Re: Those in between stops?

[P3D <PTWW@xxxxxxx>]

> I don't think the lens is marked at the in between stops.

You are correct, it is not.  The f/6.3 appears on the table inside
the lens cover, and in the manual.

> Here is the ENGLISH SCALE: f/1.4, 2.0, 2.8, 4.0, 5.6, 8.0, 
>11.0, 16.0, 22.0, 32.0 etc. And prior to WW2 on the Continent the 
>scale (called Continental) was: f/1.5, 2.2, 2.5, 3.5, 4.5, 6.3, 9.0, 
>12.5, 18.0, 25.0, 35.0 etc.

>You will note I have avoided the term half-stop and used in-between 
>stop. This is because by convention the Continental scale is used as 
the 'half-stops' of the English system and vice versa.

Thanks BobH for yet another of your fascinating historical perspective
stories!

>Actually they are 1/3 stop shifted,

I don't quite follow this.  What is 1/3 stop shifted from what?

Paul Talbot


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