eyeglasses with permanent framelines in the lens

[tumblinglight]

50-85mm fov frameline ezeglasses by tumblinglight, on Flickr

I am wondering, since i want to internalise the 50, 85mm FOV, is it posible with minimal investment to copy the Voigtlander kontur viewfinder and develop its principle (view with the primary eye the picture while with the other - you must have 2 working - through a black lens with only the framelines 50 or/and 85mm transparent) for eyeglasses?

That sounds tempting to me, but i don't know an optician perspective. Will it be easily done? Not for wide fov, just 50, 85.
Any geeks here?

 

[Scrambler]

If you have a donor pair of glasses, why not give it a go and tell us?

I would cut inner and outer black masks (rather than attempt to cut a traditional frameline mask) and glue (paste) onto the lens of the glasses. Cut the outer mask first, and a smaller hole than you expect to use, and then keep trimming until it gets to the right size.

If you want two framelines, that would be three concentric masks.

 

[Rob-F]

I'm afraid the framelines will be badly out of focus at that distance. Viewfinders use a more complex optical system, to get the framelines in focus, than eyeglasses have. A better idea would be to cut an opening in a piece of cardboard to give the desired FOV when held at some specific distance. Or how about one of those viewers, like movie directors use? Or just keep an accessory finder on you, and take it out when you want to practice?

 

[kossi008]

I use the following trick for the 50 mm FOV:
Spread the fingers on both of your hands as far as they'll go, then hold the hands out at arm's length with the thumbtips touching. Works amazingly well.
Oh, and use just hand for 100 mm...