M43 Super Wide Angle Zoom Lens Comparison

Panasonic 7-14 mm vs Olympus 9-18 mm Using Panasonic GH2 and Olympus EM5

Author AndrewS  August 2012

Left to right: Panasonic 14-45mm, Panasonic 7-14mm, Olympus 9-18mm, Olympus 12-50mm.

Introduction  The Micro Four Thirds system is growing strongly partly due to the number and quality of lenses available. Panasonic and Olympus have taken a quite different approach to the design brief  for a super wide angle zoom leading to an interesting comparison.  My experience over many years has been that standard test procedures using charts in controlled conditions only tell half the story about lens performance.  So I bought both lenses and both the GH2 and EM5  camera bodies for comparison and testing over a period of two months and many hundreds of photographs in a wide variety of conditions, including test charts and real world situations. 

On the left Olympus EM5 with 9-18mm extended for use. On the right Panasonic GH2 with 7-14mm.

Panasonic-Olympus lens-body compatibility  My understanding of the M43 concept is that in principle all lenses conforming to the standard would be compatible and work properly on all bodies. However in practice this is not entirely the case. To help myself understand this matter more clearly I have somewhat arbitrarily defined three levels of lens/body compatibility:

Level 1 covers the primary exposure parameters of ISO, Shutter Speed and Lens Aperture. This level also includes autofocus performance and reliability.

Level 2 deals with in camera correction of chromatic aberration and possibly other aberrations, corner shading correction and distortion correction. Panasonic cameras correct distortion and CA but not necessarily shading in RAW and JPG files but only with Panasonic lenses. Olympus cameras do not correct CA with either Olympus or Panasonic lenses. They may correct distortion to some extent with some lenses.

Level 3 includes a range of issues such as banding with certain body/lens combinations, electronic lockups and any other unexpected faults, failures or performance issues resulting from mixing maufacturers.

My testing has shown that lens-body compatibility issues are a major factor in the overall performance and functional reliability of each lens. Compatibility issues can, and in my experience do, occur at each of the three levels.

Treillage, Panasonic 7-14mm on GH2

Note on sample variation  My experience and reading indicates significant sample variation in both lenses and bodies. The findings reported here are valid for the particular samples which landed in my posession and may not be replicated exactly with other samples. However both lenses and bodies tested appear to be good with no obvious faults or defects. The only issue I noted is slight decentering of the Olympus 9-18mm lens as evidenced by slightly more softness in the top corners than the bottom corners  in landscape orientation at the wide end.

Design philosophy  You can see at a glance that the Panasonic and Olympus designers have taken a completely different approach to the SWA lens concept. The Panasonic goes for the highest possible optical performance while the Olympus achieves an astoundingly compact form. I think both succeed rather brilliantly but their success lies in different aspects of the performance spectrum so they are somewhat difficult to compare directly.

Strand Arcade Sydney Olympus EM5 with Panasonic 7-14mm

Specifications  You can read all the details elsewhere but in summary the main points are:

Zoom Range:  Both are 2x zooms but they have a different focal  length range. If you have not used a SWA lens before, you might not think there would be much difference between 7 and 9 mm at the wide end, but in practice the difference is very noticeable indeed, moving the Panasonic 7-14mm lens into Ultra Wide Angle territory, capable of extreme perspectives and requiring considerable care with composition. The other thing to bear in mind is that the 9-18mm range of the Olympus overlaps quite a bit with standard 12-50mm and 14-42mm zooms.

Collapsing Design:  The Olympus collapses from 71mm long in operating configuration to 49mm for storage. The Panasonic is 83mm long including the fixed petal hood.

Nominal Cylinder Volume: This is length x Pi x (half max diameter) squared, approximately representing the space which the lens will require in a camera bag. With front and rear caps in place the Panasonic measures 9.3 x 7.2 cm giving a Nominal Cylinder Volume of  380cc. The Olympus, again with front and rear caps in place and in collapsed configuration is 6.2 x 5.5 cm for a volume of 147cc. So the  Olympus nominal volume is 38%  of the Panasonic.  The Panasonic is by no means a big lens, indeed it is diminutive compared to SWA lenses for APS-C and Full Frame sensors.  But the Olympus is even smaller when collapsed, a remarkable feat of optical engineering. It can be tucked into an otherwise unused corner of a camera bag or nestled below or on top of another lens, taking up very little space.

Filter: With it's large dome shaped front element partly protected by a built in petal shaped lens hood, the Panasonic cannot accept a filter. I would think carefully about exposing this lens to salt spray or heavy dust. The Olympus somehow manages to enable a standard 52mm filter to be fitted, it doesn't even need an ultra slim type.

Mechanical operation  Both lenses zoom smoothly and feel well made. Both change length with zooming but on the Pansonic this occurs inside the fixed lens hood. Presumably the Panasonic/Olympus coordination committee was having a picnic day when someone designed the zoom action because they turn the opposite way !!! When mixing and matching between Olympus and Panasonic lenses I constantly find myself zooming the wrong way as a result.

The collapsing function on the Olympus is easy and smooth to operate, with a lock button.

