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mylek
4-Nov-2013, 06:47
i'll like to know how the waterhouse stop system is working?
Is it starting with #1 as the reference for the lens 's aperture then halfing for 2 , etc...
I have a Voigtlander Euryscope IV #3 which is f/6 and a waterhouse stop marked #4 with it.
So should it be more or less f/11 or f/16.

Steven Tribe
4-Nov-2013, 07:10
No, I would guess that No.4 is the fourth in a set labelled 1,2,3,4,5 etc. Where no.1 has the largest aperture.
I have a full set for Euryskop IV and they follow the present F standard.
This lens is loaned out at present, but looking at a card duplicate WHS I have.
1 is F8, 2 F11, 3 is F16 and 4 is F22.
But Voigtländer did have different F systems at different periods.

Jac@stafford.net
4-Nov-2013, 07:13
There is a thread here (http://www.largeformatphotography.info/forum/showthread.php?64772-Making-m-own-Waterhouse-Stops!) about making Waterhouse stops. (I think John Waterhouse would have appreciated the capitalization.)

Diameter = (Focal Length ÷ F Number) is the way to calculate the hole size.

The link above refers to using Forstner bits to cut the holes, however they are quite expensive but the individual already had them. I find that an adjustable hole saw, even a regular hole saw on a drill press suffices in cutting them from brass. (Finesse the hole with fine wet-sandpaper.)