Autofocus / Manual Focus Performance and Metering
A key advantage of the Olympus OM-D E-M5 when compared to other mirrorless cameras from other manufacturers, is its fast and accurate autofocus system. While others are struggling with autofocus performance, bringing hybrid autofocus innovations to improve the speed of autofocus systems, Olympus figured out a way to make contrast detect autofocus work incredibly fast. Autofocus, by far, has been my biggest frustration with other mirrorless cameras on the market. The only cameras with acceptably fast AF have been the Nikon 1 cameras – the rest have AF issues, some more serious than others, with some failing to acquire focus even in broad daylight situations (Canon EOS M). After the Nikon 1, it was hard to get used to any other mirrorless camera in terms of autofocus speed. So after hearing all the praises of the E-M5’s autofocus performance from fellow photographers, it was the first thing I decided to test. My first test took place in a dimly-lit living room – I pointed the camera at the lens box and half-pressed the shutter. The camera acquired focus immediately, without any hesitation. I then tried refocusing on other objects in the room, some of which were in darker areas and less contrast. Again, the camera did not even hesitate. This already impressed me, because I have not seen such quick and accurate AF performance on any mirrorless camera. The Nikon 1 cameras are very fast in broad daylight, when its hybrid AF system kicks in. But as soon as you step indoors to a dimly lit environment, Nikon 1 starts to suffer badly, with contrast detect going back and forth trying to acquire focus. The Olympus OM-D E-M5 did not seem to care whether I shot outside in daylight or in a dim environment indoors – focus was very fast and dead on each time in single shot (AF-S) mode.
Continuous (AF-C) mode, on the other hand, is not that great – the camera continuously scans for focus back and forth, trying to find any changes in the subject (quite normal for a contrast-detect autofocus, by the way). Very similar to what Sony NEX and other mirrorless cameras do in AF-C mode as well. If you mistakenly end up choosing AF-C for regular stills, you might get quickly frustrated with the E-M5, because it will do this back and forth motion constantly, sometimes failing to acquire focus even on subjects with plenty of contrast. I tried photographing a Taekwondo competition in AF-C mode, even in bursts, and it was tough. Ended up with plenty of out of focus images, because the sport is very fast and erratic – a typical nightmare for an autofocus system. Subject tracking did not work well, constantly losing the tracked subject. This is one of the few examples that was actually in focus:
I quickly got frustrated with the results, so I switched back to AF-S and tried to shoot some more. I ended up keeping AF-S instead of AF-C, because the number of keepers was about the same, but at least I could occasionally take photos of athletes resting between the rounds. With AF-C, that constant back and forth motion just annoyed the hell out of me.
Gladly, I had my Nikon D800 + 70-200mm f/4 with me, so I switched to that configuration instead and ended up with much better shots like this:
Seems like even some of the best mirrorless cameras are still rather weak for fast action photography. So if you are a sports photographer, you will still be better off with a DSLR for faster and more reliable continuous AF + subject tracking. I experimented some more with the AF-C mode on the E-M5, photographing my kids playing soccer later. This time, the results were a little better, probably because they were not running as fast or moving in different directions as often as the Taekwondo kids. It looks like AF-C works better with subjects moving towards the camera, but not so well for side to side motion (just my temporary observation for now).
As for manual focus operation, the E-M5 has the ability to zoom into the image for more precise autofocus accuracy from 5x to 14x and the screen looks great with no traces of interpolation. Once you enable AF-S + MF as the AF Mode and turn MF Assist On, you can acquire focus on a subject, then as you start turning the focus ring on the lens, the camera will automatically zoom in for you for much more precise manual focusing. I used this feature quite a bit and it worked very well every time. The only bummer is that the E-M5 does not have a focus peaking feature, as I stated earlier in the review.
Metering is generally pretty good and nothing to complain about. As for the exposure though, after performing a number of different tests, I found the Olympus OM-D E-M5 to slightly underexpose by about 1/3 of a stop. This has nothing to do with metering – it is the camera that has wrong ISO values. When testing the camera side by side with other mirrorless cameras, I used exactly the same aperture, shutter speed and ISO, and the E-M5 would constantly underexpose. Why am I blaming the E-M5 for this? Because it was the only camera that produced inconsistent exposures when compared to other mirrorless cameras, every single time. ISO 200 is not really 200 – it is more like ISO 160. I am not sure what the source of the problem is, but it did prolong my testing efforts. Since I did not want to mess with exposure differences and modify my setup for the E-M5, I ended up not compensating for this exposure difference after going through a number of different test scenarios. So when you start looking at camera comparisons on the next pages of this review, keep this in mind, as images from the E-M5 will appear a little darker. Do not worry about this though, since the exposure inconsistency will not have any impact on your photography.
Movie Recording
The Olympus OM-D E-M5 can record 1080i full HD movies at 60 fps for smooth playback, which is nice, but there is no 1080p mode available. You can also pick lower resolution movie format for smaller movie files. Another advantage of the movie mode is that you can fully control the exposure while recording movies – you can easily adjust aperture, shutter speed and ISO when shooting videos in Manual mode. If the scene you are recording is too bright or too dark and you are in one of the P/A/S modes, you can also use exposure compensation to adjust the brightness level. The camera LCD will reflect these changes and you will see exactly what you are capturing. Autofocus and subject tracking both work when recording videos and the 5-axis image stabilization technology helps quite a bit in keeping the camera stable.
Dynamic Range
Dynamic range is an important metric of sensor performance, especially for landscape photography. I spent some time measuring the dynamic range of the Olympus OM-D E-M5 in a lab environment using Imatest and despite the smaller sensor size (compared to APS-C), it produced very impressive dynamic range staying close to the Sony NEX cameras in performance. As with all digital cameras, increasing camera ISO also decreases dynamic range, so shoot at base ISO of 200 if you want to preserve the most amount of information on your photographs.
Let’s see how the camera does in ISO performance against other cameras. Choose the next page below.