Kerr cell shutter

File:Kerr cell.svg

A Kerr cell shutter is a type of photographic shutter used for very fast shutter speeds down to nanosecond level.

The Kerr Cell consists of a transparent container (A) filled with nitrobenzene{{Cite web | url=https://people.rit.edu/andpph/text-high-speed.html |title = High Speed Photography}} (B) with attached electrodes (C and D). A high voltage is passed through the electrodes which causes an electric field perpendicular to the transmitted light beam to be applied.

The cell makes use of the Kerr effect, in which the nitrobenzene becomes birefringent under the influence of the electric field. This allows it to be used as a shutter that can be opened for a very brief amount of time, around 10ns.{{cite book|author=Michael R. Peres|title=The Focal Encyclopedia of Photography|url=https://books.google.com/books?id=g4Wx9yKrDS0C&pg=PA545|date=29 May 2013|publisher=Taylor & Francis|isbn=978-1-136-10613-2|pages=545–}}

Its primary disadvantage was the use of toxic and flammable substances such as nitrobenzene and o-nitrotoluene. These have now largely been replaced by KTN (potassium tantalate niobate) and barium titanate (BaTiO3).