F-stop at No.2 Folding Pocket Brownie

Erik Hartmann

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• Jan 29, 2008

• #1

I have an old No.2 Folding Pocket Brownie.... On the lens it is marked 1..2..3..
What is that compared to 'modern' F-stops.....

Niels-Erik

 

Ole

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• Jan 29, 2008

• #2

It's marked in "AN", which is short for Arbitrary Numbers. That seems to have been one of the most common systems in use throughout history (except for Germany, where they used four different - but very precise -systems).

Assume that one value corresponds to one stop, and wing it from there...

Hint: If that's one of the ones with a Rectilinear lens (two cemented elements at each end), wide open will correspond to f:8. Or sometimes f:6.8...

 

athanasius80

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• Jan 29, 2008

• #3

I vaguely recall that 1 is f8, 2 is f11, 3 is f16, and 4 is f22, but I'm at work and my antique Kodak manuals are at home...

 

Whiteymorange

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• Jan 29, 2008

• #4

In my experience, with a Pocket Premo, the equivalent stops are more like f16, f22 and f32. This thread goes into more depth.

 

OP

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Erik Hartmann

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Sep 25, 2006

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• Jan 30, 2008

• #5

Thanks to Your all..... Now I can use a 'modern' lightmeter to get some better old pictures.....
And the camera is working very well....it might be about (or nearly) 100 years old..It is the exportversion for England.....

niels-erik

 

crabby

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• Jan 30, 2008

• #6

http://www.brownie-camera.com/tech.shtml