CAMERA ERGONOMICS
D.I.Y. ERGONOMIC EVALUATION
How to rate the ergonomics of your own camera
Author AndrewS
Abbreviations HMI = Human Machine Interface
UIM = User Interface Module (buttons, dials, levers)
1. Know thyself What kind of photographer are you ? From the perspective of HMI (Human Machine Interface) requirements I would identify four levels of camera user.
Level 1, Snapshooter, occasional use.
Level 2, Snapshooter, frequent use.
Level 3, Expert/controller, occasional use.
Level 4, Expert/Controller, frequent use.
The occasional snapshooter will be well served by a very small compact or phone cam. The key requirements are very compact size and easy, fully automatic operation. Some shapshooters take lots of photos but don't want to be bothered by shutter speeds, apertures and the like. The key requirements are simple, fully automatic operation, responsiveness, decent image quality and conveniently compact size.
The expert/controller will want a camera which provides much greater opportunities for user control over the camera's functions, with decent viewing and holding as well. For the occasional user, suboptimal performance and ergonomics may be acceptable as a tradeoff for lower size/cost.
The frequent expert user wants the lot. High image quality, excellent performance, good handling, good viewing qualities and excellent operating characteristics. The frequent user will accept higher cost and size to get improved viewing, handling and operating qualities.
The point of this is that a camera which is acceptable to one user could be intensely frustrating for the next. A camera suitable for user levels 1 and 2 will be of little interest to a level 4 user. However a camera with all the controls to satisfy level 4 operation user could suit level 2 users very well when set to one of it's fully automatic shooting modes and will be very satisfactory for level 3 users in any shooting mode. For the remainder of this presentation I will be referring to cameras suitable for the level 4 use.
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| Photo 5, Natural Hold |
2. Describing ergonomics It is possible to describe, classify and rate the ergonomics of a camera with reference to characteristics which can be observed by anybody who understands what to look for. This exercise can be carried out completely independent of a person's likes and preferences. In order to do this the reviewer needs to become aware of the language and principles of ergonomics. For a full discussion of these matters please read Parts 1-12 of my discourse on camera ergonomics in this blog. At the very least please read Part 11 and the summary "Ergonomics in a Nutshell".
There are three main descriptors of a camera's capability: image quality, performance and ergonomics. The first two have a very well developed technology, language and principles by which these capabilities can be measured and described. But the current state of ergonomic analysis is inadequate, as is the ergonomic capability of many new camera models. Early reviews of new camera releases have much to say about image quality and performance, but appreciation of ergonomics may require long term use, with little reporting of insights thus gained.
3. Complexity and information overload My first "serious" camera was a Pentax Spotmatic. This camera allowed you to adjust shutter speed, aperture, focussed distance and nothing else. You could adjust film speed when loading a new roll of film and that was yer lot. By comparison the modern electronic camera presents it's user with hundreds of adjustable parameters leading to information overload every time a photograph is made. This presents a huge ergonomic challenge to the designers of modern cameras. You will not be surprised to find that some makers respond to this more effectively than others. But you might be surprised and perhaps disappointed to discover that camera makers who have been in the business a very long time are no more successful than recent arrivals on the camera making scene. This means you cannot rely on a brand name to deliver good ergonomics.
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| Photo 1 Top |
4. First acquaintance One of the first things you do with a new camera is look at it. With experience, this can reveal a lot. Is it a DSLR ? With this type of camera you can have eye level view or live view on the monitor but it's either/or, with each view type providing a different user experience and focussing technology. You can't segue seamlessly from one to the other. Sony SLT cameras use a type of SLR technology which does allow the same type of operation in eye level and monitor view. Is the camera a mirrorless type (MILC) designed to look like a mini DSLR with a hump on top ? There is no functional requirement for this shape so I have to assume the makers use it for marketing reasons, perhaps believing buyers will recognise this as the shape of a "proper" camera. If they used the flat top "rangefinder style" shape with the same dimensions and EVF located near the top left corner, Leica style, they could achieve a dramatic ergonomic improvement, with more natural viewing using the right or left eye, lens axis shifted to the left (as viewed by the user), a taller and more anatomically shaped handle, much larger rear control panel and much more user friendly interface modules (buttons, dials, levers etc). Are there "Set and See" dials and/or levers on the top plate ? If well designed, these can be extremely handy for adjustments required in the Prepare Phase of use. Are there buttons on the left side of the body ? These can be useful for Prepare Phase adjustments but are incompatible with smooth operation in the Capture Phase.
