Building Mockups

Part 12  Mockups

Author  AndrewS 

History   My initial interest in camera ergonomics was provoked by the experience of using a Canon EOS 450D and Panasonic G1.   I bought these two cameras  in a quest to downsize from a kit based on a Canon EOS 40D,  a medium size DSLR.  I found the smaller cameras cramped, awkward and difficult to use compared with the 40D. I wondered if it was possible to design a camera about the same size as the G1 but with better ergonomics.

Photo 1 First Mockup Hold

Photo 2 First Mockup Size

So I built my first mockup, shown in Photos 1 and 2.  This turned out slightly smaller than a G1 but provides a hugely improved holding experience. It is a "proof of concept" design, the shape of which bears only passing resemblance to any existing camera. The "concept" which was tested and proved is that the ergonomic problems I had been experiencing with small cameras were due to design rather than size.  Furthermore I demonstrated to my own satisfaction that it is entirely possible to build excellent ergonomics into small cameras if an ergonomic centered  approach is the principal driver of  the design process.

Photo 3 Cylinder Eye level

Photo 4 Cylinder Monitor View

In Part 8 of this series I noted that an electronic camera could be designed to any shape at all. So I trialled a variety of shapes. One which showed some promise at the preliminary mockup stage was "the cylinder".  See Photos 3 and 4.   This is not a new idea. The Canon Jet/Epoca  of 1992 used a cylindrical format. In 2012 the designer Jean-Michel Bonnemoy proposed another variant on the same theme. A camera could be made this shape but I found the layout is not readily adaptable to interchangeable lenses and  the unit must be held up to the eye, with limited opportunities for alternative holding positions.  So I settled on a fairly conventional shape for it's superior ergonomic potential.

Over the last two years I have made five "grip only"  mockups, shown in Part 7 of this series and five full camera mockups, two of which are presented in detail here.  They represent the mirrorless interchangeable lens camera type which I have chosen as I believe it is the way forward for camera design.  Along the way there were many false starts, mockups abandoned part built and many changes to handle shape and size, button location and  viewfinder location.

Concepts   The process of making mockup cameras has taught me a great deal about ergonomic aspects of camera design.  The experience is liberating but also demanding.   I can and did,  put the viewfinder anywhere, the shutter button anywhere, all the other controls anywhere, without restriction. I can and did,  make the device and all its parts any size and shape at all. From all this some useful ideas have emerged.

Photo 5 Size Determinants

Camera body size  Is determined by the following factors:  See Photo 5

* Monitor module size. This in turn is determined by the actual dimensions of the preview/review image, aspect ratio, location of camera status data information on or below the image, fixed, flip up/down or full swing out and swivel type.

* Vertical height of the eye level viewfinder.  This in turn is partly determined by the size of the EVF chip, OVF module or DSLR pentaprism/mirror. It is also greatly affected by the designer's decision about the soft rubber eyecup around the viewfinder, how large this should be, what shape and whether it is fully contained within the dimensions of the camera body or allowed to protrude beyond the body.

* Width of the control panel. This is the part of the rear of the camera between the right side (as viewed by the user) of the monitor module and the right edge of the camera body.

* Inset of the optical axis from the left side of the camera body.  The further the optical axis is from the left side, the wider the body must be to make room for a handle and thumbrest.

* Handle and thumbrest size and configuration.

Lens size   Is principally determined by imaging sensor size.

Size does matter after all    I discovered that with good design a small camera can have excellent ergonomics. But there is a size range below which it becomes increasingly difficult to achieve functional harmony between the device and the hands which operate it. That size is achieved by the small mockup described in this section. With smaller units,  holding, viewing or operating inevitably suffer as there is simply not enough device real estate available for the requisite user interface modules.

Photo 6 SLR Style Schematic

Photo 7 Rangefinder Style Schematic

Shape matters   Very early in the gestation process of a camera design decisions are made about the basic shape and layout of the device. These decisions are "baked in" to the design and are the main factors which determine ergonomic performance of the final product.  For instance some mirrorless cameras have the shape of a small SLR even though there is no functional reason for them to be that shape.  See Photos 6 and 7.  These schematics illustrate two cameras, each the same width and height.  The Rangefinder Style version has the viewfinder optimally located and permits greater shutter button height which in turn allows the creation of a more secure handle design. In addition the lens axis on the rangefinder version can be moved further to the left, making room available on the front of the body for a more substantial handle.

