On 11 Feb 2006 at 21:19, Gaurav Aggarwal wrote: > Hi, > > I have read in books, websites about linear vs. circular polarizer > filters and how circular > are better than linear for SLRs and auto-focus etc. But what really is > the difference? > What do circular provide that linear don't and can one use linear just > as effectively > to reduce the reflections and make sky bluer? Are linear uncomfortable > to use? Do > linear polarizing filters ever have a rotating mount?
Some systems in late cameras such as metering and focussing have sensors that are located in the finder and hence use light reflected off surfaces that may cause some degree of linear light polarization. As you may know when two linear polarizers are rotated such they their polarizing effects are perpendicular they become dark. This same effect can cause erratic behaviour in some cameras metering and/or AF systems when using linear polarizers. A circular polarizer has the same photographic effect as a linear polarizer because it is in fact a sandwich of a linear polarizer followed by a filter which effectively de-polarizes the light so that it doesn't look polarized to the camera innards. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
