|
 |
|
|
| |
 |
HOW–TO |
 |
Perspective & The Nature Photographer
How To: Add perspective control to your photographic tool kit for straighter trees, upright buildings and towering cliffs
Text And Photography By Rob Sheppard And Gary Alan Nelson |
|
| |
| |
Do you ever wonder why
some of the classic photos of stands of trees or tall cliffs look
so majestic compared to the results most people get with their cameras?
Ansel Adams, Eliot Porter and other masters of the landscape often
brought a different perspective to their images, and this perspective
isn’t about their creative eye.
Sometimes new photographers confuse the technology with the photographs
when looking at classic work. Adams, Porter, Hyde, Weston—all
of them photographed with large-format view cameras, so the thought
is that this grand scene of majestic subjects comes from using a large-format
camera, and 35mm (or digital cameras) can never match it.
|
|
| |
|
|
| |
|
|
| |
That’s not exactly true. A view
camera can offer unique features and a stunning transparency or negative.
However, when we look at classic images that make trees look like
Greek columns or grand landmarks with a stately air to them, we’re
often responding to the photographer’s control of perspective
in the image. The view camera makes this quite possible to do, but
if you understand the principles involved, you can gain control over
perspective in your photos, too, regardless of your equipment.
We’ll look at perspective control from four points of view:
view camera controls, specialized lenses for 35mm, wide-angle shooting
and computer corrections. First, let’s look at perspective in
the landscape.
Perspective is a fact of life in the world. Close objects are larger
than big objects farther away, which is one way we judge distance.
Parallel lines are wide near you and seem to converge toward a single
point in the distance; a classic example is railroad tracks.
This happens with trees, too. Trees are vertical, often parallel lines.
When you stand even with the base and look up, the closer parts of
a tree are largest. They get smaller with distance and the “parallel
lines” no longer look parallel. They converge, making the tree
lean inward and backward.
This can be a dramatic effect if you get in close and use a very wide-angle
lens. However, when shooting with more normal focal lengths, the trees
just lean in a little as long as you’re pointing the camera
up; this lessens the feeling of height and majesty. Similar effects
happen for nearly any subject that has some height, even to the effect
of cliffs or ruins looking like they’re leaning over backward.
The only way to correct this when shooting is to keep your camera
back (the “film plane”) parallel to your subject. This
way, there’s no perspective change to the subject from bottom
to top.
However, this isn’t always possible. Often, you have to shoot
from below trees or a cliff, meaning your camera has to point upward.
So the lines will converge, losing the majestic feeling you might
have been after.
Perspective And The Standard Camera
There are three ways of correcting perspective with the average camera:
shooting straight on to the subject, using perspective-control lenses
and shooting with a wide-angle lens.
As mentioned above, it isn’t always easy to shoot a subject
straight on. However, if you look around, sometimes you’ll find
that you can get some height so you can point your camera directly
at the subject. You need to be able to set up the camera with an absolutely
vertical back, tilted neither up nor down. This will ensure the back
is parallel to the scene. Any camera will work for this. It can be
worth a try.
Using a telephoto lens on the scene can make it easier to keep the
perspective straight. To fill the image with the subject when you
use a wide-angle lens, you often have to get so close to the subject
that you’re forced to point the camera upward. With a telephoto
focal length, you have to back up, which flattens the angle at which
you have to shoot, making the camera back closer to parallel to the
subject. Naturally, not all subjects can be photographed this way,
since you can’t always back up enough to include the whole scene.
Perspective-control lenses make this a little more straightforward.
Canon and Nikon make them for their cameras in a range of sizes from
wide-angle to telephoto (the wide-angle lenses are probably more useful
for the nature photographer).
Regardless of the focal length, the important thing is that the lens
shifts up and down, as well as side to side. This allows you to set
up your camera straight on to the scene, even though the subject is
higher than the camera (or lower—these effects also show up
if you point the camera down). If you looked through the camera at
this point, you probably wouldn’t see the whole scene; you’d
want to tilt the camera up.
But you don’t have to! Now, you simply shift the lens itself
upward until you can see your desired composition. Obviously, this
is best done on a tripod. The back of the camera is still parallel
to the subject, so vertical lines stay vertical, and trees and cliffs
look majestic.
You actually can shift the lens in horizontal dimensions, too, for
special purposes. A common benefit of this is when you’re limited
in the space available for shooting a scene. Angling the camera may
give you more perspective than desired, so set the camera parallel
to the scene and shift the lens to one side to gain the composition
needed.
—Rob Sheppard
Perspective And The View Camera
The ability to move parts of the camera separately is a primary determining
factor when selecting the view camera as a tool for landscape photography.
The lens on a view camera moves independently of the back or film
part of the camera body and is capable of controlling perspective.
With these movements, a photographer can correct or manipulate the
appearance of the final image.
