On 21 Jun 2005 at 15:19, Joaquim Carvalho wrote: > Is it purple fringing? If so it may be the ultraviolet light, can you > try with an UV filter? > http://dpfwiw.com/filters.htm#fringing
I suspect that paragraph contains more conjecture than truth. Most modern lenses pass very little UV as it is. This line: "there may also be a contribution from CCD blooming due to UV contamination of sensels already near saturation" suggests that the tri-colour pixels exhibit some special response to UV, this is not the case the sensor photo-sites simply accumulate photons. If any UV did reach the sensor surface I'm sure it would more readily pass some visible light filters than others but I'll be very surprised if the post processed colour cast of the UV exposure ended up to be purple. Bloom also often consists of heavy green outlines and as you should know green is in the middle of the visible light spectra. > On my tests the SMC M 50mm 1.7 and the SMC A 50mm 1.4 did as well as the > F versions. I've generally found the M versions of the 50mm lenses to lack the contrast of the A versions. 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