Photo 8 Crafting Mockup

Method   I start with some basic dimensions of monitor module width and height, viewfinder height, body depth and rear control panel width. These derive from actual cameras which I have used.  I cut a piece of wood to the dimensions of the basic body then start crafting a handle and other parts. These can be seen in Photo 8.  I cut and shape the handle separately then screw and glue it to the body for final shaping. I selectively cut, file and sand some parts of the structure, then add to other sections with polyester cement, gradually building up a shape which slips easily into my hand when it is held in the "half closed, relaxed" position described in Parts 4 and 6 of this series. There is a great deal of trial and error in the process with many suboptimal versions being discarded. User interface modules are positioned and repositioned sometimes moving by as little as one millimeter to get them in the right place for optimal finger access.

The mockups may look a bit rough but the precise size and shape of every part and the precise size, type and  location of every interface module have been very carefully evolved over many trials.

Shaping is always guided by the "Form follows fingers" principle.

The lenses are plastic peanut butter jars chosen for size to represent typical standard zooms.

Aesthetics    I do take a hard line on ergonomic excellence and have  a low tolerance for ergonomic mistakes. However I am also acutely sensitive to aesthetic aspects of design.  This sensitivity is incorporated in all my mockups which emerge from the creative process with their own unique style signatures.

Exposition    Here I present two mockups, identified as "small" and "large".

Photo 10 Small Front

The one named "Small" is a good size for a consumer level mirrorless interchangeable lens camera with micro four thirds or APS-C sensor.  I made the body depth suitable for a flangeback distance in the range of about 20-25 mm. Dimensions allocated to the monitor would provide for a fixed type with an image diagonal of 75 mm or a swing out type with smaller image size.  A swing out monitor with a  75 mm image diagonal would add approximately 6 mm to the height and 12 mm to the width.  Overall dimensions of the body are Width 124 mm, Height 80 mm, Depth 55 mm. This is only marginally larger overall than a Panasonic G3 yet delivers dramatically better ergonomics. The control panel is more than twice as large, allowing a comfortably angled thumb rest and much larger control modules. The handle is fully contoured and accepts a full five finger grip with average size adult male hands. The main control dial is comfortably operated by the right index finger. The lens shown is about the size of a typical f3.5-5.6 standard kit zoom.

Photo 9 Height Comparison

The "Large" mockup represents an advanced level  mirrorless camera suitable for micro four thirds, APS-C or even 24x36  mm full frame, with large aperture zoom lenses.  The dimensions are Width 142 mm, Height 90 mm, depth 68 mm. Note that the height is the same as a Panasonic GH2 and the depth slightly less. This means the large mockup will easily fit into the same space in a camera bag as the GH2.  See Photo 9.  Yet it has a much larger and more comfortable handle, much larger and more naturally angled thumbrest and a control panel almost three times the area of that on the GH2. All this adds up to a massive improvement in holding, viewing and operating.  The lens shown is about the size of a pro style f2.0 - 2.8 zoom.

Photo 11 Large Front

The basic shape of both mockups could be described as "rangefinder style with handle and thumbrest", as distinct from "DSLR" shape. This was chosen for fundamental ergonomic reasons. The eye level viewfinder is located near the top left of the body (see Part 9). Both mockups share numerous design features.

They each exemplify a set of ergonomic design principles detailed in Parts 1-11 of this series. In summary these are

* Style follows function

* Form follows fingers

* Specific operational tasks of the four phases of camera use. These are Setup, Prepare, Capture and Review.

* Specific requirements and analysis of the three tasks of camera operation in the Capture Phase. These are Holding, Viewing and Operating.

The EVF is located as described in Part 9.

The Handle is located and shaped as described in Part 7.  Both mockups use the parallel handle for its distinct ergonomic advantages.

The Thumbrest  I regard the thumbrest as of crucial importance in the total ergonomic design. It is the critical feature which if correctly designed allows the user to hold and operate the device simultaneously. If ill conceived and executed it prevents the user from so doing. Many compact and compact system cameras are so small that there is not enough width on the rear of the camera to fit a properly shaped and positioned thumb rest. So the user is offered no thumbrest, or a control dial where the thumbrest should be, or a vestigial bump way over on the right side (as viewed by the user) of the camera leading to a cramped, unnatural hand/finger position.