The first thing I do in the field after determining a composition
is make sure my camera is level, front to back and side to side. There
are horizontal and vertical lines on the ground glass, but often there
are no parallel lines in the field with which to line them up. Small
bubble levels attached to the tripod head or camera work well. I’ve
tried eyeballing, only to see images flow off the frame when I get
my film back from the processor.
A number of technical movements on the view camera can then be used
to control perspective. In using these movements, don’t let
the physics of “bending” light bog you down. It’s
important to realize that what you see on the ground glass is what
you’re going to get on film (providing it’s properly exposed).
The most important movement for perspective is rise and fall. This
allows you to move the lens up and down (or the back of the camera)
while keeping everything else locked down.
If my composition requires more room at the top of the frame, to include
dramatic skies over of a stand of trees, for example, I’ll use
the rise function on my camera. The rise essentially lifts the lens
up while the camera back stays level. The trees remain parallel to
the sides of the frame. Simply tilting the camera up to include more
sky will produce converging lines, which will lean toward the center
of the frame. Naturally, I reverse these techniques if I need more
space at the bottom of my composition.
Keep in mind that these movements are suggestions to make images appear
parallel and “square.” However, I’m a proponent
of breaking the rules. If you want trees bending toward the center
of the frame, or want to exaggerate perspective by manipulating movements,
go for it. It’s all a part of controlling the perspective the
way you want. Aperture adjustment may be necessary to accommodate
film and subject planes, but you can determine your limitations simply
by looking on the ground glass.
The technique applied to rise and fall also holds true with horizontal
movements, called shifts. A shift moves the lens to the right or left,
allowing more room on either side of the frame while keeping horizontal
lines on the film and subject planes parallel.
The rise, fall and shift movements are effective techniques to keep
your vertical and horizontal lines in perspective. Another useful
and often utilized function of the view camera is the front tilt,
which enables you to get foreground and background items in focus
when a small aperture isn’t enough.
By tilting the front of the camera down, you’re given an extended
range of focus from near to far (the plane of focus is tilted). You
can determine how much depth in sharpness you’ve gained by looking
at the ground glass and refocusing after tilting the lens. It may
take a few adjustments to get the maximum effect, but you can see
it all unfold on the ground glass. You do have to be careful of where
the plane of focus cuts through the image. It’s possible to
have flowers in the foreground and mountains in the back sharp, yet
the tops of nearby trees out of focus.
—Gary Alan Nelson
Perspective Control In The Computer
If your image is already shot (maybe you have old images that need
a tweak of perspective adjustment) or you can’t use any of the
techniques discussed so far, you can make perspective corrections
in the computer. These corrections are easy to do, but not necessarily
easy to do properly. Most image-processing programs offer some sort
of perspective-control function (although Jasc Paint Shop Pro has
one of the most controllable perspective features on the market).
Here are some ways to do it in most imaging software. You’ll
have to check to see how your specific program works.
1 Crop Tool. On a number
of programs, there’s a perspective function associated with
the Crop tool. If this is checked, you can drag your corners in or
out to correct perspective. While you could add a grid or guideline
to the photo to check lines, an easy way of doing this in many programs
is to move in the side crop edge next to the part of the subject that
you want to correct (next to a tree trunk, for example). Now, move
the corner of the crop box in until the line is parallel to the subject.
This gets the angle right. Then move the crop edge out to the correct
crop position and make the crop. The perspective is corrected automatically.
2 Perspective Transform.
In programs with Layers, you typically can transform a layer with
perspective control. Make your photo a layer, then find the Perspective
tool (it could be in the Edit, Image, Layer or other menu). Adjust
the corners of the photo to straighten your subject. A guideline or
grid can be very helpful (check your program’s Help function
to see how to add them; Grid is often under the View menu).
3 Jasc Perspective Correction
Tool. Jasc has added Perspective Correction as a tool in the toolbar.
Simply use your cursor to place a “box” around your subject,
then line up the corners of the box with the points on your subject
that need to be straightened. Hit Enter and the computer does the
magic.
4 Doing It Right. One
problem with any of these tools is that they ignore an issue of perspective.
When you look at something from below, for example, you can see more
of its bottom than its top. So if you straighten the subject, it will
still have some of that proportion, resulting in a squatty object
that really doesn’t represent the subject.
You need to stretch the scene upward (assuming the correction has
been made vertically) to compensate. Use the Transform Scale tool,
or you can resize the photo by making only the vertical dimension
larger (uncheck Constrain Proportions in Adobe products—and
remember to recheck later!). This can be tricky since there are no
precise scales for the adjustment. Either do it visually so it looks
right or compare it to an unadjusted photo to see if the subject has
the right proportions.
—Rob Sheppard
|
MORE HOW–TOS |
|
|
|
|
By Subject
Look here for the techniques you need in order to photograph specific outdoor and nature photography subjects
|
|
|
|
|
|
|
|
Photoshop
Discover how you can best use Adobe Photoshop and other image-processing software to optimize and enhance your nature images
|
|
|
|
More How-Tos
Discover the wide range of nature photography techniques and how-to in this varied selection of articles
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
