I wouldn't increase exposure just because it may have "lost IR sensitivity" due to storage-Keep in mind that this is slide film with IR *sensitivity*, causing a color shift. You expose based on the rating of the film. you may just lose some of the color shift craziness due to lack of sensitivity. Being long expired though, *that* may require a bit more exposure. Definetley bracket this one, as you have 2 things going against you in an already tricky film.
Originally Posted by NeoThermic
Personally, I rate it at 200 for "bright" days with some light haze and 320 for "blazing bright days with lots of reflection (sand, white, etc) and no cloud" at sea level, around the 53 parallel N, middle of summer. This was based on what I found in Begleiter's book, who is in the USA so it probably depends more on equipment than geographical location. I use the Cokin #'s 1 and 2, depending on the look or effect I'm after. I posted samples in another EIR thread here somewhere. I approach FF for HIE and EIR the same as I do for non IR films- meter through the filter with your ISO set. I don't add a Hutching's Factor for HIE though and I do for non-IR, but that's totally OT. It works fine for the EIR as long as you meter carefully (I blew a roll by being lazy and going "sunny 16", regardless of the sun's direction over the course of an afternoon and I underexposed everything by about a stop. Mind you, this was at high elevation in Utah and weird things happen there ). The #1 is about 0-1/2 stop and the #2 is about 2/3 - 1 stop added exposure in my hands.