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| Photo 2 Rear |
4. Setup Phase Before taking photos with a new camera it needs to be set up to suit your individual requirements. There can be a multitude of parameters requiring attention with some cameras having more options than others. Items typically include time and date, language, file and folder settings, display settings, color space, RAW capture, sounds, user interface module (buttons, dials, levers) tasking, aspect ratio, sensor cleaning, monitor and EVF display settings, AF priority, MF assist, focus peaking, analoge distance and depth of field display, EV steps, AEB settings, noise reduction, AF assist lamp, video modes and options, ......etcetera......etcetera.
Does you camera have an instruction manual ? Is it useful ? Does your camera have a menu system which is clear, logical, and easily accessible ? Does the camera have user interface modules which allow easy scrolling and selection of items ? Is there quick access to a user configurable "My menu" for frequently used items ? Are menu items grouped in a way which makes sense to the user ? Some cameras have a convoluted menu system in which a change to one item in one folder of the menu system can force unexpected and sometimes inexplicable changes to other items in different folders.
Are most UIM's user configurable from the full list of camera functions ? Configurability is extremely important in an electronic camera with hundreds of adjustable parameters and potentially thousands of combinations. Be very wary of cameras with manufacturer set single functions on UIM's.
Are the UIM's for Setup Phase located in a low priority area of the camera, where they should be ? Or has the maker put the Menu button in a high priority area which would have been better allocated to a Capture Phase control ? See "Locations" on this blog for more about camera real estate.
5. Prepare Phase Now you want to start making photos. The Prepare Phase of use refers to the minutes just prior to image capture. You need to adjust camera settings for the current assignment, be it landscape, potrait, sport/action, flash indoors or whatever.
Cameras and users vary of course but typical parameters requiring adjustment at this stage include setting P,A,S or M shooting mode, drive mode, flash mode, OIS, video mode and dynamic range control. Also in this group are tertiary exposure parameters including metering mode and white balance. Then we have tertiary focussing parameters including focus type (phase detect/contrast detect) AF mode (single/continuous/tracking/predictive) AF area/type (selection/multi/face detect) AF/MF. There may also be lens based focus controls including Stabiliser ON/OFF, stabiliser mode, AF/MF and focus distance limiter.
For optimum ergonomic operation the user should be able to make all adjustments in this phase without having to enter a menu. "Set and See" dials/levers are very useful for this stage as settings can be seen at a glance and adjustments made quickly. Other UIM's, such as buttons, for this phase need to be located in a medium priority zone on the camera. There needs to be a quick, effective means of scrolling around then selecting options in this phase.
Some cameras use a "Quick Menu" for access to Prepare Phase adjustments. This can work decently well provided that the access module (usually a button) is located in a high/medium priority zone, contents of the Q Menu are fully user selectable and scrolling/selecting options is fast and efficient. A well located and designed JOG lever can be faster than the ubiquitous 4 way controller for this purpose. It is desirable to give users the option to "set" selections either by pressing a specified button or half pressing the shutter button. Some cameras only offer manufacturer preset options in the Q Menu. From an ergonomic perspective, this can be extremely irritating as the review screen will usually be cluttered with items you personally do not want, while other items you do want on the Q Menu are not to be found.
6. Capture Phase Now we come to the sharp end of ergonomics. A photographer who wants to take control of the process of image capture has a great deal to do in a very short time. He or she must note and consider numerous data inputs then make a series of decisions leading to immediate actions at the point of sensor exposure. The process requires an operator with knowlege and practice. It also requires a camera designed by photographers to ensure it is optimised for ergonomics. There are three main tasks in this phase, holding, viewing and operating. At the risk of labouring the obvious, I would point out that all three tasks must be performed simultaneously. Unfortunately, too many modern cameras make the job far more difficult than it needs to be.
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| Photo 3 Set and See Dials |
Holding Please refer to Parts 4, Functional Anatomy, 6, Hands and Fingers and 7, Handles and Holds, for detailed discussion. Please find the time to read these chapters of the story of ergonomics as they contain much information. A fully sculpted, anatomical handle and thumb rest allow the user to obtain a secure and stable hold on the device. This is the functional platform which forms the base for good operation. Good handle and thumbrest design is not something which can usefully be stuck, like an appendage, onto some pre-existing camera shape. For optimum ergonomic function the handle and thumb-rest need to be an integral part of the total design from the ground up. Please refer to Parts 10, Operating Systems and 12, Mockups, for more discussion on these issues.
Questions to ask when evaluating your camera's holding include: Does it have a comfortable, anatomically sculpted handle and well shaped and positioned thumb rest ? Does the camera encourage the user to hold it with the natural "half closed' position of the right hand ? Can you operate the main Capture Phase controls without disrupting grip with either hand ?
Viewing Please refer to Part 9, Viewing systems for detailed discussion. The total spectrum of viewing systems on modern cameras is very complex. As a user you need to view two completely different cognitive categories of information. The first is preview/review of the image captured. The second is camera status data.
