Lens based controls and the left hand

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.