First, I want to say I read related threads but it is still not clear for me. I have a B+W 090(25)red filter and I always use it, almost never take it off.I mostly use spot metering and meter directly with my Eos Elan7e camera. I guess I always get the right exposure. A professional photographer which I really trust told me that the results of TTL metering with the filter are always wrong at least 1 stop,I need to meter without the filter and use the filter factor. I came home and made metering tests with filter and without filter+filter factor, both results were same.I have my own results but his words, I am confused. Thanks,
