Iso Sensitivity Step Value; Custom Setting B1 (D300S And D) - Nikon D300 User Manual

What is an EV?
EV simply means "Exposure Value", which is an
agreed-upon value of exposure metering. It is spoken of in
full or partial EV steps, like 1/3, 1/2, or 1. It simply means
different combinations of shutter speeds and apertures that
give similar exposures. An EV step corresponds to a
standard logarithmic
commonly referred to as a "stop". So, instead of saying "1
EV", you could substitute "1 stop". EV 0 (zero)
corresponds to an exposure time of 1 second at an aperture
of f/1.0, or 15 seconds at f/4. EV can be positive or
negative. EV -6 equals 60 seconds at f/1.0. EV 10 equals
1/1000s at f/1.0 or 1/60s at f/4. The EV step system was
invented in Germany back in the 1950s. Interesting, huh?

ISO Sensitivity Step Value

Custom setting b1 (D300S and D300)
(User's Manual – D300S page 270; D300 page 275)
ISO sensitivity step value
camera handles its progression of exposure values for ISO. In
other words, the camera's ISO "step" value is set with
Custom setting
following values:
▪ 1/3 step EV (ISO steps 200, 250, 320, 400, etc.)
▪ 1/2 step EV (ISO steps 200, 280, 400, 560, etc.)
▪ 1 step EV (ISO steps 200, 400, 800, 1600, etc.)
"power-of-2"
allows you to change the way the
b1. You can control the steps with the
285
exposure step,