Advertisement
30
Part I: Fast Track to Super Snaps
The angle of view that a lens can capture is
determined by its focal length, or in the case of
a zoom lens, the range of focal lengths it offers.
Focal length is measured in millimeters.
According to photography tradition, a focal
length of 50mm is described as a "normal" lens.
Most point-and-shoot cameras feature this
focal length, which is a medium-range lens that
works well for the type of snapshots that users
of those kinds of cameras are likely to shoot.
A lens with a focal length under 35mm is char-
acterized as a wide-angle lens because at that
focal length, the camera has a wide angle of
view, making it good for landscape photogra-
phy. A short focal length also has the effect of
making objects seem smaller and farther away.
At the other end of the spectrum, a lens with
a focal length longer than 80mm is considered
a telephoto lens and is often referred to as a
long lens. With a long lens, the angle of view
narrows and faraway subjects appear closer
and larger, which is ideal for wildlife and sports
photographers.
Note, however, that the focal lengths stated
here and elsewhere in the book are 35mm
equivalent focal lengths. Here's the deal:
Focal length and the crop factor
For reasons that aren't really important, when
you put a standard lens on most digital cam-
eras, including the D3300, the available frame
area is reduced, as if you took a picture on
a camera that uses 35mm film negatives and
cropped it.
This crop factor varies depending on the
camera, which is why the photo industry
adopted the 35mm-equivalent measuring stick
as a standard. With the D3300, the crop factor is
roughly 1.5. In the figure here, the red line indi-
cates the image area that results from the 1.5
crop factor.
When shopping for a lens, it's important to
remember this crop factor to make sure that
you get the focal length designed for the type
of pictures you want to take. Just multiply the
lens focal length by 1.5 to determine the actual
angle of view. Not sure which focal length to
choose? Point your web browser to http://
imaging.nikon.com , click the link for
Nikkor lenses, click the Related Links option,
and then click the link for the Nikkor Lenses
Simulator. Using this interactive tool, you can
see exactly how different focal-length lenses
capture the same scene.
Advertisement
