The only official of doing this is OEM providing the code which means 3rd parties do 'cheat': they either use (yet) unused codes (which may create future problems) or clone codes from supposedly equivalent OEM lenses (like if Sigma 18-55/2.8 used DA16-50/2.8 code).
In the end, the only way to be sure of anything is to use OEM lenses and no theird party lenses (hum...). Even if a code is used only by a third party, a software provider (say, Adobe) may or may not want to take it into account. In the end, some lenses are recognized perfectly, some are recognized as something they are not (at all) and some are never recognized at all. OEM lenses always end up being recognized. Anyone who wants to fiddle with codes can: * open an EXIF from e.g. DA60-250 with an EXIF viewer, * note the corresponding code, * find the correspondance table in the target software, * edit the table to reflect the correspondance betwwen code and lens name. AFAIK, the focal length is always OK, just the lens name which is tricky. You probably do not want your Sigma lens to identify itself as a Pentax lens, specialy if you're comparing the two lenses deciding which one you need to keep :o This is all really a simple stupid thing but it may have consequences. IMO anyone interested in this should always check how a third party lens idetifies itself as to minimize confusion. Hope it helps. -- Thibault Massart aka Thibouille ---------------------- Photo: K10D,Z1,SuperA,KX,MX, P30t and KR-10x ;) ... Thinkpad: X23+UB,X60+UB Programing: D7 user (trying out D2007) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
