Tuesday, September 2, 2014

Olympus OM-D E-M1 Review


The Olympus OM-D E-M1 on paper looks like a higher-spec version of the well-received E-M5. In real-life use, it is much more like the a shrunk-down semi-pro DSLR than it is a pumped up version of a mirrorless camera. This isn't to say that DSLR's are inherently better than mirrorless cameras, but that too often mirrorless cameras lean on the "consumer electronic" side of the equation rather than being "photographic tools." In your hands, the E-M1 makes you "feel like a photographer" in a way that cameras like the Sony A6000 or Samsung NX300 don't. The headline specs are:

  • 16MP MOS sensor with no low-pass filter
  • On-sensor phase detection
  • '5-axis' image stabilization with automatic panning detection
  • ISO 'LOW' (100 equiv) - ISO 25,600
  • Up to 10fps (6.5 fps shooting with continuous AF)
  • 1.04M-dot 3" LCD touchscreen display
  • Electronic viewfinder: 2.36M-dot LCD, 0.74x magnification
  • Built-in Wi-Fi 
  • Dust, splash and freeze-proof (to -10 °C)

In almost all aspects, this is as contemporary as a camera can get in terms of a feature list. That says nothing about how well those features actually perform, and what is more important... is how those features work together.

Body and Design


Though it is still a small camera, the E-M1 ostensibly apes the design of larger DSLR's. It would be easy to label the design as "retro" but there is nothing retro about using it; the E-M1 is not a camera that is mimicking a bygone era. The button and dial placement are thoroughly modern and in keeping with the needs of operating in a digital frame of mind. It's not just about the ostentatious protruding grip/battery-chamber; the overall philosophy of the control layout is perhaps the closest of all the mirrorless cameras to what DSLR users are familiar with. The point is not that the camera has lots of manual controls (it does), but that those controls have some semblance of being prioritized for serious use. Unfortunately, this is Olympus, so there are some strange design choices thrown into the mix... and then there is the matter of how the software menus are laid out... but the overwhelming tactile impression is that you are using a tool, not an electronic gadget.


For the most part, the top of the camera is fussy but functionally laid out. The on-off switch is inconveniently placed if you are used to the Nikon setup of having it on the right index finger, but will be more familiar to Canon users. The left control pod controls shutter and focus behaviour. There's a push-pin lock on the mode dial. As a nice ergonomic touch, one push of the center pin locks the mode dial, and a second push unlocks the dial. In other words, you don't have to use the push-and-twist motion that some cameras (Nikon D7100 and Df) require to operate their control dials. One very strange default choice on the part of Olympus is that the Fn2 button controls the tone-curve of the output image. This can be changed, but it is strange to assign it as a default function on a button that could be used for more frequently used functions.The control dials a prominently placed. Note how far forward the battery chamber extends.

Speaking of the grip; it's just a bit shy of perfection. It's deep, easy to hold and allows for your index and thumb to fall right onto the front and rear control dials. Unfortunately, the ledge where your middle finger rests has a bit of a twist to it. This gives the tactile impression that the camera is slowly creeping to the left and out of your grip. It never actually does, and it's the only downside to the part of the camera that has the most immediate connection to the user.

Like the FujifilmX-T1, the E-M1 boasts a large electronic viewfinder with a fast refresh rate. In daylight use, the projected image is smooth and crisp, though the refresh rates does suffer when light levels fall. DSLR shooters who are used to holding a camera up to their eyes will fell right at home with the E-M1; though no EVF is as "fast" as an optical viewfinder, the EVF on the E-M1 (like the optional one on the E-P5) is certainly "good enough" for the majority of shooting.


There's a high degree of customization available. It stars with the split-mode 1-2 switch on the back of the camera. The default setting is that mode 1 allows for the aperture/shutter to be adjusted by the control dials, with mode 2 controlling ISO and WB. Note that in aperture priority mode, you the secondary dial can be set to EV compensation, but it can't be set to ISO control.

The default setting of the rear-LCD display can fool you into thinking that the output will be more contrasty and saturated than it is. Sky's that look like they are reasonably well exposed and a deep blue will appear slightly more faded when the file is viewed on a computer monitor.


As well laid out as the physical controls are, the menu system itself is byzantine. The problems with virtually all Olympus menus can be classified into two sins: 1) Things that you would think that are grouped together are not grouped together, and 2) Things that are usually called on thing by other camera makers classified as another by Olympus. In truth, it's not that the menus are unworkable; the issue is that organization is un-intuitive and the learning curve is steep.

