Kamis, 01 Maret 2012

Handles and Holding


CAMERA ERGONOMICS
Part 7   Handles and holding
Author  AndrewS

Photo 1 Five Handle Mockups
Early days    In the early part of the twentieth century, press photographers used large format Speed Graphic and similar cameras. By modern hand held camera standards, these things were huge, requiring one or more large sturdy handles so the user could support and operate the machine at the same time.   When medium format users took their equipment out of the studio and off  the tripod, they too, soon realised the benefit of a sturdy handle.
35mm    Rangefinder and SLR cameras for 35 mm film managed well enough without handles for many years. But camera bodies grew in size and weight with autofocus, motor drive, batteries and electronics. Heavy telephoto lenses became readily available.
The Canon T90 of 1986, known by users as "the tank"  was one of the first SLR's with a built in handle. This camera was very influential in setting the shape and style of most SLR and DSLR cameras right up to the present time. So great has this influence been that I think it is fair to say the T90 set the shape regarded by many people as that of a "proper camera". As a result, many cameras which are not SLR's or DSLR's and are not "tanks" but are in fact quite compact, have been graced by their designers with a handle similar to that on a big DSLR.  The ergonomic consequence of this has been unfortunate, as detailed below.
Types of handle     My research has concentrated on cameras for the mass market.  This includes DSLR's with sensors up to 24 x 36 mm, Compact System Cameras and Advanced Compacts with fixed lenses.  Some medium format DSLR's have large, elaborate handles which I have not studied.
I have identified four  basic camera handle types. These are No Handle, Mini Handle, Projecting Handle and Parallel Handle. Intermediate varieties are not uncommon.

The sucess or otherwise of any  handle is strongly influenced by several factors. These include handle width, height and shape. The exact location of the shutter button is of crucial importance.  A handle without a good thumbrest makes for a completely unbalanced grip so the position, size and shape of the thumbrest is of great importance. 
No Handle   A lightweight camera not expected to mount telephoto lenses, covered in non slip material and with sufficient space on the right side of the lens and monitor screen, can function reasonably well with no handle.  Some cameras feature a small bump or raised section on the front of the right side of the camera body. I regard these as a variant of the no handle type.
Mini Handle  As I write this in February 2012, there is a contest between manufacturers to produce ever smaller camera bodies. Many of these have insufficient space on the right side of the monitor for a comfortable thumb rest and insufficient width for a decent sized handle. So they get a mini handle, perched close to the right side of the body. The shutter button is often on the top plate of the camera, also located close to the right side. The result is a camera which does not provide secure purchase to the fingers of the right hand, which must be cocked back away from the right side of the camera body, leaving a space between the camera body and the palm of the hand. This gives an insecure grip requiring the left hand to provide almost all the support function for both camera and lens.
Projecting Handle   This is the type to be found on most DSLR's.  It  requires the hand to adopt an "opened" grip.  It works well on medium and large camera bodies which have a large enough handle to allow the hand and fingers to spread out to a comfortable position. The precise location of the shutter button and the exact sculpted form of the grip are of critical importance.
On small cameras the projecting handle is unsatisfactory for the simple reason that the hands which use the camera do not shrink to fit. Small DSLR's styled to look the same as medium and large ones do not have enough space on the right side of the lens for a comfortably contoured projecting handle. Compact System Cameras and superzooms are even smaller resulting in a complete mismatch between the handle shape, shutter button position, hands and fingers. These cameras require a different type of handle design.
Parallel Handle  My work with mockups and actual cameras leads me to the view that the parallel handle type is the best solution for all camera sizes. Basically the parallel handle is a projecting handle rotated 90 degrees anticlockwise (as viewed from above) so it lays along the front of the right side of the camera. Once again it is imperative that the shutter button be  located in exactly the right spot and the handle itself be carefully sculpted so the fingers fit comfortably. When the fingers gripping a parallel handle are flexed the compression force is directed  into the palm of the hand, making for a stable, secure hold on the camera.
The only issue about the parallel handle with which some may find fault  is that it requires slightly more camera width on the right side than the projecting or mini handle types.  However the  potential benefits are great.   In many cases increasing the width of a narrow camera by as little as 15 mm would allow a dramatic improvement in handle design and operating characteristics.    It would also allow the fitment of a larger battery, something many modern cameras desperately need.
Photographs
Photo 1, Five Handle Mockups  These are some of the  mockups I have made in the course of studying handle design. At the back are the Large Projecting and  Large Parallel types. These are DSLR size with a shutter button height of 83 mm. In the middle are the Small Projecting and Small Parallel types. These are Compact System Camera size with a shutter button height of 64 mm. At the front is a No Handle type.
On the large cameras the parallel handle is only 3 mm wider than the projecting type but provides a more closed and secure grip. On the small cameras the parallel handle is 12 mm wider than the projecting version and provides a dramatic improvement in grip.


