Olympus E-M5 Exposure

Saturation & Hue Accuracy
Accurate saturation and very good hue accuracy.

Saturation. The Olympus E-M5 pushes reds a fair bit, but most other colors are pretty close to bang on in terms of saturation. Default saturation is 106.1% (6.1% oversaturated), which is lower than average; that is, it's more accurate than most. Saturation remains fairly stable across the ISO range, except at the highest ISOs, where it falls off. You can always adjust saturation, or select a different picture mode to adjust color to your tastes. Most consumer digital cameras produce color that's more highly saturated (more intense) than what's found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. Here, when white balance was adjusted to match lighting, the Olympus E-M5 did reasonably well, producing fairly natural-looking Caucasian skin tones that were on the pinkish side. Darker skin tones show more warmth, but were still realistic. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Olympus E-M5 did push orange toward yellow, light greens toward yellow, and cyan toward blue, but all shifts were relatively minor. (The cyan to blue shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors, though the E-M5 shifts less than most.) Overall hue accuracy was very good with a Delta-C color error of only 3.91, much better than average. Hue is "what color" the color is.

Saturation Adjustment
The Olympus E-M5 lets you adjust the image saturation, contrast, and sharpness in five steps each. As can be seen below, the saturation adjustment was quite effective, covers a useful range, and does a good job of not impacting contrast.

The table above shows results with the default as well as the two extreme saturation settings. Click on any thumbnail above, then click again to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Very warm cast with Auto White Balance, and cool with 2,600K setting, but good color with the Incandescent and Manual settings. Average exposure compensation required.

Indoors, under normal incandescent lighting, color balance was very warm and orange using the Auto white balance setting. Results with the Incandescent setting were quite good and just a touch warmer than the Manual setting, which was the most accurate. The 2,600 Kelvin setting was quite cool with a blue-green tint. The Olympus E-M5 required an average amount of positive exposure compensation here, at +0.3 EV. (Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.)

Outdoors, daylight
Natural looking colors, with about average exposure accuracy.

Outdoors, the Olympus E-M5 performed well, with good color though exposure was a little dim at default settings. We preferred the skintones with the Manual white balance setting in our "Sunlit" Portrait shot, but Auto wasn't far off the mark, though both were on the pinkish side. The Olympus E-M5 required an average amount of positive exposure compensation (+0.7 EV) to keep facial tones reasonably bright. Default contrast was a bit high, but despite the bright appearance there were only a few blown highlights in the mannequin's shirt and flowers, which is much better than average. The Far-field shot was slightly underexposed at default settings, but had no blown highlights, though there were some deep shadows. Noise in all but the deepest shadows was however surprisingly low for a Micro Four Thirds camera.

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
Very high resolution, ~2,200 lines of strong detail in JPEGs, up to about 2,300 lines from processed RAW files.

In camera JPEGs our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,200 lines per picture height in both the horizontal and vertical direction before aliasing artifacts started interfering with the pattern. Complete extinction of the pattern didn't occur until about 3,200 to 3,400 lines, though. Adobe Camera Raw was able to extract a bit more resolution, to about 2,300 lines in both directions, though color moire was much more apparent than camera JPEGs. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Very good sharpness overall, though some edge-enhancement artifacts on high-contrast subjects are visible. Mild noise suppression visible in the shadows.

Sharpness. The Olympus E-M5 captures sharp images overall, though edge enhancement artifacts such as sharpening halos are visible on high-contrast subjects such as around the thicker branches and pine cones in the crop above left. Still, better than average results here. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows some fairly mild noise suppression artifacts in the darkest areas of the model's hair, smudging individual strands together, though quite a few strands remain visible. Overall, detail is very good for a Micro Four Thirds model. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

RAW vs In-Camera JPEGs
As noted above, the Olympus E-M5 produces sharp, detailed in-camera JPEGs, though with visible sharpening artifacts at default settings. As is almost always the case, though, more detail can be obtained from carefully processing RAW files than can be seen in the in-camera JPEGs. Take a look below, to see what we mean:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking on the link will load the full resolution image. The super fine camera JPEG and Olympus [ib] conversion used default settings, while Adobe Camera Raw conversion was sharpened in Photoshop using unsharp mask of 300% with a radius of 0.3.

