Howard, As a retired physicist I perhaps understand the descriptions more readily. Here are 3 sites, from Google (out of the first 4 I found). http://www.elec.gla.ac.uk/groups/opto/Kerr.html http://www.thefreedictionary.com/Kerr%20cell http://www.photonics.com/dictionary/lookup/XQ/ASP/url.lookup/entrynum.2764/letter.k/pu./QX/lookup.htm For a reference to the use of the Kerr Cell as a shutter, try the Focal Library book, Applied Photography, by C R Arnold, P J Rolls J C Stewart, I have the First Edition, 1971. If people like I can extract the page to an e-mail. Jim Thyer ----- Original Message ----- From: "Howard" <howard.leigh@xxxxxxxxxxxx> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@xxxxxxxxxxxxxxxxxxxxxx> Sent: Friday, November 19, 2004 9:29 AM Subject: Quiz re Shutters > "Basic Materials and Processes of Photography by Stroebel, Compton, > Current and Zakia" > > This book is expensive... > > However, revealing my true ignorance (I assume that only I don't know of > them since no-one else queried them!) I can't find anywhere a simple > reference to Kerr Cells / optical effect within the normal practice of > photography. In fact I couldn't, with a search in Google, find a > readable indication of what a Kerr Cell is... > > Any URLs easy on the eye and intellect please? > > Howard >
