Series III Dagor but strange f-stops

[baachitraka]

Is it normal that it the assembly comes with f/4.x ...

I got this lens yesterday and the shutter works but not the B and Z

 

[bernard_L]

Possibly the numbers are not f-stops but relative exposure factors; i.e. going from, e.g. 12 to 24 requires a doubling of the exposure time, and not 4x as if the numbers were f-stops.

 

[Ian Grant]

No some German manufacturers used non standard f stops early on, I don't know when Goerz changed but my 1913 120mm f6.8 Dagor uses standard f stops,

That's possibly not the original shutter, the small Compounds were replaced by the Compur in 1912 but Goerz may have had stock, your Dagor is a slightly higher SN than mine (277,xxx). Mine#s also marke I, B & T for the UK market.

Ian

 

[Ian Grant]

Here's the explanation. Not as simple as I first thought.

Still seems odd that the 4.5 is actually f6.8, and the 192 is actually f45, and that the lens itself is marked 1;6.8. I have German lenses with non standard f8 11, 16 etc numbers but they are just in-between the regular number like 6.8, 9, 12, 18, 25 & 36.

Ian

 

[bernard_L]

No some German manufacturers used non standard f stops early on

I suppose the "No" is a reply to my post just above. But look at the table you posted, first and third columns. Just what i wrote.
Goerz 6 = f/7.7 (f/8, give or take)
Goerz 12 = f/11.13 (f/11)
Goerz 24 = f/16

 

[Ian Grant]

I suppose the "No" is a reply to my post just above. But look at the table you posted, first and third columns. Just what i wrote.
Goerz 6 = f/7.7 (f/8, give or take)
Goerz 12 = f/11.13 (f/11)
Goerz 24 = f/16

I meant no to the OP. The B & T don't work if the shutter is cocked

it's very odd that a Dagor from 1913/14 has this old style Goerz aperture scale and by then most Goerz lenses were in Compur shutters, I have a similar aged Dogmar and Goerz-Ihagee both in Compur shutters.as are the two similar aged Tessars. I guess Goerz were using old stock Compouns.

Goerz were selling lenses to other companies it's possible they requested the old style aperture scale. The Goerz system is similar to Dallmeyer's but they switched the modern one in the 1890's.

Ian

 

[baachitraka]

Here's the explanation. Not as simple as I first thought.

Still seems odd that the 4.5 is actually f6.8, and the 192 is actually f45, and that the lens itself is marked 1;6.8. I have German lenses with non standard f8 11, 16 etc numbers but they are just in-between the regular number like 6.8, 9, 12, 18, 25 & 36.

Ian

Thanks for the table and all the required data are there.

Lens is in very good condition and will find a nice body (9x12) or a 4x5

 

[binglebugbob]

This may answer your questions....and then some!
The scale appears to be the old "US" system....
http://throughavintagelens.com/2010/01/the-u-s-f-stop-system/

 

[Ian Grant]

Thanks for the table and all the required data are there.

Lens is in very good condition and will find a nice body (9x12) or a 4x5

You'll be surprised how good the contrast is compared to say an Uncoated Tessar, or worse still a Dialyte like a Dogmar

This may answer your questions....and then some!
The scale appears to be the old "US" system....
http://throughavintagelens.com/2010/01/the-u-s-f-stop-system/

Except the US system has a different starting point and is based on a Ross British system

Ian

 

[JPD]

I got this lens yesterday and the shutter works but not the B and Z

When you set it to B or Z you don't cock the shutter, but only use the release lever. Maybe you already know that. Interesting aperture settings.

 

[baachitraka]

The shutter may need a bit of service. I can't move the lever to Z and B is not working as it should work.

With this I have 120mm, 130mm and 168mm Series III Dagor albeit not working shutters.

Looking forward to have 180mm and 210mm but their prices are bit too high right now.

 

[Ian Grant]

Yes short focal length Dagors can be cheap, but the 120mm covers 7x5/13x18 and Half plate just sopped down. I paid £20 or £30 (x roughly 1.3x for US $) for my 120mm DAgor which may never have been mounted on a lens board or camera. The seller had 3 other lenses listed all from 1913, I think from a clearance of a camera repair shop, oddly she'd put a low BIN price on the best of the lenses

I'm doing something similar with 165mm Tessar's rather than FL I'm wanting the full apaerture range. I have a really nice 1913 f6.3, a mega rare f5.3. an f4.5 is easy but the f2.7 is expensive and rare and the f3.5 less common.

Some years ago I bought a 10x8 Agfa Ansco Commercial View from a US Photography Professor at a decent price, the camera came with a lens board for used with a 300mm Nikkor M, and 3 spares and never used Beattie screen, and its original12" Dagor (Goerz Am Opt). I was told the Dagor was useless but then he'd never tried to use it. had separation. that was dirt pushed to the edges by careful cleaning. It's a superb lens but then I don't enlarge 10x8 by much

One comment about the 120mm f6.8 Dagor is it's not as bright as my 120mm f6.8 Angulon, it's quite noticeably dimer when focussing,

Ian

 

[reddesert]

I have a very old 210mm Dagor with a similar serial number, 293nnn. It is in an odd barrel mount that would have originally been on a focal plane shutter camera (the experts at LFPF helped figure that out). It has similar aperture labeling. The f/6.8 number on the rim is a true f-stop of course. The key to understanding US and Goerz numbers is that both are proportional to 1/aperture area, and thus exposure time. But normalized differently: US 16 = f/16, while Goerz 9 = f/9. Why start at 9? Who knows! Probably they made some f/9 lens and labeled it that way, and the system persisted for a while.