Autofocus Performance and Reliability  I made several hundred photos using a wide variety of subjects and lighting conditions, using each lens on each camera. I kept notes along the way. In summary the rate of focus error was lowest with brand matched lens/body pairing. The Pana 7-14 on EM5 was quite prone to focus errors, especially in conditions with low light level and/or low subject brightness range. Sometimes the camera signalled difficulty finding focus but at other times it indicated focus acquired when that was not the case. Subjects with numerous glowing light sources in frame were a particular problem. This appears to be an issue for contrast detect AF systems as I have encountered it with the Samsung NX10/11 which usually have highly reliable AF, and seen the issue reported with Sony NEX cameras. The photograph of Strand Arcade made with the Pana 7-14 on EM5 produced several misfocussed frames.

Manual Focus  (No focus by scale)  No problems were experienced with manual focus using AF+MF or MF, both with MF assist. My ongoing complaint with M43 and all mirrorless ILC's to date is they lack any kind of facility for manually setting a chosen distance by scale. I don't understand why this is not provided as an on screen readout since the camera presumably "knows" what is the focussed distance set by the lens at any time. If this facility were available I would use it almost all the time with Wide and Superwide angle lenses which are ideally suited to prefocussing at the hyperfocal distance.  

Olympus 9-18mm on EM5 100% crop from corner

Optical Performance

Resolution: Both lenses deliver very high resolution in the central image area, with little discernible difference between them at any comparable focal length or aperture. In the central area virtually maximum resolution is delivered at the widest aperture available. The story is different at the edges and even more so in the corners. Here the Pana 7-14 shows clearly better resolution at all apertures and focal lengths. Stopping down provides slight benefit for the Oly 9-18 but makes little discernible difference with the Pana 7-14.

Panasonic 7-14mm on GH2 100% crop from corner

Contrast: The Pana 7-14 holds local contrast well, right into the corners, but the Oly 9-18 suffers from loss of contrast towards the corners.

Flare, General, Local, purple: As with most super wide lenses, direct sun on the front element of either lens will produce a variety of unwelcome flare patterns. The Oly 9-18 is prone to local flare towards the corners particularly with subjects having a high brightness range. In these conditions there is considerable local image degradation due to light flaring from bright subject areas into dark areas. The Pana7-14 is subject to a curious phenomenon which I have only encountered on the EM5 thus far. This is one or more large areas of soft  purple flaring in the vicinity of bright light sources in the frame. This has been reported on the dpreview m43 user forum. I am not aware of a cure for this problem.

Chromatic Aberration: This is clearly present toward the corners with both lenses. It is corrected in camera with the Pana7-14 on Panasonic cameras but not corrected in the other lens/body combinations. It can easily be eliminated in ACR 7.1 or LR4.1.

Purple Fringing: This can be very prominent towards the corners with both lenses and is corrected in camera, sometimes incompletely depending on the subject, with the Pana7-14 on Panasonic camera. Purple fringing can generally be eliminated or at least greatly reduced by judicious use of the control sliders in ACR7.1 or LR4.1.  

Drawing (geometric distortion): The Pana 7-14  on Panasonic cameras produces partly corrected barrel distortion at the wide end and incompletely corrected pincushion distortion at the long end. The Oly 9-18 on EM5 shows more obvious barrel distortion at the wide end and just the slightest trace of barrel distortion at the long end.  In each case the distortion pattern is evenly circular (not moustache type) and easily corrected in ACR 7.1 or LR 4.1.

Optical Performance Summary  In a broad central area of the frame both deliver excellent performance, with little to choose between them. Towards the edges and corners the Pana 7-14 has a clear advantage. So overall the Panasonic has the best optical performance and is a stop faster at the long end as well. The actual level of resolution achievable by both lenses is extremely high, enabling images containg a remarkable amount of fine detail.

Conclusion: Two lenses, Two winners  Each of these lenses has clearly been designed to optimise a different range of characteristics and capabilities and each succeeds resoundingly. Your buying decision will depend on which are most important for your own requirements.

What Shall We Call Them ?

WHAT SHALL WE CALL THEM ?

An opinion piece on naming camera types

Author  AndrewS    August 2012

Introduction    On 12 September 2008, Panasonic announced the Lumix G1.  This was the first model of a new type of camera which allowed interchangeable lenses but eliminated the reflex mirror, prism and optical viwefinder of a DSLR.

Ideal Design ILC Mockup

As I write this there have been 49 cameras of this type released or announced with all the major camera makers having one or more models.

Despite this major investment and product rollout, there has been no general agreement as to what these new style cameras should be called.

Brief history of camera types and names  In the early days of photography a camera was a large device supported by a solid tripod. The operator put a dark cloth over his (it was mosly his, the ladies presumably having more sensible things to do)  head and directly viewed a left/right, up/down inverted image of the subject on a ground glass screen. Hence the name "View Camera". Photography was democratised with Kodak's invention of the "Box Camera" thus named for obvious reasons. In due course Leica invented the "Miniature" camera which used perforated 35mm movie film. In due course the Leica acquired a "messsucher" or rangefinder and the Rangefinder Camera was born. Then came the Twin Lens Reflex  (TLR) type where you viewed the subject through one lens and exposed film with a second lens. The word "reflex" referred to the angled mirror located in the optical path of the viewing lens.  Then came the Single Lens Reflex  (SLR) camera in which a flipping mirror enabled viewing and image capture through a single, interchangeable lens. In the film era there were many small cameras with a fixed lens usually referred to as "Compact".

