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Any time you take a picture, focus is important. Most
of the time, it's a fairly easy thing to do, but it gets
a bit more complicated when your subject is very small,
and you need to get real close to it. In fact, sometimes
the way to focus on a close subject doesn't involve the
focus adjustment much at all.
The common method used to focus on living creatures is usually
different from the way you focus on artificial flies in a vise.
This is especially true with SRL cameras and macro lenses or
extension tubes. We'll discuss this more in a minute, but
first we need to look at something called framing your subject.
I think there are more failures in the framing area of macro
photography than focusing errors. An error in either area
will turn an otherwise great subject into a useless photo.
Most people who take family pictures or photos of other
large subjects understand how important it is to "frame"
their subject in the background to provide the best
environment for a nice picture. In macro photography,
the frame is based on how close you can focus to the subject.
If you want the best detail, you need to frame the subject
as close to the lens as possible to best fill the viewfinder
with the insect or artificial fly. It's easier to get a good
focus from farther away, but you lose the very important details
in the subject if you don't fill at least 1/3 to 1/2 of the
slide or print with an insect, or about 80% of the slide or
print with an artificial fly.
I can't tell you how many times someone has asked me why my
insect photos have so much detail and theirs don't. When I
look at their slides or prints, I see a very small subject
lost in a jungle of background. If the background isn't
helpful in giving the photo some sort of scale to measure
size, or if it doesn't add something, move/zoom closer to
the subject and get rid of as much background as possible.
In macro photography, this is called framing your subject.
How entertaining or educational is this photo of a caddisfly?
If you ask me, the subject is lost in a jungle of background.
When I move or zoom closer to the subject, I'm able to
eliminate a lot of background clutter and focus your
attention on the subject. I see more details, don't you?
Which photo do you like best?
As you can see, framing your shot to draw attention to your
subject is important. It's also important to fill as much
of the frame with your subject as possible to provide the
best details. Once you have your subject framed, you can
work on focus.
In an earlier article I mentioned something called depth of
field (that thin slice of air where the subject is in focus).
If I focus farther away from the subject, I gain depth of
field, but lose most (if not all) of the useful details.
The trick here is to learn to focus on the really important
parts of the subject while keeping the frame full of the
subject and little else. Depending on the equipment you're
using and the amount of light you have to work with, you might
be able to gain by setting your aperture to the smallest
setting (largest number on your f-stop settings), but you're
bound to be out of focus somewhere in the photo. So, what
is it you want observers to see? That's what you emphasize
with your focus adjustment.
You can keep the distance from the subject to the lens even
from front to back (very useful if photographing artificial
flies). Or, you can focus attention to the important or
most interesting parts of the subject (useful when
photographing insects) and let the other parts of the photo
drift out of focus.
In this photo, the whole side of the hopper is in focus.
The insect fills the frame and details are good. Fairly
interesting, especially if this was an artificial fly in
a vise, but is it the best shot I can come up with? Since
it's an insect in the wild, I might do better to focus
attention on a part of the insect that's more interesting.
Here I moved to the front of and below the same hopper.
The tail and far legs of the hopper are out of focus, but
I can see the details of the face and front legs much better.
Which shot is best? You decide for yourself. As you can
see, in this case, allowing a portion of the subject to
drift out of focus draws your attention to the area of the
subject that's in focus. It's a tricky way to draw your
eyes to the part of the hopper I want you to see, and the
lack of focus on the rest of the hopper isn't damaging to
the picture.
Let's take it a step further. I wanted you to see the tiny
specks of pollen on the face of this hopper. The only way
I could do that was to focus on the front of the face and
let the rest of the photo drift out of focus. Was your
eye drawn to the image I wanted you to see? How many of
you didn't know it was a grasshopper, even though most of
the insect is out of focus? Which aspect was most important,
focus or frame?
Photographing artificial flies in a vise is a little bit
different. You can't get away with part of the fly being
out of focus; or, can you? Well, yes you can. If the body
is what you want people to see, you focus on the body and
allow the hackle to be a little fuzzy. You control the
situation by determining what is important to see and what
isn't. Granted, you want people to see as much detail as
possible, but you'll still be forced to focus on a part of
the fly if you want the best details to be visible.
In this photo, most of the body and wing are in focus, but
the antennae are out of focus, I want you to see the body
and wing, so that's what I focused on.
This is another small fly. The body and tail are in focus,
but the hackle isn't. I'm betting you can see the hackle
and wing well enough to know what they are, and I know the
body and tail are detailed enough for further study.
This classic salmon fly (tied by Thomas Duncan, Sr.) is large
enough to allow me to move farther away from the fly and still
frame it to fill the picture. Everything except a very small
portion of the wing and the hackle are in focus. If I had
framed either of the other two flies from this far away, you
wouldn't have been able to see any of the details, even though
the fly would have been in focus from head to tail.
As you can see, focus and frame work together to draw
attention to what you, the photographer, want people to
see. It takes practice to get the eye for framing your
subject, but without a useful framework, the picture
is at best boring, even if it's in focus. Focus and
frame are important functions of photography that must
work together to draw attention to the things you want
people to see.
Like I said earlier, sometimes macro focusing doesn't
involve the focus adjustment much at all. Generally,
if you're focusing on a wild insect, you usually do
better to focus by moving the camera toward or away
from the subject. To do that properly, you move the
lens close to the subject and adjust the focus while
moving the camera to just the right distance to fill
the viewfinder properly. Then, you slowly move the
camera closer to, or further from the subject until
you get the focus you want. Once you've found the
right distance for a certain sized subject, further
focusing is done by moving the camera closer to, or
further away from the subject.
For immobile subjects, like flies in a vise, you frame
the subject like before, then you do the fine focus
adjustment with the focus knob. The main difference
between the two methods involves the idea that you
hand-hold the camera for insect photography and have
the camera mounted on a tripod for fly-in-the-vise
photography.
With a digital camera, you still frame the subject, but
the focus is almost always done automatically. Many cameras
either show you where they are focusing, or allow you to
choose where you want them to focus. Since the focus is
usually automatic, you get to work harder on the proper
framing of your subject. Angle and distance considerations
still apply. You just don't have to do as much work to
get the right focus.
Now, get out there and play with your cameras. The only
way you'll get good at this stuff is to work out the details
for yourself, with your own equipment. We still have a few
other subjects to cover, but this time I'm not going to tell
you what's next. See you then.
~ AC
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