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Steven Tribe
3-Oct-2011, 14:07
Now its my turn to ask for help in identification.
As part of a Studio Camera purchase (Globus - Herbst & Firl) there was a plastic bag with two large lens cell - an achromatic front cell and a rear pair in a very aparte mounting. The flange is situated at the very rear with the notches for softness in front of the flange.
Although there is an obvious candidate, I know that there were others than Dallmeyer who used this idea. And because there is no sign of the barrel, putting an A or B etc. on this is and a size number is pretty difficult. The notches are a U at the top then one V, followed by VV's and finally three VVV's. The notch on the flange is much wider.
Glass diameter is 88mm at the rear, and slightly more in the front.
The focal length is around 320mm - perhaps less (no infinity available tonight).
I have looked through the Dallmeyer candidates but can't find a suitable one with a barrel just under 4".
Any ideas/comments welcome.
Eventually I may ask about barrel lengths for "repair"!

cdholden
3-Oct-2011, 14:35
How about Ross? Hyatt?

Steven Tribe
3-Oct-2011, 15:00
I somehow don't think a Hyatt would turn up with an old Studio Portrait set from Copenhagen anno 1900!
Will check what the 4 softness markings on the Ross look like, though.

cdholden
3-Oct-2011, 15:10
I can't see them on my phone's web browser. I was just trying to think of others that used the Dallmeyer rear element turning method of diffusion.
You are probably right in eliminating the Hyatt though.

Louis Pacilla
3-Oct-2011, 16:10
Hey Steven,

It's from a Dallmeyer and A or B serial # range 60000-90000. The type with iris and SF from the front through turning barrel. At this point Dallmeyer had the SF feature turning to the left. The same direction as dismounting the barrel from the flange. So they put locks on the flanges. One of the notches was for the Flange lock and the other for the SF feature lock or barrel lock either to lock out SF or you could do three revolutions and lock the barrel in that position.


Sometime around 90.000 I would guess Dallmeyer had a light bulb moment and changed the direction of the SF to the right so at worst you tighten the barrel to flange when you engage the SF .

Here's a 3A #69735 with the lock on the flange and turn to the left. You can see the flange lock above the f8 mark. The 4A #102355 and this turns to the right so they did away with lock on flange and no notches at all. just the center mark for start.

Steven Tribe
3-Oct-2011, 16:44
Thanks Louis! I was wondering which way to turn to release the soft turn. And I thought that the big notch could be part of locking flange system so accidents could be avoided.
The flange thread is odd - I make it about 18 threads per inch.
I can work out the F and focal length in daylight tomorrow so I can put a letter and number on it. Obviously waterhouse stops will have to be a tight fit in a new barrel or they will fall out. I suppose someone ruined their iris which lead to the barrel loss.
Another lens to lend out as I don't do many portraits

Steven Tribe
4-Oct-2011, 02:03
Yes Louis was absolutely right.
Focal length 11" (by comparison with known focal length of other lenses), glass diameter, F3 and flange thread size all match up to the 3B.
Lucky again!
Could anyone give me the length of a 3B's plain barrel? - again I am lucky enough to have a half meter of suitable brass tubing!

Steven Tribe
6-Oct-2011, 04:45
Unless anyone has the dimensions of the barrel for the front turning 3B, I will have to set up an optical bench to find the sharpest distance between the front and rear elements?
The present length is a little on the long side!