LCD shutter?

[MattCarey]

Hello,

I see on the web these 3D glasses based on LCD shutters. I keep thinking that these LCD shutters might make a good substitute for a packard shutter--i.e. a way to add a shutter to a lensboard for a barrel lens.

Any thoughts on why this would be a stupid idea?

A couple come to mind quickly
1) the LCD might act as a polarizer
2) the LCD might not block 100% of the light in the dark state
3) I can't find the LCDs not in the glasses. In the glasses, they are too small.

 

[bobfowler]

My father and I (he was a research engineer at GTE labs at the time) played around with LCD's as a shutter back in the mid 1970's when we experimented with making an electronic enlarger (long story, it sort of worked, but not very well). The LCD's we had available to us back then didn't come close enough to being opaque enough for film, though it did work well enough for B&W enlarging paper. Color paper (the purpose of the project) didn't like the LCD at all, but we never got to the color phase.

We were using a 5" high resolution CRT as an imaging device with the whole she-bang mounted in an old 2x3 Federal enlarger. Image capture was using a 2/3" video tube, a Pentax bellows and slide copier, and a 50mm f/1.4 SMC Takumar. The lens was the best part of the project...

We were just thinking too far ahead of the available technology...

 

[Donald Qualls]

In addition to issues with opacity, there are issues with transparency. Because an LCD absolutely requires polarizing material before and behind the actual liquid crystal layer, it can transmit no more than 50% of the light that falls on it (in practice, a bit less than that) -- and acts as a polarizing filter, since transmission LCDs use the same filter orientation before and behind. Loss of (in practice) about 1 1/2 stops, and a willy-nilly polarizer (which also prevents use of a proper rotating polarizer) make an LCD shutter a pretty specialized animal...