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I'm not looking for a graphic or text LCD display here, just essentially a single, large pixel, capable of going from dark-light-dark in under 1ms. The faster, the better.

The idea is to create a secondary shutter for a still camera, increasing the flash sync speed of the camera. Here's a video of a similar idea, but on a CMOS video camera. Seems like they're using a pane from a pair of 3d shutter glasses, which operate at video speeds (60 or 120 hz, not fast enough.)

Something like the panel in an auto-darkening welding helmet would be along the lines of what I need, providing they can also transition from dark-light at high speeds.

What are these called? What can I search for (LCD panel obviously doesn't help)? Where might I be able to find one? (Aside from hacking apart a welding helmet.)

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  • \$\begingroup\$ Those auto-darkening welding goggles claim to be able to go dark in 1/25000 seconds. How are they able to switch so quickly? \$\endgroup\$
    – Evan Krall
    Commented Dec 11, 2010 at 6:18
  • \$\begingroup\$ Be advised that liquid crystal switching speed can be very slow in low temperatures. A range of faster than the human eye can perceive at room temperature to a second for a black/white change at -15 degC is well possible. \$\endgroup\$
    – ndim
    Commented Jan 5, 2011 at 18:58

2 Answers 2

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What you're looking for sounds like an LCD shutter, specifically a Pi Cell LCD Shutter. The more modern welding helmets use the TN LCD Shutters which have the same slower speeds as 3D shutter glasses. From what I've read the Pi Cell LCD Shutters can have a switching speed of up to 1000Hz.

Liquid Crystal Technologies claim they'll send you a free 1"x1" or 4"x1.5" TN LCD shutter or a 1"x1.5" pi cell shutter. The pi cell shutter will be the faster one. I've never needed an LCD shutter, so I can't verify anything any company claims about theirs, but free is certainly worth a try if you can get them to send you one.

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  • \$\begingroup\$ This looks like it might work. Bonus points for linking a place that might provide a free sample. \$\endgroup\$
    – Evan Krall
    Commented Feb 19, 2011 at 10:57
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This would solve a problem in videography: CMOS rolling shutter effect ("jello effect", wobbly vertical lines when panning), which is due to the sensor being read one line at a time.

Modern cameras with a "global shutter" (where all the sensor is read at once) are very expensive. I guess if is just an easy and cheap, all video cameras would be equipped with that now. But I read that LCD shutter cause a great reduction in light transmitted of 50% or more by polarizing light, and it's very hard to make them totally transparent.

Red seem to have used an LCD shutter on one of their (very expensive) digital cinema cameras. I don't know how they do it, and how bad the side effects are.

Anyway if there is an answer I'd be very interested. I mean LCD shutters are found in cheap 3D glasses - I am interested in an LCD shutter with great optical qualities.

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