In the digital era we still have compact cameras in abundant numbers. Some of these have a long zoom lens and are referred to as "Travel Zoom". Some go one step further by adding an electronic fiewfinder and an even longer zoom, hence the name "Superzoom".

The SLR has become a Digital SLR (DSLR) and Leica still makes it's Messsucherkamera (M type), albeit with a digital sensor.

The new camera type  So now we come to the new camera type, and review some of the names it has been called, in no particular order.

EVIL  Electronic Viewfinder  Interchangeable Lens:  Apart from the obvious problem that no maker is going to refer to it's product as "evil" most of these cameras do not have an electronic viewfinder, at least not one you can put to the eye. 

MILC  Mirrorless Interchangeable Lens Camera:  This terminology is frequently used by dpreview.com  but written out in full and not abbreviated to MILC.  Maybe they think the image of "Milk" does not fit well with an electronic device. The name seeks to describe a device by reference to a feature which it does not posess, namely a reflex mirror. This has probably been useful in the early days of the new type, to distinguish it from the DSLR which was the dominant interchangeable lens camera type in 2008 and still is in 2012, but that is changing.   I see two problems with this name as time goes on and the electronic camera market matures.  First, cameras which do have a reflex mirror are already identified (TLR, SLR, DSLR , SLT) so it is redundant to keep on referring to those without a mirror as "Mirrorless". Nobody today refers to the motor vehicle as  "Horseless".  Second, I believe (and if their new product rollout is any guide, so do the camera makers) that in a few years the interchangeable lens camera domain will be dominated numerically by mirrorless devices, which will become the new standard configuration for consumer level cameras.

CSC  Compact System Camera:  The Technical Image Press Association (TIPA) has been promoting this name with some success and Canon has described it's new EOS-M camera as a CSC.  However there are difficulties with the CSC name. First, the term "compact" is already in general use to describe cameras with a fixed, non interchangeable lens. Second, "compactness" is an undefinable concept dependent on individual expectations about camera size. Third, the size of the new style camera is a consequential  benefit (or curse, if you don't like very small cameras) of the technology inside the camera, not a fundamental attribute of the concept.  Fourth, the idea of  a camera "system" is also undefined and subject to differing interpretation.

MSC  Mirrorless System Camera:  The New York photo vendor B&H uses this terminology, presumably for practical reasons as it helps customers find their way through the extensive catalogue on offer.  I can see how this makes sense for the time being but in the longer run MSC has the same problems as MILC and CSC.

DSLM   Digital Single Lens Mirrorless:  Panasonic has started promoting this name with the introduction of it's Lumix G5 camera in August 2012. To my mind it is the least useful name which I have yet encountered.  In a world where 98% (I don't know the exact percentage) of cameras are digital it is pointless referring to this attribute. The "Single Lens" designation was invented over 50 years ago to distinguish the SLR from the TLR, a pointless reference given the absence of TLR's in today's  market. My objections to the term "mirrorless" have already been made.

So what name is best ?   I think that right now now and anticipating the evolution of camera types, the name which makes most sense to me is, simply, Interchangeable Lens Camera.  (ILC).

This acknowleges that there are two main camera types, those with fixed lenses and those with interchangeable lenses. It anticipates continued  growth of "mirrorless" types as a percentage of the interchangeable lens category. It incorporates the value of looking forward rather than backwards. It acknowleges that cameras with some type of reflex mirror are already clearly identified.   It does not burden the name with redundant, outdated  or unecessary descriptors.

Footnote  I was looking at the Panasonic USA website recently and noted that Panasonic appears to be having a three way bet on the naming question. As the company was in the process of promoting the DSLM name in Europe, the USA website listed  Lumix G cameras as both Compact System Cameras (CSC) and also Interchangeable Lens Cameras (ILC).

Appendix: ILC's released or announced as at 10 August 2012

In alphabetical order:

Canon EOS-M; Fuji X-Pro 1; Leica M8, M9 and variants; NikonJ1, J2, V1; Olympus EP1, EP2, EP3, EPL1, EPL2, EPL3, EPM1, OMD-EM5; PanasonicG1, G2, G3, G10, G5, GH1, GH2, GF1, GF2, GF3, GF5, GX1; Pentax Q, K-01; RicohGXR with 5 lensor units and one lens mount module; Samsung NX 10, 5, 11, 20, 200, 210, 1000; Sony NEX  3, C3, F3, 5, 5N, 7.

Canon EOS 60D Ergonomic Review

CAMERA ERGONOMICS

Ergonomic evaluation of the Canon EOS 60D

Not bad but not excellent

Author  AndrewS  June 2012

Introduction   For many years my cameras of choice were Pentax SLR's starting with the Spotmatic.  But Pentax was slow to embrace autofocus so in 1989 I switched to Canon EOS, starting with the 630.  That was followed by the 10, 50E, 1V  and 33V.  In the digital era, I have owned and used the 20D, 40D, 450D  and currently the 60D with a range of zoom lenses.

