CAMERA ERGONOMICS
Part 2, How I developed a method
for systematic evaluation of camera ergonomics
Author AndrewS
In the early days of my quest, I read many camera reviews. I
was surprised to find a paucity of systematic description of ergonomic
issues. By way of contrast I found
extensive presentations of a multitude of factors affecting image quality.
There was a well developed language and taxonomy (classification by principles)
of image quality, but nothing remotely comparable for ergonomics.
This was disappointing. My long experience of using cameras
had led me to realise that once a camera's image quality was "good
enough" for my purposes, it mattered not that some other model might have
slightly better image quality. The things which determined if I could live with
and continue to enjoy using a camera were it's handling, viewing and operating
qualities. In a word, ergonomics.
Likes and preferences As a method for evaluating these qualities I considered
lending some cameras to people and seeking their feedback. But on reflection I
realised this approach had serious deficiencies. The feedback received would
consist largely of the participant's "wants",
"likes" and "preferences". There are three problems with these attributes.
First they are transient. The things which a person likes
today will be different next week or next year as a consequence of that
person's experience.
Second they are
idiosyncratic. They are meaningful to that individual for the person's own
reasons, whatever they may be, and cannot be assumed to generalise to anybody
else.
Third, they are often unformulated. By this I mean that when a person is asked to
say what they "want" in a house, car, partner, camera etcetera, they
will often say one thing but after using, living in or with that choice, come
to realise they really would rather something or someone else.
I wanted to develop a robust, systematic method of
describing and evaluating camera ergonomics based on observations of fact which
could be made by anybody having access to the camera, independent of wants, likes or preferences.
Functional anatomy of
the human hand One of the basic
principles of ergonomics is that the tool should fit the user, not the other
way around. As the "tool" in
this case is a hand held device the logical place to start is a study of the
capabilities of the hand. I have a medical
background which made the task easier. I examined and photographed my own hands,
which are of average adult male size and shape, in a variety of positions. I investigated which
positions are natural and relaxed, which are cramped and feel unnatural. I
explored the range and direction of movement of each of the fingers, exploring
which operate best as "grippers" and which as
"controllers".
Handle styles and mockups Many cameras have some kind of handle on the
right side intended to improve the user's grip on the device. Looking
at many cameras I realised that I could classify them broadly into four types,
with intermediates not uncommon. These are No Handle, Mini Handle, Projecting Handle
and Parallel Handle. Big cameras often use the projecting handle. I noticed
that many camera makers use the same projecting handle style on their small
cameras, with unsatisfactory results. Hands do not shrink to fit smaller
cameras, which must be shaped differently from their larger siblings if the
result is to work properly.
I made several handle mockups from scrap wood and used these
to explore the relationship between the handle and the hand without the
distraction of an actual camera. This process led me to some very clear
insights about handle design in cameras of different sizes.
Full camera body
mockups The next step was to make
some full camera body mockups, also from scrap wood I had lying about in the
garage. With each project I used an existing lens mount and flangeback distance
as the starting point, assumed a design with inbuilt eye level viewfinder and
75mm monitor, then built around this a shape which best fit my hand. In the
process I gave considerable thought to the way smaller and larger hands would
interact with the grip. I whittled and played around a lot with pieces of wood,
altering the shape many times until it felt comfortable, secure and stable in
my hand.
This exercise provided a great deal of insight into the way
all the different parts of a camera relate to each other and to the user's hands. I discovered that large and small cameras
can be designed for satisfying ergonomic
performance but there is a size below
which good handling is difficult to achieve.
Camera use task
analysis
Cameras come in a great variety of shapes and sizes. They
have a range of different specifications and capabilities. But in every case, the user has to carry out
a series of tasks in order to operate the device. The principal tasks are Holding, Viewing and
Operating.
The human assets which do the work are
* Hands and Fingers which must hold and operate the machine simultaneously
* Eyes to view the subject and camera data
* Brains with cognitive ability to form and carry out the
photographic intention
I realised that a well designed camera would fit the user's
hands, eyes and brain to streamline the performance of each of the main tasks
of camera work. It seemed to me that a
practiced user would have to pay very little attention to the process of using
a well designed camera. This would allow the user to direct most of his or her
attention to the subject.
Task analysis by
timeline
I found that my analysis of camera operation became much
more coherent when I defined four phases. These are Setup, Prepare, Capture and Review.
Each phase has a different set
of tasks and time constraints.
Task analysis by
hierarchy
The two critical operations which must take place
immediately before image capture are Exposure and Focussing. Within these there
is a hierarchy of parameters which must be controlled. To make sense of this I
have divided them into Primary and Secondary Capture Controls. Primary controls
require a more direct and immediate adjustment procedure than secondary
controls.
Analysis by user
group From an operational
perspective there are two types of camera users. Snapshooters have better things to
do with life than bother about apertures, shutter speeds, etc. Controllers want direct control over
camera functions in the quest for better results. The most difficult camera to
design is one which meets the requirements of both groups. On thoughtful
reflection about this I realised that the issue is ergonomic in nature. It is
separate from other considerations such as whether the photographer is a
beginner or expert. There are plenty of
experienced Snapshooters out there and more than a few inexperienced Controllers.
