[largeformat] Introduction of 10" WF Ektar

[Les Newcomer]

I've been trying to find out when the 10" WF Ektar was announced to the 
world.   I always thought it was a by-product of the WWII Metrogon,  
with early intro in '46 and wide distribution in '47. (at least that's 
true with the 135 and the 80mm and always assumed that the whole series 
came out pretty much together or within a year of each other)  but a 
friend just pointed out to me that Ansel's picture of Steichen? 
Steigliz? in a tree, is labeled as shot with a 10" WF  Ektar in 1940.

Could Ansel have shot with an experimental lens?  or worse yet for my 
theory, a production lens?

Les Newcomer