Question about leaf shutters

[Zenmervolt]

I recently picked up a Yashica Electro 35 GSN and am looking forward to playing around with a rangefinder, but I have a theoretical question about the type of shutter that rangefinders use.

Rangefinders typically use a leaf shutter and the GSN uses a pretty standard stepless Copal leaf shutter. However, my question is how does a leaf shutter avoid having the center of the image always be more exposed than the edges? As best I can tell, the center of the image is the first part of the leaf shutter that opens and the last part that closes which means that the center is always open for the longest period of time. Is this simply a case of the leaves moving fast enough that it doesn't matter in practical application?

The camera, of course, is working fine, I'm just interested in a theoretical manner.

ZV

 

[corkyg]

My rangefinder camera (Leica) has a focal plane shutter. I had a Kodak 35 with a leaf shutter. F/Ps can be much faster. I haven't run into a leaf with a speed much above 1/500th. I learned on an old Kodak 35mm with a leaf - not even a rangefinder. That was done by personal estimate, usually helped by a good DoF.

 

[Zenmervolt]

The fastest leaf shutter I've seen was on the Yashica Lynx 1000, as the name suggests it would manage 1/1000 sec, but yes, most max out at 1/500.

You're right that I should have said that it's the type of shutter typically used on fixed-lens rangefinders though. The Leicas have interchangeable lenses IIRC, which would make them poor candidates for leaf shutters, which are typically built into the lens itself and would therefore add a lot of cost and complexity to interchangeable lenses.

Still doesn't answer my theoretical question though.

ZV

 

[corkyg]

This discussion has some possible clues to your question:

Leaf

 

[Zenmervolt]

Originally posted by: corkyg
This discussion has some possible clues to your question:

Leaf

Very interesting discussion! Thanks!

ZV

 

[ElFenix]

partly, i think, because the shutter is in the lens rather than behind it. and partly because of the slow speeds that you're using (but it does get inaccurate at short speeds). the amount of time difference is not much when it's open at 1/60, but is more significant at 1/500th. so, yes, in practical application the leaves move fast enough at most speeds that the difference doesn't amount to much.