Rangefinder patch size

[maclaine]

This thought just popped into my head after looking at this image of the LED framelines in the M9 titanium: http://leicarumors.com/2010/09/22/leica-photokina-day-2.aspx/.

From a design/usability standpoint, what prevents the size of the RF patch from being substantially larger than it traditionally is? I'm talking about making it the size of the 50mm, 75mm or 90mm framelines, or even the entire viewfinder window? It would prevent you from having to center the thing you want in focus and then recomposing, thereby speeding up focusing to (manual focus) SLR levels but retaining the increased accuracy of RF focusing.

I'm sure the answer is quite simple and boneheaded, but I'm just curious. Would the enormous double image be too distracting? Cause too much glare? Require too much space in an already tiny package?

 

[JayGannon]

the second rangefinder window would have to be huge for one. And personally would mess up composition for me.

 

[Pherdinand]

hehe
i asked more or less the same question here a while ago.
I got a very very simple answer.
You could never focus on everything that is visible in the finder, therefore you would always have a double image with the exception of a small portion.
This would make the composition and simple viewing even, very very difficult.

 

[ferider]

Good question. My guess it it would be hard to deal with different distortions and parallax effects of the two optical systems. In other words, they would never completely overlap, unless symmetrically built and arranged around the lens.

 

[sevo]

There have been uncoupled/accessory full-frame rangefinders early on in history, but they were no success - the early, working ones were tiny, barely bigger than the centre spot on a Leica M. Given the increasing risk of severe misreadings outside the centre spot in a larger field of vision whenever the eye is off-angle, it did not make any sense to show a distracting and potentially wrong dual image all over the frame once rangefinders got bigger and provided better eye relief.

Full-frame split-image works better and made it into some coupled rangefinders, but even that did not make it past the WWII break in camera design.

Sevo

 

[maclaine]

hehe
i asked more or less the same question here a while ago.
I got a very very simple answer.
You could never focus on everything that is visible in the finder, therefore you would always have a double image with the exception of a small portion.
This would make the composition and simple viewing even, very very difficult.

I figured this would be the case, so maybe having it the size of the entire viewfinder window isn't all that practical, but I feel like something the size of the 90mm framelines wouldn't be the end of the world. Personally, I don't think I'd find the persistent double image in parts of the frame all that distracting. Despite the popular conception that looking through an RF viewfinder is simple and clean, there's quite a bit of stuff you have to ignore when you are trying to simply view a scene and compose, especially with modern RFs.

 

[maclaine]

There have been uncoupled/accessory full-frame rangefinders early on in history, but they were no success - the early, working ones were tiny, barely bigger than the centre spot on a Leica M. Given the increasing risk of severe misreadings outside the centre spot in a larger field of vision whenever the eye is off-angle, it did not make any sense to show a distracting and potentially wrong dual image all over the frame once rangefinders got bigger and provided better eye relief.

Full-frame split-image works better and made it into some coupled rangefinders, but even that did not make it past the WWII break in camera design.

Sevo

Great info. Thanks for the history lesson, Sevo!