V1.02
Thom Hogan’s Complete Guide to the Nikon D300
Page 593
Using Flash
Flash use with a D300 is different than with film
SLRs and early Nikon DSLRs. Like all recent
Nikon DSLRs the D300 uses a form of flash
technology Nikon calls i-TTL.
Obviously, I’d love for all readers of this book to
rush out and purchase my
Nikon Digital Flash
Guide
. If you’d like an extended discussion of i-
TTL modes and how flash works, consider
purchasing it. For most D300 users, though, the
sections that follow are probably all you need for
basic flash use
.
What Happens When Flash is Used
Flash isn’t a magical device that simply fixes every lighting
problem you’re facing. Like any tool, you need to understand
how it works and how to best use it. The big “gotchas” I
encounter most frequently with students are these:
•
Flash only lights one distance correctly
. Light falls off with
the inverse square of the distance. If a flash is providing
the correct light for 8 feet, by 11 feet the light will be one
stop less; at 5.6 feet it will be one stop more. The classic
expectation most people have is that flash should light
both a subject and a background that’s many feet behind
the subject. Won’t happen.
•
Two exposures occur when you use flash
. Both have to be
right. This is an extension of the first thing I presented: if
flash is lighting only a subject at one distance correctly,
something else has to provide the exposure for the
background (ambient) areas. That “something else” is the
same thing it always is: the existing light, and the aperture,
shutter speed, and ISO are the variables you use to control
them. The flash (subject) exposure, meanwhile, is
controlled by flash power, aperture, and ISO. Note that
