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Small camera left hand under lens. A comfortable position with the camera held low for monitor viewing, as shown here.

 

Much of the discussion in the last ten posts has been about the role of the right hand in driving a camera. This is largely because there are, to my knowlege no left handed cameras and as far as I am aware there never have been.

Because cameras are right handed most of the high value UIM's are clustered on the right side and are operated by the right hand. I like to think of the right hand as being captive. If the camera has an anatomical handle and a well designed set of control modules, the right hand fits into a carefully defined place and can fit nowhere else. The possible functions of the right hand are closely prescribed.

A left hand position like this is more likely to be comfortable with the camera held up to the eye.

The left hand however has many more degrees of freedom. I like to think of it as the rover. It can be held under the lens, over the lens, around the left side of the body or under the body. The position of the left hand relative to the camera and lens changes 90 degrees when the camera is turned from landscape to portrait orientation. The left hand will find a different relationship to the camera when moving from eye level to monitor viewing.

The left hand has holding, supporting and operating duties often all at once.

With a larger lens like this and eye level viewing the left hand over position is likely to be comfortable.

Lens based UIM's User interface modules on the lens need to be easy to for the left hand to find and operate in any of the varied relationship positions above. When designing control modules for the right hand I literally do sometimes find that shifting one 1mm makes a significant difference. The situation with the lens is quite different. 

Capture Phase I have found that the most reliable type of UIM for Capture Phase actions on lenses is the circumferential ring/collar type which can be located and operated with the hand and /or lens in any orientation. The usual functions allocated to circumferential controls are manual focus, zoom and aperture. These are primary Capture Phase functions.

Prepare Phase Some lenses have many other UIM's. These can control OIS (VR) on/off, AF/MF, focus distance limiter and many others on some high grade long zooms. In general, buttons, levers, switches, small dials and sliders work best for Prepare Phase actions. The reason for this is that these types of UIM are difficult to find and operate by feel given the many different relationships between lens and hand which can occur.

Power zooms These are generally intended for motion picture use in landscape orientation with monitor view. Within that limited envelope of circumstances switches, sliders and the like usually at about 10 o'clock on the lens barrel as viewed by the user can work well. But if you flip such a lens over to portrait orientation the zoom slider becomes very difficult to find and operate.

Mixing use phases, functions and UIM type. Some combinations are ergonomically suboptimal, to put it mildly. In June 2012 I posted an analysis and critique of Samsung i-Function. This is a process which requires the user to juggle the camera while shifting grip from the right hand to the left and back, and in the process pressing a button on the lens, looking in the viewfinder, rotating the focus ring then pressing a button on the body. All this to make adjustments which in every case could be made much more efficiently with the direct controls already on the camera body.

　

Birds in bushfire smoke

 

Autofocus for interchangeable lens cameras was invented in the late 1980's. One of the many challenges facing AF engineers was finding a way to move the active AF area from one position to another. In 2008 mirrorless interchangeable lens cameras arrived on the scene. These enable autofocus right on the imaging sensor. They can therefore be designed to allow AF anywhere on the frame.

In the early days of autofocus Some cameras could only AF in the center. This led to the strategy of "focus and recompose" which some people still use.

Eye control AF was used by Canon in several SLR models in the film era. I had one of these for a time. The technology worked but was prone to focussing on a point adjacent to the one desired and there were issues with calibration. So this feature was soon discontinued. I suspect one of the complicating factors was the way our eyes actually work. When we look at something our eyes are always scanning in little skips. They do not rest on one spot for more than a fraction of a second. So, I do not anticipate a return to eye control any time soon.

Touch screens It seems every kind of device these days has a touch/swipe screen. Even motor vehicles have them, creating a highly dangerous source of driver distraction.

The distracted photographer is unlikely to kill anyone but touch screens on cameras face a problem similar to that on cars. Just as the car driver should be looking out the front windscreen at the road ahead, the photographer needs to look through the viewfinder at the subject ahead. In each case having to attend to a touch screen is a distraction from the main task. There are also simple physical problems. It is effectively impossible to get a finger onto the screen with the eye to the viewfinder. Panasonic has a feature called Touch Pad AF. This allows the operator to move AF area by touching the screen while looking through the EVF. I found it impossible to use effectively although I have had feedback from one reader that he was able to make the feature work on the Panasonic GX7 with it's EVF at the top left corner. The touch screen works quite well on a tripod mounted camera as you don't have to hold the thing as well as access the screen.

