coupled rangefinder

[lubitel]

I am looking for a medium format RF on the bay, like Iskra or agfa super isolette. what is actually a difference between a coupled and uncoupled rangefinder? sorry for a dumb question. I thought all rangefinder systems are pretty much the same: turn the focus ring -- yellow patch moves over the image.

thanks.

 

[Fred]

A coupled rangefinder is when you turn the focus ring of the lens for RF alignment hence when the images are aligned the lens is focussed. This is the one your familiar with.

A non coupled rangefinder is when you align the RF imagees using a separate wheel then read off the distance on that wheel and apply it to the distance scale on the lens to focus it. Pretty much like using an external rangfinder.

 

[lubitel]

aha!
thanks.

have you used it and do you find it to be very inconvenient?

 

[Fred]

You still see some older external rangefinders on the used market and some non coupled cameras mainly medium format.

It slows you down a bit but the distance numbers on the RF should be the same as those on the lens focus scale so accuracy should not suffer too much. Not exactly ideal for a PS though.

 

[Solinar]

aha!
thanks.

have you used it and do you find it to be very inconvenient?

It is truly think before you shoot. If your subject is moving around, you have to close down the aperture and zone focus. Coupled RF focusing is much quicker in use.

One other consideration, both the Super Isolette and the Iskra have an automatic film stop when winding. This makes advancing the film much quicker than using a camera that relies on a red window.

Most folder do not stop the film automatically at the next frame and one must carefully wind the film not looking at their subject, but looking for the frame number printed on the paper backing of the film to appear in the red window on the back of the camera.

It's another thing to slow you down and damn near impossible to do in low light, especially with Ilford film.