There is only one memory card slot, but thankfully, the buffer is large enough to match the shutter burst rate. All you really needs is a Class 10 card if you aren't processing heavy volumes of data; the same is true for video as well as stills. Battery life for the E-M1 is rated to approximately 350 shots under CIPA protocols. In everyday terms, this means that the battery will last through a day of shooting and video if you are conservative with how long the LCD and EVF displays are on.



Olympus 25mm ƒ/1.8 M.Zuiko Digital



All of the shots done with the E-M1 in the post were with the Olympus 25mm ƒ/1.8 M.Zuiko Digital prime lens. As a m4/3 analogue of a 50mm full-frame lens, it does the trick. The construction is a bit plastic and there isn't a dedicated aperture ring, but the optical quality is excellent. It's lightweight and smaller than the Panasonic alternative, the Panasonic Leica DG Summilux 25mm f/1.4 ASPH Micro 4/3. The Olympus is a lens that can be shot wide-open at f/1.8 without significant image quality penalties. Sharpness is consistent across the frame even at maximum aperture, and vignetting and chromatic aberration are well controlled. Like many modern lenses, this is a lens with a fast focus throw, and combined with the E-M1, single-shot focusing is extremely fast and quiet.

Autofocus Performance


First a word about AF control. For many shooters, the ability to quickly move the focus point around the frame is an important part of composition and good shot discipline. If you are contentious about shooting, this is an action that you using often. The unfortunate thing is how many cameras get this wrong. The Sony A6000 is abysmal in this regards, as you can't move the AF point without some combination of multiple button presses. Most of the advanced Panasonic cameras are a little less fidgety, but the gold standard is Nikon, where every DSLR that they make allows for the AF point to be adjusted from a dedicated control pad on the back of the camera. And so it is with the E-M1. The default operation of the 4-way controller around the "OK" button is to move the AF point. You don't have to unlock this feature in a separate Fn button... if you don't want to. The ease of which the AF point can be moved is one of the things that makes the E-M1 fell like a more substantive and serious camera than the rest of its mirrorless competitors.

Summing up the autofocus performance of the E-M1 is problematic because the system is absolutely brilliant if taken as a whole. Focus speed with native m4/3 lenses is extremely quick for still subjects. For subjects that are moving in a straight line towards the camera, the camera will capably perform motion tracking. Unfortunately, things fall apart when the camera is asked to track side-to-side motion. In such situations, the AF system flatters to deceive. Initial focus lock is quick, but one of two things can go wrong. The first is that the focus locks stays in place and doesn't follow the subject after initial lock; when this happens, more often than not the camera is locking on the scene behind the subject. If adequate lock is achieved for a moving subject, there is also the possibility that the the camera will lose it while the subject is moving.

What seems to be happening is that that the phase detection hardware works as intended with motion that is purely depth-related (fore-aft) in relation to the camera, but that the camera is weaker with the pattern recognition required to track lateral movement. In order to do this, the camera has to recognize patterns and colour... in addition to the depth information provided by the phase/contrast detect algorithms. If you push the system, you will find that in some cases where the camera just barely maintains tracking of the subject, the focus point will drift off of your initial focus lock. This happens with most AF systems, but the E-M1 is a little less robust in this regards. The end result is that the E-M1 is capable of tracking moderately fast moving subjects (walking people), but it is not as good as the Panasonic DFD system, Sony A6000. or any of the advanced DSLR's when it comes to erratic/fast subjects (sports, animals, etc.)

Coming back to the phase detection system, this is the one thing that makes the E-M1 a good camera for bringing legacy Four Thirds lenses into the mirror-less era. Without PDAF, mirror-less cameras use an advanced form of contrast-detect to focus (CDAF). CDAF on a mirrorless camera is faster than the same on a DSLR because of the way that m4/3 lenses are designed. The CDAF mechanism rocks the lens back and forth at a very high speed in order for the camera to recognize changes in contrast. the difference between DSLR's and mirrorless cameras is that mirrorless lenses are specifically designed to do this. Older Four thirds lenses work like DSLR lenses, and can't be shifted back and forth rapidly. However, if you pair them with the E-M1, the on-chip phase detection replicates the action of a traditional dedicated PDAF unit.

Vancouver might have a reputation for laid back people, but it also has a contingent of rather aggressive seagulls. Watch your food if you are eating outdoors along False Creek. Here is an example of the autofocus not being able to lock on to a moving target. The lock was acquired with the bird in mid-air, but the problem is that the target lock didn't follow the bird at all. Hence, the point of focus being quiet a bit behind the point of capture.


