Archived posting to the Leica Users Group, 2003/07/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Robert, Crazing usually refers to the breakdown or failure of the anti- reflective layer coating. It can look like a series of hairline cracks on the surface of a lens. It is acutally the layer on top of the lens put there to enhance light transmission. This breakdown can occur over time and can be accelerated with exposure to some cleaning agents, extreme temperature shifts and general physical abuse. The newer antireflective coatings for camera lenses as well as spectacle lenses can be 9 layers or more including a few SiO2 (silica dioxide) layers - otherwise known as qaurtz to enhance scratch resistance. If the crazing covers enough of the surface area of the front element, it will lower contrast of the image. I have heard of technicians that can clean the surface and re-coat. I have nevere seen such a lens after treatment but it is technically possibel to do so if the lens suface is intact. Perhaps someone on the list knows the camera technician who polishes and re-coats lens elements. Richard Clompus, OD Roanoke, VA > Is crazing repairable? > Robert VanLane - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html