Time and Motion
studies In 1948 Frank and Lillian
Gilbreth wrote a book, "Cheaper by the Dozen" which popularised the
concept of time and motion study. I used
these ideas to analyse how cameras operate. I dissected each action required to
make something happen on a camera. I counted any required changes to the grip
with either hand. I counted the number of button presses, screen pushes or
whatever a particular camera required. I noted whether the hands or fingers
maintained a relaxed, neutral posture or whether they were required to stretch
into uncomfortable positions. I noted whether controls could be operated while
continuously viewing the subject. I noted whether the operation of controls was
integrated with the capture process or a distraction from it.
I noted huge differences in the Human Machine Interface
(HMI) between cameras of similar size
and general appearance. It became apparent that the controls of a camera could
in many cases have been dramatically improved by a relatively minor
repositioning and retasking of control interfaces (buttons, dials etc). In
other cases nothing short of total redesign from the chassis up would improve
the situation.
Using a camera:
Improved understanding by analogy with other activities Increasingly, the corporations which make
cameras have a very big presence in the
market for touch screen gadgets. Many of these can take photos. This could
easily lead one to the idea that smart phones, touch pad devices and cameras
are analagous. My analysis leads me to a different understanding entirely. The
way a camera operates is more like a motor car than a touch screen device. The
driver of a motor car looks through the windscreen at the roadway and operates
the vehicle's controls entirely by touch without taking his or her eyes off the
road and without having to think much about the process of operating those
controls. The user of a touch screen device looks at the device, not through
it, and directs his or her attention to the symbols on the screen. Ideally a
photographer looks through the viewfinder at the subject and operates the
controls by feel without having to distract his or her attention away from the
subject by looking at those controls. If cars were designed to operate like
touch screen devices everybody on or near the roadway would die. Presumably nobody will die if cameras operate
this way but there will be many lost photo opportunities and the user
experience will be less enjoyable than it could be.
The Style factor Style has always been a factor in camera design. I gained new
appreciation for the importance of style when I made full body mockups. Some of these had excellent handling
qualities but looked strange to my eyes. When working with actual cameras I
realised that many of these were shaped to conform to a particular style,
sometimes to the detriment of handling qualities.
Size Matters The advent of mirrorless interchangeable
lens technology was like the starting gun for a race between manufacturers to produce the smallest camera, as if small size
had some intrinsic virtue. After using several of these cameras over a two year
period, I came to realise that some were so small that their holding, viewing and
operating functions had become impaired. In their quest for the tiny
championship, cameras discarded the inbuilt eye level viewfinder, inbuilt
flash, hotshoe and shooting Mode Dial. Many had a reduced set of tiny, hard to
feel controls, forcing the user to either stay in snapshot mode or fiddle with
menus and workarounds to access primary exposure and focussing parameters. this
experience helped me to gain a sharpened understanding of the HMI.
Photographs This little series of photos illustrates a
time and motion analysis of a single task, that being to shift the active AF
area from the center to a peripheral location in the frame.
 |
| Photo 1A Camera A Start |
 |
| Photo 1B Camera B Start |
 |
| Photo 2A Camera A Step 1 |
 |
| Photo 2B Camera B Step 1 |
Photo 2A, Photo
2B Step 1. For Camera A the left
hand must be lifted completely off the lens and brought back to press the AF
button on the left side of the monitor. The button cannot be located reliably
by touch, so the operator has to look away from the monitor to see the
button. For Camera B the right thumb has
to drop down slightly to find and press the required button. This needs only a
small movement of the thumb which can easily find the button by feel so the
operator can continue to view the subject. The left hand stays in place now and
throughout the task.
 |
| Photo 3 Camera A Step 2 |
 |
| Photo 4A Camera A Step 3 |
 |
| Photo 4B camera B Step 3 |
Photo 4A, Photo
4B Step 3. On both cameras the
right thumb now moves down to the 4 way controller and directs the AF area to
the required location. The action is essentially the same in each case. However
you can see in the photos that with
Camera A, the right hand has to drop
away from the right side of the camera while with Camera B, the right index
finger can stay on or very close to the shutter button and close to the right
side of the camera. This and the continuing hold with the left hand, allow the user of Camera B to maintain a more
secure grip on the camera during the task.
Finish. To
complete the task both cameras return to capture readiness with a half press on
the shutter button.
Summary. Shifting
active AF area on Camera B requires fewer actions, each action is less complex,
and the camera is held more securely throughout the task. In consequence, I find that I shift the AF
area on Camera B frequently but do so rarely on Camera A.
Comment The ability to quickly move the active AF area
is particularly handy in several photographic situations. For instance if one's
subject is a person one wants the face to be in precise focus. This will rarely
be in the centre of the frame. One
solution is to focus/ lock with the centre area then recompose. But with most cameras this will
lock exposure also, resulting in the risk of incorrect exposure.
Although one of these cameras is better than the other, neither provides a very efficient method of
moving AF area. A correctly positioned and configured JOG lever would do the job much more quickly.
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