As you can see, the Olympus [ib] conversion resulted in an image very similar to the in-camera JPEG in terms of detail, color and contrast. The Adobe Camera Raw (version 6.7) conversion however shows improved fine detail compared to the in-camera SuperFine JPEG and Olympus software conversion at default settings (especially noticeable in the pine needles), though it does show a bit more noise as is usually the case. Nevertheless, the E-M5 rewards RAW shooters with excellent detail when using a good quality RAW converter. By comparing full resolution images, you can also see that we were able to recover the clipped highlight detail in the clouds above the crop area using Adobe Camera Raw, another advantage of shooting RAW.

ISO & Noise Performance
Very good noise versus detail up to ISO 1,600.

The Olympus E-M5's images are quite clean and detailed at ISOs 200 though 800, though some minor chroma noise is visible in the shadows. At ISO 1,600, we see some minor detail loss due to stronger noise and noise reduction efforts, as well as more visible chroma noise in the shadows, but detail is still very strong. At ISO 3,200, additional blurring occurs reducing fine detail, though chroma noise is better controlled. ISO 6,400 shows a lot more luminance noise, as well as another decrease in fine detail and also a reduction in saturation. ISO 12,800 is very noisy, with strong yellow blotching in the shadows. The mannequin's hair color also shifted toward yellow. At ISO 25,600, noise and noise reduction were very strong smudging out almost all fine detail, and a lot of blue, purple, and yellow chroma noise was present as well.

Overall, though, high ISO noise performance is the best we've seen from a Micro Four Thirds model thus far, and competes well with the best APS-C models. As always, see the Print Quality section below for maximum recommended print sizes at each ISO.

A note about focus for this shot: We shoot this image at f/4, using one of three very sharp reference lenses (70mm Sigma f/2.8 macro for most cameras, 60mm f/2.8 Nikkor macro for Nikon bodies without a drive motor, and Olympus Zuiko 50mm f/2.0 for Four Thirds and Micro Four Thirds bodies). To insure that the hair detail we use for making critical judgements about camera noise processing and detail rendering is in sharp focus at the relatively wide aperture we're shooting at, the focus target at the center of the scene is on a movable stand. This lets us compensate for front- or back-focus by different camera bodies, even those that lack micro-focus adjustments. This does mean, though, that the focus target itself may appear soft or slightly out of focus for bodies that front- or back-focused with the reference lens. If you click to view the full-size image for one of these shots and notice that the focus target is fuzzy, you don't need to email and tell us about it; we already know it. :-) The focus target position will simply have been adjusted to insure that the rest of the scene is focused properly.

Extremes: Sunlit, dynamic range and low light tests
High resolution with very good dynamic range. Good low-light performance as well.

Sunlight. The Olympus E-M5 did very well with this difficult shot, requiring the average amount of exposure compensation (+0.7 EV) to keep the mannequin's face reasonably bright in this harsh lighting. As mentioned previously, despite the bright appearance of the mannequin's shirt, dynamic range was surprisingly good, with very few highlights blown and very good detail in the shadows as well. Performance here was well above average compared to most Micro Four Thirds models.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here. In actual shooting conditions, be sure to use fill flash in situations like the one shown here; it's better to shoot in open shade whenever possible.)

Dynamic Range Analysis
A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)

What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work.

JPEG. The graph at right (click for a larger version) was generated using Imatest's dynamic range analysis for an in-camera Olympus E-M5 JPEG file with a nominally-exposed density step target (Stouffer 4110). At the base ISO of 200 (the optimal ISO) and with default settings, the graph shows 11.4 f-stops of total dynamic range, with 8.82 f-stops at the "High" Quality level. Roll-off at the highlight end of the curve was gradual, but for shadows it wasn't quite as well-behaved, which could lead to some visible gradation in very deep shadows. Still, these are are excellent results for a Micro Four Thirds sensor, rivaling many APS-C models. Compared to the Sony NEX-5N which uses one of the company's more recent 16-megapixel APS-C sensors, the E-M5 actually scored higher at all quality levels, though much of that has to do with differences in JPEG processing. Note though that this measurement has a margin of error of about 1/3 f-stop, so differences of less than 0.33 can be ignored.

RAW. The graph at right is from the same Stouffer 4110 stepchart image captured as a RAW (.ORF) file, processed with Adobe Camera Raw using the Auto setting, then tweaked from there. As can be seen, the score at the highest quality level increased slightly from 8.82 to 9.19 f-stops, which is almost insignificant, though total dynamic range increased over 3/4 f-stop from 11.4 to 12.2. Again, these results are much better than average for a Micro Four Thirds sensor, and almost as good as the best APS-C sensors. The Sony NEX-5N for example scored 9.95 f-stops at the highest quality level, with 12.3 f-stops total dynamic range. It's also worth noting here is that ACR's default noise reduction settings reduced overall noise somewhat (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the higher quality thresholds.

