In article
>Impressed by the longevity of some 45-year old Kodachromes I saw >recently, I have decided to take Kodachrome 64 on an upcoming vacation >trip. I have read that good results can sometimes be had by shooting >K-64 at ISO 80 -- (.....)
My advice would be to do what you say you do not have enough time
to do: try it first. In my experience, K64 is correctly rated at
64 IF using a calibrated and corrected meter (some of my Nikons
require "-1/3" compensation [or the equivalent of ASA 80 without
compensation for correct exposure of K64]). If you have experience
with several other slide films and you like the exposures at the
rated speeds, I would recommend using 64 with K64. IM(NS)HO,
slide films need to have less than 1/4 stop error in exposure to
look "correct" - a consistent 1/3 stop error would not be good.
Underexposure is just that, and results in murky, dark-looking
images (see National Geographic for some examples of these).
K64 tends to have undifferentiated black shadow renderings even
at normal rating - underexposure pushes the problem nearer the
middle tones.
Hope this helps.