The Curious Case of Samsung i-Function

Background   In January 2010, Samsung introduced the company's first compact system camera, the NX10.  I used the NX10, then a mild upgrade, the NX11,  for the next two years. It is a decent little camera with a user friendly human machine interface (HMI).  However the NX10/11 needed an upgrade to  image quality, performance and  EVF  to keep up with it's CSC competitors. Instead, it got Samsung i-Function.

What is it ?      i-Function is activated by pressing a button on the barrel of the lens.  This brings up a unique interactive window on the monitor or EVF.   This consists of a broad ribbon of data across the lower quarter of the frame, completely obscuring the standard  display of shutter speed, aperture and exposure compensation status beneath the image area.  The button may have to be pressed up to 5 times to scroll between functions available. When the desired function has been reached, adjustments are made by turning the focus ring on the lens. A half press on the shutter button confirms the setting and returns the camera to normal shooting mode.

What can it do ?   On the NX11, i-Fn can alter several Capture Phase parameters. These are the  primary exposure variables (ISO, Shutter Speed, Aperture) and  the secondary exposure variables Exposure Compensation and White Balance. Selection of Scene Modes, a Prepare Phase function, can also be allocated to i-Fn. 

Note that Samsung cameras with i-Function allow all these imaging parameters to be adjusted in traditional digital camera fashion, using the buttons on the top and rear of the body together with the mode dependent scroll wheel behind the shutter release button. On my NX11, i-Fn cannot be completely disabled although the ability to adjust ISO and White Balance by i-Fn can switched off  via the main menu.

User and reviewer response  Some users reported negative reactions to i-Fn, others said they really liked it. Several reviewers reported positively about i-Fn. I have not seen a published systematic ergonomic analysis of  i-Fn, so here it is.

Principles of Lens Based User Interface Modules (UIM)   Buttons and levers on the barrel of a lens are appropriate for Prepare Phase adjustments when the user is not taking photos. The camera can be held in one hand while the other hand operates buttons and levers on the lens barrel after locating them visually. Typical parameters for adjustment this way would  include Focus Limiter, AF/MF, Stabiliser O/I and Stabiliser Mode. Buttons and levers are difficult to locate by feel and become impossible to find when the camera is rotated to  portrait (vertical) orientation. Some users prefer underhand, others overhand grip on the lens.  Buttons which might be reasonably accessible with one of these grips become difficult to locate with the other.

If lens based adjustments are required in Capture Phase the UIM's  must be located by feel.  In this case,  circumferential collars or rings work best.   If these have an appropriately tactile surface profile, they  can be operated by the fingers of the left hand in landscape or portrait orientation, using "hand under" or "hand over" grip. Typical Capture Phase tasks allocated to lens based modules include manual focus and zoom.

First, here is the sequence of actions required to adjust Aperture using the Scroll Wheel.  Neither the right or left hand is required to shift grip or move in any way during this brief action sequence.

1. Move the right index finger 13 mm back from the shutter  release button to engage with the Scroll Wheel.

2. Turn the Scroll Wheel while watching Aperture and Shutter Speed readouts in the data strip below the image.

3. Return index finger to shutter release button and press to capture.

Now here is the sequence required to adjust Aperture using i-Function.

1. Release the left hand from normal operating position, search by feel for the i-Fn button with the left thumb. Note  this button is much more difficult to find in Portrait orientation and requires an awkward position of the left hand.

2. Press the i-Fn button 1-5 times depending on the number of functions allocated to i-Fn and the order in which they appear on the information ribbon.

3. Move the left hand again (some lenses require more movement than others) until the focus ring is located by feel.

4. Move the focus ring while observing the readings on the data ribbon. Note that when changing any parameter by i-Fn the standard data display of Aperture, Shutter Speed and Exposure Compensation status, is obscured, preventing observation of the effect of changing one parameter on the others. Note also the i-Fn display presents a completely different cognitive experience (the appearance of a horizontally moving ribbon) to the standard data readout (Aperture and Shutter Speed readouts stay in one place, changing in value, with a coloured background indicating the currently active parameter).   Either arrangement works but switching back and forth between the two is disorienting.

5. Half press the shutter release button to confirm the setting and return to normal operating mode.

Summary of action analysis  I could describe the steps required to alter each of the variable parameters able to be changed using i-Function, but there is little to be gained by so doing. The process is very similar for each. Adjustment of ISO and WB the standard way  requires a button press before rotating the Scroll Wheel.

Conclusion  In every case, when compared to the standard operating method, adjusting a parameter with i-Function takes longer, requires more steps, requires more finger movements and obscures camera status data during the process.

All of which leads to the obvious question:  What was Samsung trying to achieve with i-Function ? As a consumer, I have no idea what Samsung's product development team were thinking.  However perhaps we can get a clue from the way i-Function is used in Samsung's promotional and marketing material.

These quotes from Samsung website material on 1 June 2012 are representative:  "Touch one button.  Change everything".  "The i-Function lens just made conventional cameras obsolete".  "One step control of Shutter Speed (Aperture, WB ...etc)".

Clearly the marketing people want you to believe that i-Function is a wonderful new thing which somehow changes everything and makes conventional cameras obsolete.

One of the claims made for i-Fn is incorrect as to fact.  That is the "One Step Control" claim. I suppose one could have a futile debate about the precise definition of a "Step", but on my evaluation the minimum required for an i-Fn adjustment is 3 steps, with several requiring more.

My guess is that Samsung marketing wanted a unique selling proposition (USP) for the NX series and somehow came up with the i-Function idea.  Unique it may be and selling point it may be but when subjected to ergonomic analysis it becomes very clear that if the camera is used for the purpose of making photographs (as opposed to just experimenting with the controls) then  i-Fn adds nothing useful to the user experience.

Photo 1, Prepare Phase UIM's   This shows a set of  switches on the barrel of a lens. They operate functions required in the Prepare Phase of use. Zoom and Focus in the Capture Phase are operated by wide circumferential rings. This lens is a good example of optimal UIM design and location.

Photo 2, Standard Display This shows the well designed, easy to read, standard  Samsung data display. Here Aperture is showing as active. When altered the effect on Shutter Speed is immediately apparent.

Photo 3, i-Fn data display  This obscures the standard display and prevents the operator from monitoring Shutter Speed while Aperture is changed. In addition it presents a cognitive experience which is completely different from the standard display and a distraction from the process of making photographs.

Photos 4 A-C  This sequence of three photos shows the process of using i-Fn with the 50-200 mm lens.  4A shows the left hand in standard "Hand Under" position.  4B shows that in order to activate i-Fn the left thumb has to move back 40 mm to find the I-Fn button. The button has a low vertical profile to prevent accidental activation but this makes it difficult to locate by feel.  4C shows that in order to change a setting the left hand must now move forward 65 mm to reach the focus ring.

I actually prefer the "Hand Over" grip with this lens which makes using i-Function almost impossible.

Photo 4 D Shows the camera in portrait orientation with the i-Fn button out of sight, difficult to reach with any finger and therefore almost impossible to use.