Quote Originally Posted by MattKing View Post
It isn't as stupid as you say.

The filter factors work well with ASA/ISO/EI numbers.

They work well with flash guide numbers.

They work well when you use more than one filter.

They work well with films that have different daylight and tungsten speeds.

They work well with calculations concerning bellows extension.

They fit well within a system.
Thanks, I cheat so much with bellows extension (without the reciprocity timer app I would be completely lost as far as bellows go) so I wouldn't know how to properly use the filter factor for that.

The strange part is, somehow all the times I've "incorrectly" used the yellow and red filters, somehow I still exposed relatively correctly and almost always happy with the image. Hmmm... :-0