Developing Methods to Study Camera Ergonomics

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 1A and Photo 1B.  We begin with each camera being held in a comfortable fashion for image capture.  Camera A has a direct manual zoom operation requiring two fingers of the left hand to be on the lens. The zoom action of Camera B is operated by a lever around the shutter button. therefore the left hand can continuously hold the body of Camera B.  Note, by the way, the right hand position on Camera B is more natural, that on Camera A more cramped, due to the different handle and thumb rest design.

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 3    Step 2.  For Camera A only, the left hand returns to holding the zoom ring on the lens.  Camera B does not require 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.