In article <4pr729$jji@h20-hrze.uni-duisburg.de>, martin@math.uni-duisburg.de says... some, about metering with converters, deleted]

>With TTL metering systems there's no compensation needed. That's
>why all SLR cameras have this metering system. It works with all
>lenses, filters (except linear polarizers in most modern cameras),
>teleconverters and all this stuff, because the metering system sees
>exactly what is exposed to the film.

Umm.., unfortunately TTL meters do a poor job of metering most
colored filters for B & W, and often need considerable compensation
to be accurate with them.
Hope This Helps