Hard user interface modules (UIM's). Some cameras have a complicated rigmarole by which the AF area is moved up/down by the front dial and left/right the rear dial. Or maybe it was the other way around, I forget. I once had a Canon SLR which used this system. There was a great deal of button pushing and dial turning. It was so clumsy I gave up and used focus (with the center area) and recompose.

Many cameras these days use a 4 way controller located on the lower part of the control panel on the right side of the camera for AF area movement. This works quite well if set up properly so the AF area moves immediately when one quadrant of the controller is pressed. However this arrangement does require the user to release grip with the right hand in order to operate the 4way controller. This is not a tragedy but some method not requiring the right hand to change grip would be better.

Some high spec Nikon cameras use a kind of mini 4 way controller a little higher up on the control panel. This is more accessible and therefore an improvement. Some Canon cameras use a "Joystick" in a very similar location, again an improvement over the standard 4 way controller.

The JOG lever is the UIM nearest the EVF. It is larger and more prominent than the regular buttons. It needs to have a highly textured profile to make it easy to move in any direction with the thumb. Below and to the right of the JOG lever is a "return to center" button.  Above and to the right of the JOG lever is the AF ON button. The top photo shows the hand/thumb  position required to operate the JOG lever. The lower photo shows that to operate the 4 Way controller the user's hold on the camera with the right hand must be partly released.

The JOG lever This is a generic term for the Canon Joystick. If optimally designed and positioned this should provide the best ergonomic solution to the problem. The JOG lever is always on. This means it moves the AF area immediately when pushed up/down or left/right. It is operated by the right thumb. The best position is such that the distal pad of the thumb falls directly onto the lever when it swings to the left from the basic hold position.

In my work with mockups this has led to an issue which could be a problem. Every time I go through the exercise of locating UIM's on one of my mockups the best position for the JOG lever ends up right on the top right corner of the monitor screen. If the JOG lever were to be placed there it would necessitate chopping off the top right corner of the monitor screen housing. I don't know if there is some engineering reason why this should not occur, but I suppose it might clip off the top right corner of the preview or review image in some aspect ratios. Some users might be sanguine about this others might not.

In the event I have located the JOG lever on my recent mockups 10mm above the position I regard as ideal. This is probably satisfactory for most users but some with small hands or short thumbs might have to shift grip slightly to get their thumb far enough over the top of the lever to tbe able to operate it.

Not withstanding these concerns I think the JOG lever is the optimum solution if it can be well implemented. It can also undertake selection and other duties in Setup, Prepare and Review phases of use.

　

　

Canning Stock Route, Western Australia

 

I am seized with robust enthusiasm for the latest in touch/swipe screen devices like the Microsoft Surface which recently arrived in our house. But a proper camera has to be operated while looking through the viewfinder. So it has to be controlled by direct finger interaction with hard interface modules, in the form of dials, levers buttons and the like.

An inverted L shaped handle can have a substantial top deck which can host some key user interface modules (UIM's) for adjusting primary exposure parameters in Capture Phase of use. It would be a waste of top value camera real estate to locate UIM's which control Setup, Prepare or Review Phase items in this area.

These UIM's are operated by the right index finger, ideally without the user having to move a muscle of any other body part.

The configurable camera There is a multitude of modes, functions and features on a modern camera. Any individual user will have his or her own ideas about which ones to bring out onto the hard buttons and which ones to leave in a menu. Therefore most of the hard UIM's must allow the user to select from a long list the function to be assigned to each.

As outlined in a previous post, each Phase of use brings with it a task list. The tasks of Capture Phase present the highest demand for speed and efficiency.

The fingers of the right hand can be categorised as having gripper or operator duties. The index finger is the only one with no gripper duties at all so we should assign to it operation of the UIM's controlling the highest priority Capture Phase tasks. My work with mockups and experience with real cameras leads me to the view that the index finger can effectively manage 4 UIM's. Here is my suggestion about which ones should best be allocated to the index finger:

1. Shutter button. I think just about everybody would agree on this one. Maybe with an on/off lever around it.

2. Front control dial. Most cameras with a front control dial locate it close to the shutter button. Well, the usable ones are close to the shutter button, anyway.

3. Button 1. I would assign ISO to button 1, others will have their own ideas.

4. Button 2. I would assign exposure compensation to button 2, other will have their own ideas, which by the way will likely change with time and experience.

How should these UIM's be disposed on the top deck ? I have spent much time experimenting with the locations of UIM's on cameras. I sort of blundered into the quad control group layout by accident on my second mockup. Please refer to the photo and caption.

