Locations

CAMERA  ERGONOMICS

Part 8,  Locations

Author  AndrewS 



Photo 1 Holding the Mockup

Form and function       A modern electronic camera can have any shape and configuration at all.  It would be relatively easy for manufacturers to produce cameras shaped like a spheroid, a prism, cylinder or any other simple or complex shape.

Whatever it's shape a hand held camera will always be used by someone's ...... yes, you guessed it.........hands    and those hands do not change their size, shape or function  to conform to changes in camera design.   The design has to accommodate the hands, eyes and brains of it's users.

For the purposes of this discussion I will use a mockup with a fairly conventional layout. It has an efficient general configuration. The position and relationships between camera body, monitor, EFV, handle and most controls would all be immediately recognised by most people as a camera.

Camera real estate    Ask any real estate  agent the three most importand determinants of the value of a house.  The answer will be "position, position, position".  Camera real estate is just like that.  The user interface modules by which a camera is controlled have to be disposed around the camera body in some arrangement.

Some locations have a  high value because they are most easily reached by the right thumb and index fingers. To these locations we should allocate tasks of the highest priority in the Capture Phase of camera use.    Locations which are more difficult to reach can be assigned tasks for the Setup Phase of camera use. Please refer to Parts 9 and 10 for detailed discussion about the phases of camera operation.

I have identified four levels of  location value, High, Hi Medium, Lo Medium and Low.

The Mockup  Please refer to Part 13 for detailed discussion of the mockup used.

Assumptions  This discourse assumes we are dealing with a hand held camera suitable for use by a person who likes to take control of the photographic process.  In other words an expert, aspirational snapshooter or professional user.  The mockup has been designed and built by the author to represent the best size and configuration for a compact (mirrorless) interchangeable lens camera. It is optimised for an adult with average sized and shaped hands but the design allows easy use by people with larger or smaller hands.

This camera could also be quite suitable for a snapshooter when set to fully automatic mode. In this case most of the external controls would be rendered inoperative. Should the snapshooter desire to upgrade his or her photographic skills (s)he can do so using the same camera.

Photo 1, Holding    This photo shows the author's right hand holding the mockup camera. This is the starting position with the thumb sitting comfortably in it's indented space and the index finger resting on the shutter button. The other fingers are gripping the handle.

Notice the position and  orientation of the interface modules. The mockup might look a bit rough but the precise location of the control modules has been developed through many trials for optimum efficiency. The exact distances in millimeters between the modules and their exact layout is the result of many trial mockups.  This iteration represents a high level of synchrony between the functional anatomy of the hand and the detailed design of the device.

Locations Mockup Top

Photo 2,  Locations Mockup Top       Here is a closer view of the top of the camera. I have identified a group of four control modules as having "High" location value.  With reference to Sections 4 and 6, I have shown that the right index finger can easily and quickly operate four modules in this location, by feel, without having to look at the camera, while continuously looking through the viewfinder and without moving a muscle of any body part except the index finger.  This is an ideal location for tasks of the Capture Phase of operation. It is particularly well suited to primary and secondary exposure control tasks.  On this mockup the modules are Shutter Button (user assignable function), Main Control Dial (function depends on operating and/or shooting mode),  Button 1 (user assignable function), Button 2 (user assignable function).

Next comes the group of modules identified as having "Hi Medium" location value. Modules in this area can only be reached by releasing the right hand's grip on the handle and supporting the weight of the camera and lens with the left hand. On the mockup I have used this location for a Main Shooting Mode Dial and a subdial Drive Mode lever. These two modules are used for tasks in the Prepare Phase of camera use.

On the right side at the top are two modules, buttons, in this case, labelled "Lo Medium" value.  Of the four buttons in a row, the front two are easily reached by the index finger without changing grip.  However  a substantial shift in grip is required to get the tip of the index finger onto the third button even though it's center is only 12 mm behind the second button.  These modules are suitable for tasks of the Setup and Prepare Phases of operation. The tasking of modules in this location should be user assignable.

Photo 3 Locations Mockup Rear

Photo 3, Locations Mockup Rear     The rear of a modern electronic camera is a busy place so everything has to be positioned very carefully, so the user can operate the device efficiently while holding it.

