Eric,

Thanks for the info, I should have been able to think this through had it occurred to me to look at a film response curve in addition to the filter curve. I recall reading somewhere that one of the modern films (TMX or TMY?) had less blue sensitivity than Tri-X; I suppose if one were making a modern version of this meter it would be necessary to at least consider whether this difference is significant enough to affect the filtering.

Donald,

Now that you mention it, I remember Fred's leaf-IR example. I sold my newsletters some years ago, or I'd have looked it up. In light of Eric's answer, I couldn't in good conscience ask you or anyone else to search for this info.