I was researching whether or not a medium yellow filter is needed when shooting modern B&W film. And then I found this article: Using Colour Filters for Black & White photography It says you need to overexpose 1 stop if using an orange filter, and 1 to TWO stops if using a red filter because your camera meter is fooled by the filters! I never heard of such a thing. The only thing I can figure is that they meant to say a hand held meter not reading through the filter will give the wrong exposure. Comments...?