Here's a more successful attempt. Focus lock achieved and  continuous tracking as intended. Note that the difference between this example and the previous one is that the seagull is coming directly at the camera, which is easy for the PDAF sensors to handle, whereas in the previous example the flight path is across the sensor, which poses a challenge for the AF system.

ISO 100, f/1.8, 1/8000s

Image Quality


Gone are the days when m4/3 cameras were looked down up on for having tiny and noisy sensors. The image quality from the E-M1 is competitive with output from cameras with larger sensors. The only draw backs are that the resolution is less and the depth of field is greater per indicated aperture, but that's pretty much it.

General Usage


The hallmarks of good sensor output is low image noise and high dynamic range. The E-M1 is competitive with other cameras in this respect. In bright midday light, there's adequate dynamic range to work with, especially if you shoot RAW. As the light decreases, shadow noise is well controlled up to ISO 1600. This is a sensor without an anti-aliasing filter, so there is an added amount of bite and acuity that previous m4/3 sensors didn't have. Images are crisp and don't require much sharpening in post processing when shot with a decent lens.

ISO 200, f/5.6, 1/320s
Granville Island Public Market ISO 200, f/3.2, 1/50s
Steveston Village Docks. ISO 1600, f/1.8, 1/60s

Overall Image Noise


There's a misconception that m4/3 sensors are noisier than APS-C sensors because they are smaller. It's easy to see why this perception arose because the older sensors by Panasonic and Olympus lagged behind those made by Sony in terms of technology. However, given equal terms in manufacturing technology, cameras with similar photodiode sizes should show similar levels of performance when it comes to image noise and dynamic range. In other words, all things being equal, a 16mp m4/3 sensor should perform as well as 24mp APS-C sensor, with the only practical downsides being less resolution and less depth of field control. Put another way, if your ISO comfort point for an APS-C camera is roughly between ISO 1600 and ISO 3200, then it will be roughly the same on the E-M1.

The following is an ad hoc demonstration of the camera's JPEG output quality through the ISO range. Pay attention to the legibility of the soda bottles for detail retention (or lack thereof) as the ISO value rises, speckling in the broad colour patches for overall image noise, as well as the harshness of the reflections and shadows as dynamic range decreases. These samples are not directly comparable to similar samples found elsewhere in this blog because of variable ambient lighting conditions. Click on images for 100% crop view.

ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200
ISO 6400
ISO 12800

The comfort point for care-free shooting in JPEG (at default noise suppression)  is roughly ISO 1600. It would be higher were it not softening from the in-camera noise suppression. ISO 3200 is still usable so long as your subject fills up a good portion of the frame and there isn't a requirement for fine detail. ISO 6400 is good only for emergencies.

Fixed Pattern Noise



Read noise is the portion of image noise that is produced by drawing the collected image data off of the sensor chip, i.e., noise produced while the data is read off of the chip. It's appearance can be depicted by producing an extremely short exposure in absolute darkness (e.g., with the lens cap on). At ISO 12800, the exposure is still relatively black, but there is a hint of texture in the image. The following is a 7EV push to illustrate the texture of that noise. Click on image for 100% crop view.

ISO 12800, 1/8000s, 100% crop, 7EV push

The read noise has an even and finely distributed speckled texture that produces pleasing images as the ISO levels increase. There's a hint of banding that will show up if you do aggressive shadow lifting, but it won't be intrusive.

Here is the same, only at 1 second exposure. The presence of dark-current noise is more evident. This is the noise contributed by the inherent electrical properties of the camera circuity. The texture of the noise is blotchier, but manageable.

ISO 12800, 1s, 100% crop, 7EV push

However, if you try for a 30s exposure at this ISO level (night sky, etc), you get this result:

ISO 12800, 30s, 100% crop, no push

The upshot is that in most low light situations, the noise characteristics allow for pleasant looking images, but that long exposure work might be best done with another camera.

Image Stabilization


On of the striking things about the E-M1 is that you can see the sensor wobble in its mounting when it is exposed. This is an indication of how much leeway the micro-motors have to position the sensor in order to compensate for handshake. The genius of the E-M1 is that the smaller sensor-size is virtually a non-issue so long as outright bokeh is not your priority. The Olympus 5-axis image stabilization system is very likely the best in-camera image stabilization system on the market, and arguably the best performing of any system (body or lens-based) for focal lengths under 100mm full-frame equivalent. With the E-M1, you spend less time thinking about your ISO levels and safe hand-held shutter speeds than you do with any other camera. This requires some getting used to, as the acceptable shutter speeds can be disconcertingly low with this camera. Most image stabilization systems reach a performance floor when the shutter speed falls below 1/10s, but if you are exceptionally steady, at wider focal lengths you can pull off a usable hand-held exposure time of one second. That is unheard of with any other camera.