Photo 1

User level  Looking at it's price point, specifications and features I rate the 60D as a camera intended for use by photographers at  Level 4 (Expert/Controller, frequent use).  This is not an entry level/snapshooter camera.  Photo 1 shows the 60D basic hold.

Image Quality and Performance   This is an ergonomic review but I will make brief reference to the other two pillars of camera evaluation. Image quality has been exhaustively analysed elsewhere. Suffice to say it is good enough for almost any photographic project. Performance is also very good in all respects except autofocus accuracy. I find that particularly at the wide end of zoom lenses, AF is erratic, sometimes focussing incorrectly even in good light.  I have experienced this problem to some degree with every Canon EOS camera which I have owned.

Ergonomics   There are four phases of camera use, Setup, Prepare, Capture and Review.

Setup Phasemostly involves selection of menu options. The 60D menus are well laid out and easy to navigate. Submenu options never occupy more than one screen so scrolling down  in search of an option is not required. My Menu takes user allocated options for quick access. This is a much better arrangement than some other cameras which automatically shift recently used items to the My Menu screen. Compared to some other cameras, the 60D's menus are a model of clarity.

Prepare Phase  AF Mode, Drive Mode and Metering Mode are adjusted by the Press Button>Scroll Wheel>View LCD Panel method.   This gets the job done but Set and See Dials/Levers use fewer actions and can be set without having to switch the camera on. Other parameters are adjusted via the Q Menu. This also gets the job done but a more streamlined interface would be possible if each item in the Q Menu could be user set.

Capture Phase       The three main descriptors of ergonomics in this Phase are Holding, Viewing and Operating.

Holding  The 60D is a nice camera to hold. It is a good size for average adult human hands. It has a well shaped handle and thumb rest. It conforms to the hand much better than many smaller DSLR's and Compact System Cameras.

Viewing  Both the eye level viewfinder and the monitor screen are clear and bright, giving an excellent view of the subject. Camera status indicators are clearly visible in either viewing mode. The only downside of the viewing arrangements on this camera are those inherent in the DSLR concept, namely that eye level viewing and monitor (Live) viewing are separate user interfaces with a different AF system and different presentation of camera status data. This arrangement is not bad. However mirrorless (or Sony SLT) cameras offer a seamless segue from eye level to monitor viewing.

Operating  For the Level 4 photographer who wants to take control of camera functions in the Capture Phase, there is a substantial task list to be completed in a few seconds. The specific items on the list will vary somewhat with individual preference, but deliberative practice will typically include the following:

* Hold camera steady with both hands, without changing grip.

* View subject in the viewfinder without interruption, compose, zoom.

* Shift active AF area if required,  or center focus and recompose, or AE + AEL, or AF + AFL.

* Adjust Aperture in A Mode, or Shutter Speed in S Mode, or Program Shift in P mode, or Aperture + Shutter Speed in M Mode.

* Adjust ISO.

* Adjust Exposure Compensation if required.

* AF or MF > AE > Capture.

Let us analyse how the 60D goes about completing this task list.

The left hand is busy supporting the mass of the lens plus zooming and manual focussing if required.

The right thumb has to play an important part in gripping the camera but also has carriage of three Capture Phase tasks.

1. Start/lock AF with the AF-ON button. This button is just about perfectly placed on the 60D, making back button AF start/lock a smooth operation.  I would prefer the button to be slightly more prominent to make it easier to operate without having to flex the interphalangeal joint, but it works well enough as is.

2. Shift active AF area. This task is allocated to the 8 Way Controller. To engage with the 8 Way Controller the thumb has to drop down 50 mm from base hold position. In order to do this  the right hand has to release it's grip on the camera, forcing the left hand to take the full mass of the camera and disrupting the Capture Phase work flow.  It is also difficult to reliably hit the exact spot on the controller required to select intermediate AF sensor positions.

Photo 2

3. Exposure Compensation is allocated to the rear/lower scroll wheel, access to which requires the same actions as described above.

These arrangements for shifting active AF area and Exposure Compensation get the job done. Ergonomically the process is not bad but it could be upgraded to excellent with some minor changes to the user interface.

This camera has plenty of space for a JOG Lever, the optimum location for which is indicated by the white X in Photo 2.  The existing buttons would have to be slightly relocated.   The thumb has only to move 12 mm to the left, by side to side movement at the carpo metacarpal joint to engage with and operate the JOG Lever. This is the ideal user interface for shifting active AF point. The JOG Lever can also make itself useful for scrolling around items in Setup, Prepare and Review Phases of use.

Exposure Compensation can be moved up to the index finger's operational zone, as described below.

Photo 3

Now let us examine the role of the right index finger in Capture Phase.     On the 60D  the index finger operates the Shutter Release Button, the Mode Dependent Scroll Wheel and the ISO button.  The layout is shown in Photo 3.   But there are several ergonomic problems with this arrangement.

* The horizontal distance from the center of the Shutter Release Button to the center of the ISO button is 27 mm. This is a stretch too far for many people whose metacarpo phalangeal joint may have just average flexibility for side to side movement.