Questions to ask include: Does my camera have a monitor screen and eye level viewfinder ? Each has it's uses, not always interchangeably. Is there a seamless segue from one to the other ? Can the monitor be tilted/swung/swivelled ? Is camera status information displayed beneath (easier to see) or superimposed on (harder to see) the image preview/review ? What is the quality of the preview image ? Can the display be user configured ? What range of options is available ? Is the effect of adjustments made with UIM's immediately evident on the monitor and eye level viewfinder ? Does this include both the image preview appearance and data readouts ? Is the image preview accurate as to boundary and appearance? Are there "Set and See" dials on the camera body giving instant access to camera status information ?
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| Photo 4 Natural Hold 1 |
Operating Please refer to Part 10, Operating Systems and Part 12 Mockups, for detailed discussion. The main operating tasks in the Capture Phase involve evaluating then adjusting as required, primary and secondary exposure and focussing parameters. All this needs to take place in a few seconds so the ergonomic design requirements are very stringent.
Primary exposure parameters are Time Value (shutter speed), Aperture Value (f stop) and Speed Value (ISO). Primary focussing parameters are Start/lock autofocus or Operate manual focus. Some cameras allow both simultaneously.
Secondary exposure parameters are exposure compensation and program shift (in P Mode). Secondary focussing parameters are autofocus area position and autofocus area size.
My research leads me to the conclusion that for a conventionally shaped hand held camera driven like a sports car by a practiced operator an excellent way to achieve smooth ergonomic flow for the above tasks is as follows:
Left hand holds and supports the lens, operates zoom and operates manual focus if selected.
Right index finger operates four UIM's, controlling primary and secondary exposure parameters: shutter button, main control dial, ISO and exposure compensation, without having to move a muscle of any other finger of either hand.
Right thumb operates two UIM's, controlling primary and secondary focussing parameters. These are Autofocus Start/lock (using a back button AF start module) or AF lock and Active AF area position/size (using a JOG lever).
Obviously there is no general agreement among camera makers or users that the schema detailed above is the best or even most desirable ergonomic solution to the camera control problem. But I want you to think about this: If you test drive a motor car which you have never seen before, you will be able to get in and drive it right away. No need to consult the instructions, cars have a steering wheel, pedals and hand controls which all work essentially the same way. Camera designs are by comparison floundering about all over the place, with no general agreement on anything. If cars were designed like cameras every one of them would crash in about three seconds.
However back to your camera, dear reader. The questions you might want to ask include: Can you easily see status indicators of primary and secondary exposure and focussing parameters in the monitor and/or viewfinder ? Can you, while viewing the subject continuously in the viewfinder and without shifting grip with either hand, easily and smoothly adjust those parameters by feel without having to stop the process to look at one of the UIM's ? Are the UIM's for Capture Phase adjustments located in High value areas of the camera ? Are UIM's for Setup, Prepare or Review Phase located in high value positions, thus displacing Capture Phase controls to less desirable positions ?
More generally does the process of making adjustments to exposure and focussing controls become second nature with practice allowing you to concentrate your attention on the subject ? Or are there irritating roadblocks in your way every time you want to take a photo ?
Specific ergonomic issues
* On /Off switch. Over the years I have used cameras with O/I switches, levers and buttons all over the place. I have found that one of the best is a lever around the shutter button. This allows the user to see or even better to feel, while carrying the camera, whether it is on or off and to change the setting by feel, using only the right hand, without having to look at the camera.
* The eye level viewfinder Most cameras do not have one of these. However there are several circumstances where an eye level viewfinder is essential or at least highly desirable. In bright sunny conditions I have never yet encountered a monitor which allowed me to clearly see the image preview and all the camera data on or below the screen image. Telephoto lenses and low light levels require the camera to be held steady, a task greatly helped by pressing the camera against the bones of one's head. Eye level viewing helps the user separate from the distraction of his or her surroundings and concentrate on the subject.
* Touch screen controls These are very popular at the moment (May 2012). I own and use several cameras with this feature, which I have subjected to careful ergonomic analysis. They are inaccessible and therefore useless with eye level viewing. With monitor viewing they are accessible but involve getting fingers over the subject preview and disrupt holding. Furthermore it is cognitively disorienting to use one set of UIM's when eye level viewing but an entirely different UIM set when monitor viewing. Tripod mounted is the only condition in which touch screen controls can be ergonomically harmonious with the process of image making.
* Lens based UIM's Ring type UIM's work well on lenses for Capture Phase tasks. They are easy to locate by feel in landscape or portrait orientation and easy to operate with the left hand under or over the lens. Buttons, sliders and levers can be appropriate for Setup and Prepare Phase adjustments where you can look at the UIM to operate it. Buttons and levers on lenses are extemely frustrating (because you can't find them by feel) if you want to use them in Capture Phase and also want to use portrait orientation and/or switch from under to over holding.