Here's a sequence from moderately dark to quite dark.  Here is an after-dusk shot of the crowd watching filming of "Once Upon a Time" in Steveston Village. The street looks like that because of the amount of flood lighting that they use during filming.

ISO 1600, f/1.8, 1/50s

Walking around the block and down to the docks, you can see just how powerful the floodlights are for filming a street scene at night. One big light, one tall crane

ISO 1600, f/1.8, 1/20s

Facing away from the village towards the public docks, the light is pretty much full nighttime conditions. (Roughly 9:45pm at night.)

ISO 1600, f/1.8, 1/20s

The darkest location is out on the river, away from the artificial lights:

Fraser River. ISO 1600, f/1.8, 1/25s

All of these were shot hand-held without any extra bracing techniques. All save the first image were shot at shutter speeds below the 1/effective focal threshhold. Even when the original pictures are examined at the pixel level, there is hardly a trace of any motion blur.

Here's an example of how the stabilization system works during video recording:



Comparisons




The natural competitor to the OM-D E-M1 is the the Fujifilm X-T1. Both camera bodies are priced at roughly the same level, and comparable lenses are similarly priced. Both bodies appeal to DSLR users who want to downsize but who don't want to give up image quality or functionality. So which to choose?

Quite simply, the X-T1 takes better pictures by virtue of having the larger sensor, the E-M1 is the superior camera. Autofocus performance is better on the E-M1, both in terms of speed and motion tracking. Ergonomics is much better if you ignore the menu structure of the E-M1. The X-T1, like the X-E2, is operationally a like a film camera. There's a direct correlation between manual controls and what the camera is doing, but its really a camera that you set up to use in the way that you prefer, and which you then leave alone. The E-M1 follows a more modern paradigm and is quicker to change settings on the fly.

The X-T1 will produce better images because of its larger photodiodes, but the X-Trans sensor can be contentious in some circles because of the way that it treats fine-detail, particularly in the red and blue channels. Lens selection is good for both systems, with high quality options being available for both cameras. However, the m4/3 lens selection is more varied and complete. This is true for longer focal length, as m4/3 not only has more options, focus performance tends to be better than on the X-system. No matter which lens you use with the X-T1, either XF 55-200mm or the XC 50-230mm, the Fujifilm cameras aren't as quick to focus with long-focal lengths as they are at sub-60mm focal lengths.

Concluding Thoughts


In a way, the Olympus OM-D E-M1 finds itself in the same position that Mazda cars do in North America: everybody raves about it, but it just doesn't sell as well as the competitors that are not as premium and which are closer to the mainstream portion of the market. Price is ostensibly the problem; for almost the same amount of money that you would pay for the body alone, you could have a Nikon D7100 or Canon EOS 70D with a kit lens. However, once you are past that hurdle, the availability of high quality lenses in the Micro Four Thirds world makes owning an E-M1 a joyous experience for those who like to travel light.

The OM-D cameras make for excellent travel and documentary cameras, especially when paired with prime lenses. The immediacy of the control response and the sheer brilliance of the image stabilization system elevates this camera very close to the ideal of being a take-anywhere, shoot-anytime camera. For anybody stepping up to the E-M1, the control layout and multiple ways in which the camera can be adjusted will be intimidating at first, but the learning curve is not insurmountable. The image quality will be enough to satisfy those stepping down from a larger sensor system. The downsides are primarily with the chunkiness of the menu system, and that autofocus motion tracking isn't up to DSLR standards for those who have come to rely on such. This is a bit of a shame, as the E-M1 is definitely a professional-quality camera, but its not quite up to the task of taking over a professional quality DSLR for the most demanding situations.

Granville Island. ISO 100, f/8, 1/320s

Public Market ISO 200, f/1.8, 1/200s

Public Market. ISO 200, f/1.8, 1/200s

Ocean Concrete sculpture by i.e. creative. ISO 100, f/1.8, 1/3200s

Ocean Concrete, painted by OSGEMEOS. ISO 100, f/6.3, 1/1000s

In summary, the platitudes for this camera are well deserved. The highs are quite high; the lows aren't truly that low, but are a bit on the frustrating side considering how good the rest of the camera is.




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