* ISO is a Primary Exposure Parameter, which should be easily adjustable in the Capture Phase of use. But the ISO button is in the middle of a row of identically shaped (apart from a tiny little nipple on the ISO button) and sized buttons, the other three of which are allocated to Prepare Phase actions.

Photo 4

* The consequence of these arrangements is that when using this camera I cannot reliably find  the ISO button by touch. My hands are 69 years old, like the rest of me, but they are in good working order, free from arthritis and degenerative disorders. If I can't do it, there will be plenty of other people in the same situation. As a result adjusting ISO goes back to being a Prepare Phase action, requiring the camera to be lowered from the eye and the ISO button located by sight. This is not the end of the world, it just means that the process of making photos has to be interrupted to change ISO. Ergonomically, it's not bad but not optimal either.

This camera has plenty of space to fit a much more efficient layout of User Interface Modules for use by the right index finger. One option is the Quad Module system which could be implemented in any of several different ways, but one which fits the projecting handle design of the 60D is shown in Photo 4.  This system allows the index finger to rapidly control the primary exposure parameters (Aperture, Shutter Speed, ISO), the secondary exposure parameter (Exposure Compensation), AF if desired, AE and Capture, all with minimal physical movement, without disrupting view or grip. There is a division of labour between the thumb and index finger with the  thumb having control of AF if desired and focus area position.

Photo 5

I like to use the sports car analogy when thinking about camera ergonomics. For optimum speed and accuracy of operation without the driver having to think about each separate action, the accelerator, brake and clutch pedals have to be at the same height and close to each other, but not too close.

The UIM's in Photo 4  are placed with a similar concept in mind. They are at the same height so the finger can move directly from one to the other and they are close, but not too close. I spent a lot of time relocating UIM's on mockups to arrive at the disposition shown here. The horizontal distance from the center of the Shutter Release Button to the center of either the ISO or EV Buttons is 21 mm, an easy reach for most people. These two buttons  have a different shape and feel so they are easily located by touch. In a working camera their functions should be user selectable from a wide range of options.  There are plenty of photographers who would want to use these buttons for different purposes.

Photo 5  shows another version of the Quad Module system on a Sony camera. In this case we see a good  idea poorly executed, with excessive distance between the Scroll Wheel and the other Modules which are also at a different height and in a different plane.

Photo 6

Photo 6  shows another version of the Quad Module system on a mockup with Parallel Handle,  with the UIM's laid out in a fashion which suits the handle design.

Summary  I have been using Canon's mid range SLR's and DSLR's for many years. Apart from chronic autofocus accuracy problems they have all functioned reasonably well. The thing which I am not seeing is evolving improvements to the user interface, in other words, ergonomics. There are changes, the monitors grow and acquire swivel. The buttons move around, mostly to allow the larger monitors. But the process of controlling the camera in Capture Mode has not improved.   In fact, in some respects such as the loss of the JOG lever, it has gone backwards.

If Canon revised the user interface of the 60D in the ways which I have suggested the experience of operating this camera could  improve from "Not Bad" to "Excellent". There would be no cost penalty. Good ergonomics costs no more than poor ergonomics. Poorly located UIM's cost just as much as well located ones.

The Curious Case of Samsung i-Function

CAMERA ERGONOMICS

The Curious Case of Samsung  i-Function

If  i-Function is the answer, what was the question ?

Author AndrewS  June 2012

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.

Photo 1, Prepare Phase UIM's

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.

Photo 2 Standard Data Display

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.

Ergonomic analysis of one task, i-Fn versus Scroll Wheel

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.

Photo 3, i-Fn Data Display

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.

Photo 4A Normal Hold

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.

Photo 4B Thumb on i-Fn

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)".

Photo 4C Rotate Focus Ring

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.

Photo 4D Vertical hold

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.

Photographs

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.  

 

Ergonomic Analysis of Mode Dependent Scroll Wheels

CAMERA ERGONOMICS

AN ERGONOMIC ANALYSIS OF

MODE DEPENDENT SCROLL WHEELS  [MDSW]

Author  AndrewS  May 2012

Introduction  I have spent substantial time over the last two years making camera mockups with the aim of improving the ergonomics of  hand held cameras. One strategy I have used is to explore options for the position and design of User Interface Modules (UIM).  I do this by physically moving buttons and dials to different places on the mockup. This article deals with the Mode Dependent Scroll Wheel.

Definition   There are two main types of control wheels or dials commonly found on cameras.  One is the "Set and See" type. Set and See levers are also popular, often incorporated into a dial type control module. Set and See dials have a single function at each set point although some cameras allow user configuration of the details.

Photo 1 Optimum MDSW Layout

A Mode Dependent Scroll Wheel [MDSW]  has no markings. It's function is dependent on the current operating mode.  It is particularly well suited to Capture Phase tasks.  Thus in Aperture Priority Mode the Scroll Wheel will change Aperture. In Shutter Priority Mode it will change Shutter Speed.