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| Photo 6 Forced Hold |
* User interface module design Please see Parts 4, Functional anatomy, 10, Operating Systems and 12, Mockups for discussion about this. The precise shape, size, configuration and position of UIM's is critically important for good ergonomics.
* Main control dial: index finger or thumb ? Some cameras locate the main control dial for use by the right index finger, others locate it for use by the right thumb. Some cameras have both, some have neither, some locate the dial where no human appendage could usefully reach it. One recent camera release has three unlabelled dials each operated by the thumb with no dial allocated to the right index finger. As with most things ergonomic there is obviously no general agreement. My research shows that the right index finger is the only finger which is allocated entirely to operating duties with no gripper duty at all. Logically it follows therefore that the right index finger is the most appropriate one to operate a main control dial. Please note this ergonomic analysis is unrelated to any person's likes, preferences or experience. For the record, I have owned and used cameras with main control dials in a variety of different places and have made mockups with the main control dial and other UIM's in a variety of places often moving them by as little as one millimeter to find the best location. My conclusion from this research is that:
IF, and it is a big if, the shutter button is optimally positioned, the best location for a main control dial is about 13 mm behind and at the same height as the center of the shutter button, angled to align with the position and movement of the right index finger. A reverse configuration would also work well, in other words, switching positions of the shutter button and control dial.
The two worst places I have encountered are: (a) On the upper part of the front of the handle where the control dial is covered by the right middle finger and therefore inaccessible without completely releasing grip with the right hand. (b) Right under the thumb at rest position which prevents you from holding the camera securely without bumping the dial.
If the camera has a well designed, configurable quartet of UIM's available to the right index finger and a JOG lever easily reached by the right thumb, then only one control dial is required.
Photos 1 and 2 ( NC indicates a button which could usefully be user configurable but which is not) These illustrate an exercise in UIM analysis of a camera based on photos of the device and perusal of the user's manual. This superzoom camera with 19 buttons and 2 dials, is clearly aimed at the Level 4 user and will generally be used with the EVF, as maximum stability is required for the long lens. There is a decent handle and a thumb rest which appears to be of adequate size. The area occupied by the Made in Japan words is the rest position for the thumb, properly devoid of any UIM's. So at least you can hold it properly without accidentally pushing a button or dial. The function of two buttons, fn1 and fn2, can be set by the user. Unfortunately the other 17 buttons on this camera are not configurable and can only carry out functions preset by the maker. There are five buttons on the left side of the monitor. This is a satisfactory location for UIM's required in the Setup, Prepare and Review Phases. However 2 of them, ISO and AF are required in Capture Phase. To use them the operator has to drop the camera down from the eye, take the left hand off the lens, press the button, return the left hand to the lens, shift the right hand from the grip position, operate the control dial or four way controller, return the right hand to capture position then at last take the shot. If most of the buttons on the right side, particularly those in the highest priority zone adjacent to the shutter button and assigned to +/-and Continuous shooting were user configurable, you could allocate ISO or AF to one or both of these and dramatically improve the ergonomic experience. There are many other issues with this camera's HMI. There is plenty of space for a JOG lever but none is provided. There appears to be no option (I might be wrong about that) to assign AF start to one of the back buttons.
This camera is large enough and has enough UIM's to have been capable of excellent ergonomics with more thoughtful HMI design and function allocation. Instead it represents a missed opportunity to create a really good user experience.
Photo 3, Set and See Dials This camera has easily visible, quickly adjustable Set and See dials and levers on the top plate for adjustments in the Prepare Phase of use. This represents optimum ergonomic use for Set and See modules All is not wonderful with this camera however. The red dot button, which is located in a high priority zone easily accessible to the right index finger, cannot be assigned to anything other than movie start. The silver button behind it does have user assignable function but is flush with the surface, making it almost impossible to find by touch.
Photo 4 Natural Hold 1
This is a small camera with a Projecting Handle. This type of handle works reasonably well on medium sized DSLR's, but shrinking the handle to fit a smaller camera does not shrink the hand which holds it. If the hand is held in the "Natural Half Closed" position as shown here the index finger does not fall onto the shutter button and the ball of the thumb is not on the thumb rest or the AEL/AFL button.
Photo 5 Natural Hold 2
The mockup shown here is actually smaller than the real camera but was designed around the "Natural Half closed" hand position. In other words the design process started from the hand and it's functional anatomy, not from any preconceived idea of style, shape or size. As a result it fits comfortably in that hand with the fingers exactly where they need to be to operate the key controls in capture Phase.
Photo 6 Forced Hold
In order to operate the camera in Photo 4 it has to be held this way. This is ergonomically suboptimal with a weak grip and cramped hand position.
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