This is my second camera body mockup.  I shaped the handle then located the shutter button and control dial where my index finger wanted to find them. That left a space on the right side of the top deck so I put some buttons there.  Later I realised that I had serendipitously created a quad control set including the shutter button, control dial and buttons 1 and 2.

Each of the 4 UIM's has it's own distinctive shape and deliberately strong texture so they can easily be identified by touch. Buttons on the more recent mockups are Phillips head screws which have a nice strong texture. The shutter button and control dial are higher than buttons 1 and 2. Thus the 4 UIM's are fairly close together but none will be activated in error. The precise position of each UIM in 3 dimensions is important. The buttons and dials on my mockups are significantly larger and more prominently textured than those you usually encounter on actual cameras. As a result they are easier to find and operate with the fingers which must use them.

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The four photos above show how the index finger operates the quad control UIM set. It can do this without the need to shift grip with either hand and without needing to move any other finger or part of the right hand.  Access to the rear two buttons (3 and 4) requires a substantial shift in the right hand grip.  Therefore they are used for adjustments required in Prepare Phase not Capture Phase. I could have used a small set and see dial in that position, like you see on the NX30 below, but that would remove a substantial element of user choice about functions available in Prepare Phase.

The Quad control group allows the user to drive the camera most of the time with just the right index finger. It can do the following quickly and smoothly:

* Shutter button: Initiate AF and AE, hold AF and/or AE (with half press) and capture the shot.

* Control dial, directly: Change aperture (in A Mode) or Shutter Speed (in P Mode).

* Button 1: Change ISO (or another parameter if selected), by pressing button 1 then rotating the control dial.

* Button 2: Adjust exposure compensation (or another parameter if selected), by pressing button 2 then rotating the control dial.

That's not bad for one finger. Best of all the quad control group is really quick and easy to use. The curious thing is that I have not yet encountered a real camera with precisely this top deck layout. The recently released Samsung NX30 is heading in that direction with regard to the positions (but not the functions) of the 4 UIM's.

Top deck of the Samsung NX30. This actually does have a quad control set but the main problem here is that both the buttons can only have factory set functions, thus negating the benefit which could have been gained by this arrangement. Neither of the functions assigned to these buttons is directed at primary exposure parameters in Capture phase of use.There are other minor issues. The button 2 (Wi-Fi) is out of place and both buttons are too small. The control dial could be angled a bit to better match the lie of the index finger across the top of the camera.

　

　

　

　

 

In a previous post on front dials I wrote that these were often placed in a variety of different places with an apparently wanton disregard for human functional anatomy. Unfortunately I can say the same thing about rear dials.

Just as the optimum placement of front dials can be studied from a functional anatomy perspective so can rear dials. In the previous post I expressed the view that there is an optimum type and location of thumb support. With this in place it becomes possible to explore the optimum placement of a rear dial. Just to clarify I am referring here to mode dependent control dials, the function of which depends on the current operating mode.

Whether the rear dial is the only mode dependent dial or is paired with a front dial makes no difference to it's optimum position on the camera.

I have used cameras and built mockups with rear dials just about everywhere on the top and rear section of the body. There is little to be gained by analysing all the poor or suboptimal rear dial placements. I will just describe what I regard as the optimal position, which is:

On the thumb support as shown in the photographs. If the thumb support has the optimum projection rearwards, is designed to be wide enough and is the optimum shape then a rear dial can be fitted very nicely into the optimal position on the support.

This is my medium sized full featured mockup illustrating optimal configuration of the thumb support and adjacent UIM's. Here the thumb is in basic hold position in capture phase of use. This is the most relaxed/strong position for the thumb and is where the thumb spends most of it's time. The AF start button which can be seen in the photo below can be pressed by flexing the interphalangeal joint  of the thumb.

The thumb is free to move from side to side. Here it has moved to the right side to operate the control dial. The camera is still held securely by the fingers wrapped around the handle at the front. I have not forgotten the left hand but in these photos it was being used to press the shutter of the taking camera. In use a real camera body/lens would be supported by the left hand, making the right hand's job easier.

Now the thumb has moved to the left to operate the JOG lever. This lever is used to directly control position of the active AF area. The thumb has freedom to move up/down left/right to operate the JOG lever.  This means the AF area position can be quickly moved at will while looking through the EVF and without having to shift grip with either hand.

The thumb should be in the relaxed/strong position for holding the camera while previewing and while making photos. The thumb spends most of it's time in this position with occasional excursions to operate the dial and/or other UIM's. If the handle and body are well shaped then:

Without having to change position of the index finger or the other three fingers of the right hand, the thumb can:

* Move from side to side diagonally across the upper rear of the camera and

* It can also flex at the interphalangeal joint, pressing the distal pad into the top part of the camera back.