Rationale of the MDSW   Modern electronic cameras suitable for Level 3 users  (Expert/Controller, occasional use) or Level 4 (Expert/Controller, frequent use)  users, are very complex, requiring the operator to make many adjustments very quickly. In the Capture Phase, these adjustments need to occur while the operator is holding the camera firmly with both hands and looking at the subject through the viewfinder. The mode Dependent Scroll Wheel can, if optimally positioned and designed, meet the requirements of that situation.

Photo 2, Good MDSW Location

Job Description for a MDSW  In the Capture Phase, a well designed and located Scroll Wheel should be able, if optimally supported by other User Interface Modules (UIM's) to  adjust Aperture, Shutter Speed, ISO, Program Shift and Exposure Compensation. In addition it provides  scrolling functions in Setup, Prepare and Review Phases. It should not be prone to unintended activation. It should be easily located and operated by feel, while the user is framing the subject with the eye level viewfinder. It must be fully operational without the user having to shift grip on the camera with either hand.

Current Practice  A review of current camera designs shows that some cameras have none, some have one, others two. Some cameras have three. There is no agreement about location. Some cameras have them on the top plate. Some of those rotate on a horizontal axis others on a vertical axis. Some are on the back but there is no common practice as to where precisely they should be located on the back. Some cameras put a Scroll Wheel on the front.

Compare this to the location and operation of shutter release buttons on cameras about which there does appear to be substantial consensus.

Scroll Wheels are in a state of design flux, with no agreement about the optimum number, position or function having yet been reached.

By way of further comparison we can consider the motor car.  Convergent evolution in cars has reached the point where  the main controls are located in the same place and operate the same way in all makes and models.

Photo 3, Poor Front Location

The same kind of convergent evolution has not yet occurred in cameras.

Functional Anatomy of the Human Hand  Camera design is subject to multiple interpretations but the hands which use those cameras do not change at all. They have had the same morphological and functional anatomy for many thousands of years.  I have discussed this in detail in my article "Functional Anatomy of the Hand" on this blog in March 2012.

Briefly, the right index finger is the only digit which has no "gripper" role. It only has "controller" functions. It is the only digit which can operate UIM's  (provided they are correctly designed and positioned)  without affecting the user's grip on the camera.

The Problem with Likes and Preferences  It might be thought that a useful way to discover the optimum arrangement of Scroll Wheels would be to ask camera owners about their likes and preferences. But there are serious problems with this approach. Likes and preferences are idiosyncratic, transient and sometimes unformulated.   They can only arise out of prior experience and as such may give no useful guide to the way forward. The conclusions reached from that experience may be misconstrued.

Photo 4, Difficult Rear Location

Here is an example from personal experience.  I bought and used a Pansonic G1 with a Scroll Wheel located upper front on the handle.  This was unsatisfactory as the right middle finger lay right across the Control Wheel in normal holding position. So, in order to operate the wheel I had to release the camera with  my right hand to allow access to the wheel with my index finger. Thus I could not hold and operate the camera at the same time. Subsequently I bought a Panasonic GH2. This camera has the Scroll Wheel located on the back, upper right where it is operated by the thumb. The GH2 wheel is easier to reach and operate. I might have concluded  incorrectly from this experience that rear/thumb operated Scroll Wheels are "better" than front/index finger operated ones.  However a full ergonomic task, time and motion analysis revealed that although one is easier to use than the other, neither solution is optimal. The way forward lies in a direction different from either of these arrangements.

Another example: I sometimes read on user forums the idea that a camera operator would "like" or "prefer"  to have his or her right index finger resting on the shutter release button "ready-to-make-the-exposure" while the right thumb makes adjustments using various UIM's.  A task, time and motion study shows that typical adjustments in the Capture Phase (AF Area position, Exposure Compensation ISO, Aperture, etc) are made sequentially prior to shutter release. The actions do not occur simultaneously. If these tasks are allocated to the thumb then a better ergonomic description of the index finger's role in the process would be "Sitting-idly-doing-nothing-when-it-could-have-been-adjusting-exposure-parameters".

Photo 5, Poor Rear Location

My point is that user's likes and preferences do not reliably lead us to optimal ergonomic solutions to problems at the Human Machine Interface (HMI).

Analysis of Scroll wheel  locations

1. Rear of camera, thumb operated.  Many cameras have these and they get the job done  in most cases. However if the Scroll Wheel is located directly under the ball of the thumb in basic hold position it will be constantly at risk of accidental activation. If  it  is located to the left , right or below the ball of the thumb in rest position then the user must shift grip with the right hand in order to operate the Wheel. The amount of shift may not be great but it still adds two steps to the process which is suboptimal.

2. Front of camera, below the level of the Shutter Release Button.  The worst of these require the right hand to shift downwards in order to allow the right index finger access to the Wheel. Better ones allow the grip to remain but require the index finger to move a substantial distance to reach the Wheel. 

Best Practice Derived from Ergonomic Study and Mockups  An analysis of task, time and motion shows that the best place for a Scroll Wheel is close to, on the same level as and just in front of or behind the shutter release button.  If optimally designed this location meets all the requirements of the job description.

My experiments indicate the  optimum distance between the center of the shutter button and the center of the Scroll Wheel is 13 mm.  The best ergonomic result is given by a cluster of four UIM's all operated by the right index finger. These are Shutter Release Button, Mode Dependent Scroll Wheel, ISO button and Exposure Compensation button. Both these buttons should permit user selectable function from a substantial list of options.

