My dad, an electrical engineer for IBM, would never let us turn our TV's and computers off. He said the start up and power down mechanism of most instruments would in the long run, be more detrimental for their health than just leaving them on... Then again, I'm old enough to remember vacuum tube TV's....haha Denice Barsness, CRA, COMT, ROUB, CDOS, FOPS Ophthalmic Diagnostic Center CPMC Department of Ophthalmology 2100 Webster Street Suite 212 San Francisco CA 94115 (415) 600-3937 FAX (415) 600-6563 From: optimal-bounce@xxxxxxxxxxxxx [mailto:optimal-bounce@xxxxxxxxxxxxx] On Behalf Of Anton Drew Sent: Tuesday, July 10, 2012 3:18 PM To: optimal@xxxxxxxxxxxxx Subject: [optimal] Re: Power switch on TRC 50ex ALL my fundus cameras over the years have been turned on when I get to work and turned off when I leave. I would have a worry about a unit being turned on and off all through the day, couldn't be good for the innards, not to mention delays if you are asked to quickly do some photography. If they don't like the noise, close the door. My 2ccs worth. Anton Drew Adelaide South Australia On 11/07/2012, at 12:37 AM, Tom Steele wrote: Cousin's, One of the photographers has begun turning off the 50ex after every study to avoid the sound of the camera in their office. I don't think it really matters if you leave the camera on all day or turn it off and on multi times. Perhaps someone has information which would enlighten an old dog photographer like me. Thank You, Tom Steele, CRA Midwest Eye Institute 200 West 103rd Street Indianapolis, Indiana 46290 317.817.1018 tsteele@xxxxxxxxxxxxxx