The optimum disposition of user interface modules which encourage the thumb to efficiently hold and operate the device is shown in the photos.

Here is a Panasonic FZ200. This camera has reasonably good ergonomics but could be improved in several ways.  Here the thumb has been swung to the right from it's basic position to show the location of the rear dial.  The rear dial would be directly in front of the distal thumb pad in basic hold position. The problem with this arrangement is that the thumb support must be quite small  in order to enable the thumb to swing from side to side as it operates the rear dial. Therefore the thumb support is less effective than it could easily be with a different detail design in this part of the camera.

 

The camera which set the shape and style of SLR's and DSLR's to the present day was the Canon T90 of 1986. This had a prominent handle with a control dial behind the shutter button, an ergonomically practical arrangement which you will find on Canon DSLR's to this day. Turn to the rear and you will find another innovation in the form of an early type of thumb support together with an upper and lower row of buttons.

The thumb rest at the rear complements the handle on the front to make the camera secure and comfortable to hold without strain. If well designed and positioned the thumb rest also positions the thumb so it can move easily to adjacent user interface modules (UIM's).

On digital cameras the monitor takes up the lion's share of available real estate on the back squeezing the control panel into a relatively small space on the right side. Therefore the position and shape of the thumb support and the location and design of its adjacent UIM's is of critical ergonomic importance.

I identify two main types of thumb support: the angled and vertical as illustrated in the photos. My experiments with mockups and my experience using actual cameras indicates clearly that the angled type is ergonomically preferable.

This hand has adopted the half closed relaxed posture which I regard as the most effective for holding a camera. It is both strong and relaxed. Both the thumb and index finger are free to move from side to side. The index finger is also free to curl or straighten.

My concepts about the functional anatomy of camera ergonomics start with the half closed relaxed posture of the hand as shown in the photo. This is the natural position the hand adopts when relaxed. From this position the fingers and thumb can function most effectively. When I develop mockups I shape the timber until it fits in my hand with the hand in this position. The hand comes first. The camera shape has to fit the hand. When I shape a camera this way the thumb support always ends up being the angled type. This allows the hand to adopt a strong/relaxed attitude when holding the camera ready for action.

This is the hand/finger posture required to hold a camera with vertical thumb rest located at the right side of the body. This is not as relaxed or strong as the posture in the upper photo. The thumb can only move sideways to the left. The index finger's movements are restricted in both planes. The reader can confirm this by personal examination.

When a camera is fitted with a vertical type thumb support close to the right side of the body the hand is forced into a cramped/squeezing attitude. This is less effective at supporting the camera and restricts the possible movements available to both the thumb and index finger in the service of operating interface modules.


Summary Good ergonomic design is just as easy to implement at the design and construction stage as suboptimal design. The difference to the user experience can be very substantial.

This is my mockup of a full featured medium sized camera. It is, purely by chance the same width and height as the Sony RX10 below. This photo shows the inverted L shaped handle and associated top deck quad control UIM's. This camera is  very comfortable and secure to hold without strain.

Photo courtesy of Digital Photography Review  dpreview.com This is the Sony RX10. You can see that the shutter button is close to the right extremity of the camera forcing the index finger out and away from the camera. In addition the thumb support is also on the extreme right forcing the upper palm away from the camera.

Photo courtesy of Digital Photography Review  dpreview.com Another view of the Sony RX10. If this camera had the inverted L style of handle the shutter button could be located in the vicinity of the black X. This would greatly improve the index finger position and allow for an improved layout of UIM's on the top deck.  This camera would also benefit from a more oblique thumb support as discussed in the next post.

Mockup compact camera. This one is the same width as and only 2mm taller than a Sony RX100 (II) to allow for the inbuilt EVF. The oblique type handle improves the holding and operating experience.

Holding the mockup compact. You can see how the middle finger wraps around the oblique handle. The relationship between the hand and camera here is completely different from that seen in the photo below.

Holding the medium sized full featured mockup.  The hand and fingers wrap naturally around the body and handle because the mockup was designed to fit the hand, not the other way about. The overhanging top part of the handle allows the middle finger to support the weight of the camera without strain. The upper surface of the top of the handle provides a platform for the quad control UIM system which I will describe fully in a subsequent post. The shutter button is in the optimal place because I put the finger there first then shaped the upper handle and  located the button to fit. Users with smaller hands find a good fit by moving their hand upwards on the handle. Those with larger hands adopt a lower  hand position. The handle is designed to incorporate these requirements.