The optimum distance betweeen the center of the Shutter Release Button or Scroll Wheel and the Exposure Compensation or ISO buttons, is 17 mm.  Each of those UIM's has to have a precisely calibrated physical profile to ensure swift  operation without unintended activation.

Photo 6 Canon DSLR Style

How Many Scroll Wheels ?  My work indicates that IFthe UIM cluster described above is in place and IF there  is a JOG lever correctly positioned for thumb activation then only one Scroll Wheel is required.   The Scroll Wheel changes both Aperture and Shutter Speed in Manual Exposure mode.  In Manual Mode the function of the Exposure Compensation Button automatically switches to  toggle Scroll Wheel action between Aperture and Shutter Speed.  If the UIM's are all correctly positioned in three dimensions the process of adjusting Aperture and Shutter Speed  is quick and becomes almost instinctive.

Photographs

Photo 1, Optimum MDSW Layout.  This photo shows one of my mockups. The Shutter Release Button and Scroll Wheel are optimally angled and positioned on top of the parallel type handle. ISO and Exposure Compensation buttons (both with user selectable function) are optimally located.  It is very easy to locate and operate these four UIM's by feel without shifting grip with either hand. All primary and secondary exposure parameters can be quickly adjusted by the right index finger using this UIM layout.

Photo 2, Good MDSW Location.  This a Samsung NX11, showing good Shutter Release Button position, with the Scroll Wheel 13 mm behind and on the same level, where it is easy to find and operate by feel.  Unfortunately some of the other buttons are not so well located.

Photo 3, Poor Front Location.  The Scroll Wheel on this Canon  G12 is obstructed by the third finger of the right hand in normal hold position. Therefore the right hand grip on the camera has to be released in order to get the index finger onto the Scroll Wheel.  Good idea, poor implementation.

Photo 4, Difficult Rear Location.  The Scroll Wheel on this Panasonic G3 extends from it's housing only about 1 mm. Therefore it must be operated by the very tip of the thumb, just below the nail. You can see the cramped, awkward  hand position which results from this constraint. You can also see the right hand has barely any grip on the camera while operating the Scroll Wheel.  

Photo 5, Poor Rear Location.  The scroll wheel of this Fuji X10 is located right where the thumb wants to be in basic grip position.  In this photo the thumb is pressing on the small thumbrest right at the edge of the camera body. This position is cramped and awkward as you can see in the photo.  There is a brisk trade in after market thumb rests for this and other cameras with the same problem from the same maker.

Photo 6, Canon DSLR Style.  This is a Canon EOS 60D which has a comfortable, well designed grip and mostly well designed UIM layout. However it could easily have been much better. The Scroll Wheel is not on the same level as the Shutter Release Button and is a little further away than optimal. The ISO button is one of four identically sized buttons behind the Scroll Wheel, identified only by a tiny nipple on top, so it is difficult to find by feel.   There is plenty of room on this camera for a more ergonomically productive arrangement of UIM's near the Shutter Release Button. I would describe this camera as a missed opportunity to achieve excellence.

The Lens Lottery

THE  LENS  LOTTERY

Author  AndrewS  May 2012

Introduction  I have enjoyed making photographs and working, or just messing around with cameras for almost 60 years. Along the way I have bought and used many cameras and lenses. In the early days  I assumed, perhaps incorrectly, that one copy of a particular model lens would be the same as the next copy for all practical purposes. However in recent times I have developed the habit of systematically testing every new lens which comes into my hands.   This practice has revealed great variation between copies of many lenses together with a high rate of defects and problems.

Here follows a list of the lenses I have purchased new over the last few years with some comments about each and the cameras which drive them.  Yes, I am a confessed cameraholic, but eBay helps to offset  the cost of my addiction.  So here they are, in vaguely alphabetical order:

Canon EF 70-200 mm f4 L IS   This is the nearest thing to a perfect lens I have ever owned. It is optically and mechanically superb, OIS works really well and it's not outrageously expensive for such a fine optic.  This one gets a STAR  rating from me.  Unfortunately the Canon 60D camera which I chose to drive this lens is not up to the same lofty standard. I thought I would use this combination a lot, but don't for two reasons. First, my Panasonic GH2 with Olympus 40-150 mm lens delivers 95% of the image quality at a fraction the size and weight. Second, the 60D  is plagued  by capriciously inaccurate autofocus to the extent I cannot rely on my photos being in precise focus. Perhaps a more expensive EOS camera body would fix the AF problem, but I am not encouraged by ongoing reports of AF inaccuracy from the EOS 7D and have no interest in going up to full frame. Even if I did the 5D2 has an underwhelming record on AF performance, with many complaints in user forums. By comparison the GH2 nails correct focus with near perfect consistency in single shot operation.

Canon EFS 15-85 mm IS  [First copy] This was returned to the vendor, faulty with obvious decentering, producing marked softness on the left side.  The  [Second copy] was good.  When focussed correctly this lens delivers excellent resolution at all focal lengths.  Unfortunately focus with the 60D is erratic especially at the wide end in SLR mode with the mirror down. In live view mode the camera uses contrast detect AF which is extremely slow, more accurate but still prone to errors.

