It discusses LensRental’s experience in cleaning and repairing various camera parts and systems. Something that was new to me was the recommendation to flip the IS/VR switch to “off” unless your camera is turned on. http://www.pdnonline.com/gear/10-Interesting-Things-We-Learned-About-Cameras-and-Lenses-from-LensRentals-14979.shtml   Jeff Green