Let us start with the locations I  have designated "No Controls".  I once had a camera with buttons along the bottom, beneath the monitor. Bad idea. When I did want to reach one of those buttons it was awkward. I had to lower the camera and  release the left hand from the lens to get a finger on a button. But if I left the camera switched on while carrying it on a neck strap, those buttons got pressed accidentally all the time.

The second location which must be free from control modules is shown on the right side. Most of this is left clear so the thumb can find a secure rest place without forever bumping into a control module.  I once had a camera with a main control dial located where I have indicated "Not Here !!!" in Photo 3. Trying to use this camera was  one of those "I can't believe they did that"  experiences. Whenever I tried to hold the camera securely my thumb impinged on the control dial, causing unwanted alteration to a camera status parameter.

Another  place where control modules should not be located is on the thumb rest. Buttons in this location are often pressed accidentally when the user is picking up or carrying the camera.  There are many complaints about this on user forums. I have a DSLR with two recessed buttons at the upper end of the thumb rest.  The recess usually prevents them from being actuated inadvertently. However it is easy enough to find better ways of implementing the functions which they serve.

I have designated two very specific locations as having "High" value. Please refer briefly back to Photo 1 for the position of the thumb in the basic rest hold.  Without significantly disrupting either thumb opposition or the purchase of the right hand on the camera, the right thumb can move a short distance to the left or right side, and can be pressed forwards, into the body of the camera, without flexing.

The module to the left side of the thumb is a JOG type lever which can be pressed in and/or moved laterally in any direction . To the right side is a button sitting against the side of the thumb rest. This is easily activated by moving or rolling the thumb slightly to the left. The function of this button is Mode dependent and user assignable to some extent. These two modules are well located to provide primary and secondary focussing controls in the Capture Phase of operation.

Next we have a group of interface modules to which I have designated "Hi Medium" location value. To activate these modules the right hand must be disengaged from it's basic grip, and camera support duty taken by the left hand.  However the right hand does not have to move very far so modules in this area can be operated quickly. Prepare and Review Phase tasks do well here.

There are two zones labelled "Lo Medium". Those in the lower part of and the yellow buttons below the four way controller are very suitable for Review Phase tasks.

Several cameras locate buttons on the left side of the monitor. This is a suitable place for Setup  and Prepare Phase tasks.  It is a very bad place for Capture Phase tasks. Some camera makers do not understand this and routinely locate controls for ISO and AF Zone movement on the left side of the monitor. For further discussion about this  please refer to the photos with Part 2 of this series.

Cameras with swing out monitors cannot have buttons on the left side of or below the monitor.

Last we have the green buttons which I have labelled "Low" value. These can be accessed with either the right or left thumb but not while the camera is in the process of  making photos. They are best suited to Setup Phase tasks.

All the control modules on the camera rear should be amenable to user configuration with an extensive list of options for each module.

Viewfinder location  On the mockup in the photos you can see I have placed the viewfinder (VF) close to the top left corner of the camera back. I did a lot of experiments with VF locations on different mockups and selected this as the optimum location when the camera is held in landscape (horizontal) orientation. In portrait (vertical) orientation an EVF in either SLR style location (top center) or rangefinder location (top left) will work equally well. As most still photos and almost all video capture use landscape format this means locating the EVF top left gives the best ergonomic result.         The benefits of this location are

* It allows the user to look straight ahead while viewing through the VF and if desired keep the left eye open to scan a broader view of the scene.

* It allows the top left corner of the camera to be pressed into the nasal and orbital bones of the skull for maximum stability.

* For right eye use it keeps nose grease off the monitor.

* It is no worse and maybe better  for left eye use than a VF located in standard SLR position.

For optimum effectiveness there are some specific ergonomic design requirements. The optical centre of the viewfinder is best located approximately 20-25 mm in from the left side down from the top plate of the camera body. The eyepoint needs to be set so the cornea of the eye is located the correct distance from the VF eyepiece when the camera is held in viewing position. There needs to be a soft rubber or similar guard around the VF eyepiece to block out stray light and center the eye on the optical axis of the VF.