How to accurately measure the F-stop opening ?

[GeorgesGiralt]

Hi !
I own a Symmar 210/370 mm f:5.6/F:12. I had it on a Compur Electronic size 3.
This shutter is too big for my MPP Folding.
I have a Compur Electronic size 1 for it.
I have to adjust the iris opening to fit the 210 mm.
I know I've to measure from the front of the lens, lenses in place.
But how in order to be precise ?

 

[Ole]

The cells will be the same, so will the cell spacing. So if you measure the physical opening of the aperture in the old and new shutters without the lens cells in place, they must be the same at the same f-stop!

 

[epatsellis]

more importantly, any chance of you getting rid of your unwanted shutter?


erie

 

[GeorgesGiralt]

more importantly, any chance of you getting rid of your unwanted shutter?


erie

Humm ! No!
I like the Compur Electronic.
Currently the size 3 is at the repair shop because it works ok if you arm it in normal position. If when you arm it it is pointing down, when firing it, you will only get 1/250 speed, whatever position you fire it !
Last but not least, I've recently bought a Sinar Norma, so I'll be able to use the Size 3 more easily !