Kamis, 18 Desember 2014

LX100 Controls Part 7 Prepare and Capture Phases of use

LX100. High subject brightness range, high level of perspective correction.


This was to have been   a five part series but looks like it it will run to 7 or 8 parts. So be it.

I identify four phases of camera use.  These are Setup, Prepare, Capture and Review.
For each phase there is a set of typical tasks the completion of which requires actions.

The camera has user interface modules (UIM) which allow the user to perform those actions.

Prepare Phase  is that period of a few minutes prior to taking photos when the user configures the camera for the present circumstances.

Capture Phase  is when the user is in the process of taking photos.
The table below lists typical tasks likely to be required in each phase. Some tasks could be regarded as part of either phase, depending on circumstances.

Prepare Phase
Either
Capture Phase
Exposure Mode: Auto, P, A, S, M
P, A, S, M
ISO
Primary exposure parameters
ISO, FStop, Shutter Speed
Other Modes: Focus, Autofocus, Drive, Flash, Metering, Silent.

Secondary exposure parameters
Exposure compensation [+/-]
White balance
AE Lock
Program shift
Settings: Quality, Size, Shutter type, Stabiliser, Burst, Aspect ratio, Macro.

Primary focus parameters
Start/continue AF
Set MF
Displays: E-Level, Info, Histogram,


Secondary focus parameters
Set position and size of AF/MF box
AF Lock
AF in MF, MF in AF
Motion Picture settings

Zoom

Of course, most photos will require change to only a small number of these parameters but the capability to change any of them needs to be built into the user interface.

The user of a modern camera could be very busy in both phases if  all the available features and functions of a modern camera are fully utilised.

It behoves the designer therefore to optimise the design of UIMs for efficient operation in both phases.

Prepare Phase actions are typically carried out with the camera held  away from the face so the top and rear aspects of the device are visible and accessible to the fingers.

Capture Phase actions are optimally carried out while looking through the viewfinder. UIMs are operated by feel without disrupting grip with either hand.

Optimal UIM types:

For Prepare Phase: include set and see modules (often rings or dials), Programmable Function Buttons and a user selectable Quick access mini menu.

For Capture Phase: include Control Dials, Rocker Modules and  rings. The function of modules for Capture Phase is determined by context.  For instance in Aperture Priority Mode a control dial changes aperture. In Shutter Priority Mode the same dial controls shutter speed. Optimally the dial always turns the same way for “value up” and the opposite way for “value down”.

Set and see modules are not optimum for Capture Phase as the camera has to be taken down from the eye to see them, disrupting the flow of picture taking. Of course the data generated by set and see modules is usually replicated in the viewfinder (and monitor). But the opportunity cost of this is a duplicated interface.

A set and seemodule allocated to a Capture Phase task could have been more efficiently used for  Prepare Phase. 

The LX100 has three set and see  modules allocated to Capture Phase tasks. These are the Aperture Ring, Shutter Speed Dial and Exposure Compensation Dial.

Many reviewers and users have written positively about this arrangement. I am not one of them. In this series of posts about the LX100 controls I present a dissenting view.

This will continue in the next post of the series in which I will summarise some findings from my time and motion studies of camera operation.  



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