Canon EFS 17-55 mm f 2.8 IS   This is a good lens with which I made many documentary photos. It would not focus reliably at the wide end on EOS 20D or 40D. The workaround for this was to zoom out to the long end, set AF then zoom back to the wide end. Tedious.

Canon EFS 18-55mm IS kit lens [First copy]  This was the Mark1 version which was surprisingly good optically. I got a good copy in the kit lens quality lottery. AF accuracy was unreliable on Canon EOS 450D.  The [Second copy] was the mark 2 version which is supposed to be better, but I got the wrong lottery ticket and ended up with a bad copy, soft on one side at the wide end and soft on the other side at the long end.

Canon EFS 55-250 mm IS budget zoom  [First copy]  This was the Mark 1 version which was surprisingly good and a real bargain. I should have kept it because the  [Second copy]  the Mark 2 version was not as good, with decentering and  marked softness with loss of contrast at the long end.

Olympus 40-150 mm  This compact Micro 4/3 lens is a  STAR. It delivers most of the performance of  more expensive lenses.  It lacks IS but that has not been a problem for me on the Panasonic GH2.  It should be perfect on the Olympus EM5.

Olympus 75-300 mm  This is another M43 lens from Olympus with very compact dimensions for it's focal length range. No problems but the optical quality is not quite up to that of the Panasonic 100-300 mm.

Pansonic 14-45 mm OIS  I have used two copies of this M43 standard zoom and both have been STARS  with very good to excellent image quality across the focal length and aperture range and no mechanical or optical defects.

Panasonic 14-42 mm OIS kit zoom  My copy of this was faulty.  Optically it was reasonable but it was unpredictably prone to double imaging for reasons I never determined, maybe a case of Shutter Shock Syndrome  (See my post about S.S.S. on this blog) involving the OIS module.

Panasonic 45-200 mm OIS I have used two copies of this both showing the same characteristics.  From 45 to about 120 mm focal length the lens delivers very decent results. But at the long end it exhibits loss of contrast and sharpness with a tendency to misfocus even on the GH2 which has an exemplary focussing performance with most M43 lenses.

Panasonic 45-175 mm PZ OIS  Presumably this was intended to be Panasonic's upgrade  to the somewhat outdated 45-200 mm. I bought one in November 2011 and found it to be totally unserviceable. It was faulty with severe jitter effect (double imaging) in all operating conditions. It went back to the vendor for a refund.  Some, but not all, users have reported the same problem. I have not yet seen any acknowlegement from Panasonic that a problem even exists.

Panasonic 100-300 mm OIS  This is another super zoom lens for M43, with overall very decent performance. My copy shows a bit of decentering evidenced by softness on the left side at most focal lengths. Ortherwise it is a good lens suitable for hand held use on Panasonic OIS bodies.

Samsung NX 18-55 mm IS  My [First copy] of this was a bit soft at the long end but otherwise turned in a very decent performance for a budget kit zoom. The [Second copy] was even better with good sharpness at all focal lengths.

Samsung NX 30 mm f2  This is a STAR lens in Samsung's lineup, with an excellent rating in all aspects of performance.  A very small lens with a big performance.

Samsung NX 20 mm f2.8  My [First copy] of this was a poor performer with low resolution and poor resistance to flare. It was retured to the vendor. The [Second copy] was better, delivering good sharpness stopped down a little. But the flare problem remained.

Samsung NX 50-200 mm OIS  My [First copy] of this is slightly decentered evidenced by a little softness on the right side at 200 mm. This one also has a slightly sticky zoom action. I tried two further copies to see if I could find a better one. The [Second copy] was faulty with poor sharpness at the long end so it went back to the vendor. The [Third copy] had a nice smooth zoom action but was not quite as sharp as Copy 1 at the long end. So I kept the first one.

Summary  Of the 25 lenses listed here, one was completely unserviceable on delivery. This and 3 others were returned to the vendor as fauly. Seven others had faults or defects impacting on image quality. Fourteen had no faults or defects. That is a rate of  56% with no obvious faults and 44% with a fault or problem affecting operation and/or image quality.

Conclusion   As you can see from this experience, the bad copy rate in new lenses is disappointingly high. There does appear to be a tendency to less problems in the higher price range but even expensive lenses are not immune from trouble. I see no trend to prefer one manufacturer over another.   It would appear from my reading of reviews and reports that all brands have a percentage of  bad copies.   The further disappointment about this issue is that lens makers rarely acknowlege problems publicly and rarely issue recalls.

Recommendation to buyers     My suggestion is to buy from a vendor which guarantees replacement or money back on return. The rate of bad, or at least "not best" copies is so high that any buyer who acquires more than 2-3 lenses is almost guaranteed to encounter a problem. You may find it worth buying from a real shop with a real live sales person who you know by name, and more importantly who knows you and respects your judgement.

I suspect that most retail customers who report a "problem" with a camera or lens are probably not using their equipment correctly. So, when you present yourself to the vendor claiming to have faulty equipment make sure you have in hand  good evidence in the form of hard copy photographs illustrating the problem.