 

[Ron (Netherlands)]

The scale from the Compound in the picture of the OP seems to start at 4.6 which would resemble the f 6.8 according to the list shown above by Ian. To be able to compare the lens to lenses from different makers, it mentiones its biggest aperture as the ratio focal length/entrance pupil. But for practical reasons the scale was designed such that each incremental number would provide half the luminosity - in order to do so f6.8 was converted to 4.6 on the Goerz scale. I therefore guess that the lens from the OP came in its original Compound shutter.

Not sure whether this lens would fit the lenstube of a Compur #0 (which could be had in 4 different tubes: Compur normal 27, 28 and 30mm, Compur wide 25mm:
Here's a picture with my own compound and compur shutters with some measures: https://www.flickr.com/photos/zorki_2007/50244318642/

 

[Ian Grant]

Not sure whether this lens would fit the lenstube of a Compur #0 (which could be had in 4 different tubes: Compur normal 27, 28 and 30mm, Compur wide 25mm:
Here's a picture with my own compound and compur shutters with some measures: https://www.flickr.com/photos/zorki_2007/50244318642/

It should after all the Compur shutter is essentially a Compound with a gear train rather than pneumatic slow speed controller. My120mm Dagor in a Compound does fit a Compur I've just tried, both are the same tube length so spacing remains the same..

Of course we need to clarify that it's the dial set Compurs not later rimset which use different treads. and aren't cross compatible. The Compur #0 Wide has inside tube thread diameter of 28mm, Nornal is 27m m, and the #0 no 1 tube is 25mm. The Compur #1 is 30mm and #1s is 35mm

Ian

 

[baachitraka]

Yes short focal length Dagors can be cheap, but the 120mm covers 7x5/13x18 and Half plate just sopped down. I paid £20 or £30 (x roughly 1.3x for US $) for my 120mm DAgor which may never have been mounted on a lens board or camera. The seller had 3 other lenses listed all from 1913, I think from a clearance of a camera repair shop, oddly she'd put a low BIN price on the best of the lenses

I'm doing something similar with 165mm Tessar's rather than FL I'm wanting the full apaerture range. I have a really nice 1913 f6.3, a mega rare f5.3. an f4.5 is easy but the f2.7 is expensive and rare and the f3.5 less common.

Some years ago I bought a 10x8 Agfa Ansco Commercial View from a US Photography Professor at a decent price, the camera came with a lens board for used with a 300mm Nikkor M, and 3 spares and never used Beattie screen, and its original12" Dagor (Goerz Am Opt). I was told the Dagor was useless but then he'd never tried to use it. had separation. that was dirt pushed to the edges by careful cleaning. It's a superb lens but then I don't enlarge 10x8 by much

One comment about the 120mm f6.8 Dagor is it's not as bright as my 120mm f6.8 Angulon, it's quite noticeably dimer when focussing,

Ian

For 120mm, 130mm and 168mm with camera, I did not pay more than €25 and one lens as low as €20.

Will look for nice 4x5 cameras soon.

 

[Ian Grant]

For 120mm, 130mm and 168mm with camera, I did not pay more than €25 and one lens as low as €20.

Will look for nice 4x5 cameras soon.

That mirrors my feelings and what I paid for my 120mm.

Ian

 

[baachitraka]

That mirrors my feelings and what I paid for my 120mm.

Ian

But 150mm, 180mm, 210mm etc are rather expensive or hard to see any new items in ebay

 

[JPD]

But 150mm, 180mm, 210mm etc are rather expensive or hard to see any new items in ebay

Yes, then you have the focal lengths most popular for the large format users, so sellers try to get more money out of them.

I have the 100, 130 and 168 mm Dagors. The 168 is in an empty Compur shutter, sadly. The 130 mm I have mounted on a 6,5 x 9 Avus camera, and the 100 mm is on a Roll-Tenax that takes 120-film, so I think it will stay on it. I also have a nice RÜO Iricentor 180 mm, that is a Dagor copy, and a good one. The retaining ring is stuck at the moment, like it's welded in place, so I can't mount it on a camera just yet. But I have tried it. Of the "reverse Dagors" I have a 135 mm Zeiss Doppel-Amatar and Steinheil Orthostigmat, both very good.

Then the 4,8/120 mm eight element Rietzschel Linear and a 4,5/105mm one. I have taken my first test shot with the 120 mm on 9x12, so I will see how it turns out. The 105 mm has many spots on one of the cemented surfaces in the front group, likely balsam failure (very common for these lenses), but the back group is fine. It would be interesting to test the back group as a long lens, because this was one of the selling points of these lenses, that they are better corrected than the Dagor for use as convertibles.