigor was of this type on construction. ( two less cemented surfaces). Could the Kern Dagor and the Trigor be the same Lens? Jason what do you think? Or are there any others out there with experience with both lenses?

Steve Hamley
2-Sep-2005, 08:08
Robert,

They have the same reflections so I'm pretty sure they're the same construction. One concept I've floated is that in the larger formats, process lenses optimized for close distances may be or appear to be sharper than normally optimized lenses. I read somewhere that Artars were optimized for 1:1 in barrel and 1:10 in shutter, so maybe it's a safe assumption that the Dagor/Trigor differences are similar. So let's say I shoot something with a foreground object, a "near-far" shot as we say in landscape, and the object image is 1/3 the 10" length og the GG, or about 3" in round numbers. That would equate to a 30" object on 8x10, far larger than anything I'd normally use as a foreground object. So anything smaller than 30" reproduced as a foreground object would reasonably be sharper with a close optimized lens.

In other words, we don't think of "macro" as such as being an object 80" x 100" (1:10 on 8x10), but anything smaller fully reproduced on 8x10 would seem to increasingly favor a process lens.

Steve

robert_4927
2-Sep-2005, 09:08
Like I said I'm no lens expert. But I don't see how a shutter would have any thing to do with the optimization of a lens. Maybe some of our very knowledgeable people here can offer some imput on these optics. About all I can offer is I shot both the Dagor and Trigor under the same lighting conditions and at the same f stop. Using movements to find the edge or near the edge of the image circle. In examining the negative and the print the Trigor was significantly sharper near its edges than the Dagor was. Granted they are both great lenses. I just think the Trigor may be a little better corrected for spherical abberation is why it is a little sharper. Like I said I have a friend with a 14" Dagor but I don't think it is a Kern Dagor. I will test it as soon as possible against the Trigor to see how much more coverage it has compared to the Trigors coverage. And also examine the edges of a few negs shot with both lenses again under the same lighting conditions. We sure could use some imput from the optical experts though.....Hey! anyone out there!

Craig Wactor
9-Sep-2005, 15:18
"I don't see how a shutter would have any thing to do with the optimization of a lens"

I think it is that the manufacturer spaces the elements differently, assuming that a shutter mounted lens is going to be used for close to infinity, and a barrel lens is going to be used close to 1:1. So it is not the shutter that changes it, just that lenses in shutters are usually optimized differently by the lens maker.

John_4185
9-Sep-2005, 20:47
The Caltar 375mm covers 11x14 pretty easily. I think it's a Tessar design, but _coated_, and very sharp.

Jason Greenberg Motamedi
9-Sep-2005, 21:20
My understanding is that a Trigor is a Dagor; They have the exact same design, six elements in two groups. There isn't much more to it than this. Goerz marketed the Trigor for the graphic arts and marketed the Dagor for LF photography. Same lens, different market.

robert_4927
10-Sep-2005, 04:59
Then how do you explain the trigor being significantly sharper than the dagor shot at the same f stop under the same in-studio lighting conditions? Also the dagor has somewhat more coverage than the trigor which makes me suspect they are not the same lens. If in fact they are the same lens then how do you explain such a difference in performance?

Ole Tjugen
10-Sep-2005, 06:01
Just off the top of my head, I thought the Trigor was a reverse Dagor - like the Angulon, but without the oversize front element?

Jason Greenberg Motamedi
10-Sep-2005, 07:30
Ole, I am just guessing here, since I have never used or carefully inspected one (price is way too hight for me to rationalize), but if the Trigor was a reversed Dagor it would have a notably larger IC, but according to Robert it doesn't.

Why is it sharper? I don't know. Why is a Sironar S sharper than a Sironar N? They are both pretty much the same design, although one is tweaked for larger coverage and has different glass. Maybe the same can be said for the Dagor and the Trigor.

If you really want to know, call Lens and Repro in NYC and ask Geoffrey Iten (sp?) or Jeff Kay, they have a 14" Trigor in shutter listed for the bargain price of $1950.

Ole Tjugen
10-Sep-2005, 10:08
Jason, I'm guessing too. But the whole reason for the oversize outer elements of the Angulon is to avoid the vignetting which is what limits the IC of a reverse Dagor.

Maybe somebody could have a close look at the reflections in one, and determine if it's a +-+ (Dagor) or -+- (reverse Dagor) construction? It's tricky, but sometimes a useful skill to learn: I learned that the Leitmeyr Wideangle is an Angulon that way. The Angulon has a strongly doble-convex center element (like " (()( ") , but that is not absolutely necessary to make it a reverse Dagor.