Photo 2 Projecting Handle Large
Photo 2, Projecting Handle Large  This is a popular handle type which works reasonably well on medium to large cameras. However the open grip hand position is not quite as relaxed or secure as the half closed grip seen in Photo 3.


Photo 3 Parallel Handle Large
Photo 3, Parallel Handle Large   The camera body is the same depth but this type of handle allows the more comfortable half closed hand posture. Finger flexion force is directed into the palm of the hand. This means that when gripped tightly with the fingers the camera becomes more stable with no tendency to twist out of one's hand.
All this is a bit difficult to demonstrate in words and photographs, but is immediately apparent with the mockups in hand.


Photo 4 Projecting Handle Small Natural
Photo 4, Projecting Handle Small Natural   Here is a projecting handle on a small camera. Unlike the mockup in Photo 2, there is no natural way to hold a small camera with this type of handle. For this photograph, I held the mockup with the nearest approximation to a natural grip that I could manage.   You can easily see that my index finger is nowhere near the shutter button. It wants to find a shutter button at  a different location.


Photo 5 Parallel Handle Small Natural
Photo 5, Parallel Handle Small Natural  This mockup camera is the same size as that in Photo 4 but now it has a parallel handle. The ergonomic difference is like night and day. Now the right hand holds the camera comfortably with a natural half closed grip. The index finger falls exactly on the shutter button because I got my fingers comfortably positioned before selecting the optimum position for the shutter button.     The conceptual basis of this design was "Form follows fingers".


Photo 6 Projecting Handle Small Forced
Photo 6, Projecting Handle Small Forced   Many small cameras have a projecting handle, forcing the user to hold them as shown here. To get the index finger onto the shutter the whole hand has to be cocked back at the wrist, an unnatural posture. The palm of the right hand has to pull away from the right side of the camera body, destabilising the user's hold on the camera. It is not possible to firmly grip and to operate this camera at the same time. The left hand has to be placed on constant camera support duty. But the left hand also has to work the zoom collar and at times the  manual focus ring, if available.


Photo 7 No Handle
Photo 7, No Handle  For many years the right side of most cameras using 35 mm film was like this. If there is enough width for the fingers and thumb to find decent purchase on the front and back of the body and the shutter button is inset far enough (on this mockup it is 30 mm which is sufficient) and the surface of the body has a grippy texture and nobody is planning to mount a big heavy telephoto zoom anytime soon, then this design can be fairly satisfactory.


Photo 8 Mini Handle
Photo 8,  Mini Handle   This camera's body width to the right of the lens is insufficient to accommodate a full handle so it got a mini handle. The centre of the shutter button is inset only 20 mm  and there is no thumb rest as the place for a thumb rest is occupied by a control dial. 


Photo 9 Mini Handle No thumbrest
Photo 9,  Mini Handle No Thumbrest  This is the position into which the user's right hand is forced in order to operate the camera in Photo 8.  The palm of the right hand is thrust away from the camera. The wrist is cocked back to an unnatural position.  The lower right rear corner of the body is perched on the centre of the palm. The only body part actually gripping this camera is the middle finger of the right hand.  To add injury to insult, there is on this particular camera a misalignment of exterior body plates at the lower right corner causing a sharp edge which digs into the user's palm.


Photo 10 Getting it Right Mockup
Photo 10, Getting it Right Mockup   This mockup is 7 mm wider and 7 mm lower than the camera in Photo 8, making the two almost exactly the same size. Yet the mockup in Photo 10 provides a dramatically  improved human machine interface (HMI)  It  is a pleasure  to hold. It has an anatomically sculpted parallel handle, the shutter button is optimally placed exactly where the index finger wants to find it and there is a large, secure thumb rest. The right hand and all except the index finger paticipate in gripping the camera which can be operated with the hand and fingers exactly as shown in Photo 10.


Photo 11 Handle Dimensions
Photo 11, Handle dimensions  This is the same mockup shown in Photo 10. The body of the parallel handle is 37 mm wide. The centre of the shutter button is vertically above the left (as viewed by the user) edge of the main part of the handle and sits on the handle not back on the camera body.  These dimensions work well for a variety of hand sizes and shapes. Small hands move up the handle, large hands move down the handle. Both can achieve a good grip.

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