Photo 14 Small Hold

Photo 15 Large Hold

Hold Position, right hand   In Photos 14 and 15 you can see the basic right hand camera hold position. Camera operation starts from this position. Note the relaxed half closed posture of the hand as described in Part 4. Note that there are no interface modules located where the thumb or middle, ring and little fingers rest. The AF start button on the large version is beneath the terminal phalanx of the thumb but will not be pressed accidentally as a small but definite flexion of the interphalangeal joint is required to impart pressure on the button. There is a quartet of modules beneath and ready to be operated by the index finger which does not have to grip the camera.  

Corners  The exact amount and shape of rounding the corners was determined after much experiment. You will notice there are no sharp edges or corners on either mockup and few flat planes other than the monitor and base. This shape was determined by feel not some preconceived style. However the result turns out to have it's own unique style which is not derivative of some abstract concept or a 1980's film camera.



Photo 12 Small Rear

Photo 16 Small Top

User Interface Modules   A great deal of thought and experiment has been expended in designing the type, position and function of the interface modules (see Part 10). They are located in high, medium or low priority camera real estate areas (see Part 8) , depending on their function in the four Phases of use. Photo 16,  Small Top and  Photo 12,  Small Rear show the interface modules.

The interface modules are in ergonomic functional groups.

Group 1  Right index finger, Capture Phase.   See Photos 14, Small Hold and  15, Large Hold.    The modules in this group are Shutter Button, Main Control Dial, ISO button and Exposure Compensation button .  Once the camera has been configured in Setup and Prepare phases it can be driven with this group while continuously viewing through the EVF and without changing grip with the right hand. The left hand will take care of zooming and manual focus if required. The right index finger can start/lock autofocus and auto exposure, change aperture in A Mode, shutter speed in S mode and program shift in P mode, change exposure compensation then capture the image. In M Mode pressing the Exposure Compensation button toggles between aperture and shutter speed adjusted by the main dial. One does not need any exposure compensation function in M Mode. It is not necessary to have one dial for aperture and another for shutter speed.

Group 2  Shooting Mode Dial and Drive Mode lever. This "set and see" control layout makes all the main shooting modes and drive modes visible at a glance and able to be altered quickly and directly, with no need to enter a menu. With more space available the large mockup also has a focus mode dial/area lever located on the right side of the top plate.  These dials/levers control  major Prepare Phase settings.

Group 3  Right thumb, Capture Phase.  There are only two modules in this group, the  JOG lever and the AF start/lock button. These are located so they can be operated by the right thumb without disrupting grip. This means the thumb has only to move a very small distance left or right and only a very slight amount of flexion of the interphalangeal joint is required. (see Part 6).

The JOG lever is a major interface module, the function of which is mode dependent. See Part 10.  I believe all cameras designed for controlled use should have a well designed JOG lever. It is imperative that the JOG lever be correctly located in three dimensions.

Photos 12 and 16  show correct location of a JOG lever on the small mockup. My right thumb goes directly onto the JOG lever  when moved slightly to the left of base position. Note also in Photo 16  the JOG lever stands 6 mm proud of the camera back. This means the ball of user's thumb will press directly on the JOG lever with the thumb straight and without impinging on any other control module.

I regard the  AF start/lock button as another vital interface  module on a camera designed for user control. Unfortunately it is missing from many cameras. On the mockups it is positioned so it will be activated by a small movement of the right thumb, but will not be easily activated inadvertently. The AF start/lock button should be user configurable as auto exposure lock/autofocus lock, AF start or Video start with the shutter button function configuration to complement that of the AF button.

Group 1 and 3 modules are placed at high priority real estate locations on the camera.

Group 4   With reference to Photos 12 and 16, this group consists of button #3 on top and buttons #5, 8, 9, 10, 11, 12, 13 on the rear. Interface module layout on the large mockup is very similar but without the numbers.   These are direct interface modules for the Prepare Phase of use.  See Part 11.  On a production camera several of these would have a label, some would be un labelled.  All would be able to accept a user assigned function  from the full list of functions of which the camera is capable.

These are in medium priority real estate locations.

Group 5   With reference to Photo 12  this group consists of  buttons #13, 14, 15  applicable to the Review Phase of use.

Group 6  In Photo 12  This group includes buttons  #4, 17, 16.  These are placed in low priority real estate locations and are applicable to the Setup Phase of use.  I would  allocate the Main Menu to #17 and use #4 and 16 for user configured tasking.

Summary   These mockups incorporate the results of  my thinking and research on ergonomics described in Parts 1-11 of this series. They represent modern electronic cameras which encourage the practiced user to drive them like a sports car. Fast, accurate, enjoyable.