Contrast Adjustment
The camera's contrast adjustment was some help in handling the harsh lighting in our "Sunlit" Portrait and Far-field shots.

At its lowest contrast setting, the Olympus E-M5 did a better job of revealing shadow detail, while maintaining fairly natural-looking skin tones. There were few blown highlights to begin with in both these shots so the decreased contrast setting left most highlights alone, but it did bring out more shadow and darker midtone detail.

The shots above show the results of the minimum, default and maximum contrast settings. While you can see the extremes, it's pretty hard to evaluate small differences in contrast on small thumbnails like these, click on any thumbnail to go to the full-size image.  As you can see, the E-M5's contrast setting is quite effective and didn't impact saturation much, which is a good thing.

Gradation
Similar to dynamic range optimization systems from other manufacturers, the Olympus E-M5's Gradation setting applies local contrast adjustments in an attempt to preserve shadow detail and prevent highlight clipping with the Auto setting. Above are examples of the Normal (default), Low Key, Auto, and High Key settings applied to our "Sunlit" Portrait shot. Mouse over the links to load the associated thumbnail and histogram, and click on the links to visit the full resolution image.

As you can see, the Low Key setting applies Gradation for making subjects darker (in the thumbnail and histogram above, you can see that the camera shifted levels to the left, darkening the image dramatically), while the High Key setting does the opposite for brighter subjects (shifting levels to the right so that lighter tones are blown, but darker ones are opened up). The Auto setting did a good job at toning down highlights and bringing up darker midtones without making the image too flat-looking or washed-out.

Face Detection
Like most Point & Shoot cameras these days (and many DSLRs in Live View mode), the Olympus E-M5 has the ability to detect faces, and adjust exposure and focus accordingly. As you can see from the examples above, it works well. In Aperture Priority at f/8 and ISO set to 200, the camera did the best it could by reducing shutter speed from 1/100s to 1/60s. This helped with exposure while keeping shutter speed high enough to avoid typical motion blur. In full Auto mode, the camera opened aperture to f/2 for more light and better isolation from the background, used Auto Gradation for lower contrast to produce a much brighter, more evenly exposed image while still using a fast shutter speed of 1/1250s. Again, surprisingly few highlights were blown even though the image is quite bright. An excellent performance under very difficult lighting such as this.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

Low Light. The Olympus E-M5 performed well in low lighting, capturing bright exposures at our lowest light level at all ISOs (this is partly because ISO doesn't go below 200). As is often the case, the E-M5's metering system struggled a bit with getting the exposure right at the lowest levels though, so we used manual exposure for these shots. Noise was well controlled up to ISO 1,600, though there's some chroma noise noticeable in darker shadows. There are a few bright pixels visible here and there at lower ISOs. (The E-M5 does offer pixel mapping, so hot/dead pixels can be mapped out without a trip to a service center.) White balance was quite neutral using the Auto setting, just very slightly cool at most ISOs. Some very minor horizontal banding can be seen at the highest ISOs and lowest light levels, but nothing to be concerned about.

The camera's autofocus system was able to focus on our subject down to below the 1/16 foot-candle light level unassisted with an f/2.8 lens, which is excellent for a camera using contrast-detect autofocus, and in total darkness with the aid of its focus assist lamp.

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) Thanks to their phase-detect AF systems, digital SLRs tend to do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects. The E-M5 uses contrast-detect autofocus, as is found in most point & shoot cameras, so its low-light focusing ability is less than that of most SLRs with phase-detect systems. That said, though, the larger, more sensitive pixels of the E-M5's sensor do better under dim lighting than do the tiny pixels of most point & shoots, (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

Print Quality

Excellent 24 x 36 inch prints at ISO 200; ISO 1,600 shots make great 16 x 20 inch prints; highest setting of 25,600 makes a good 4 x 6.

ISO 200 images look terrific at 24 x 36 inches, with sharp detail and rich colors.

ISO 400 shots look quite good and crisp at 20 x 30 inches.

ISO 800 images look good at 20 x 30 inches, though some softness appears in low-contrast colors and slight luminance noise is visible in shadows.

ISO 1,600 images are a bit too soft in some areas for printing at 20 x 30 inches, but 16 x 20 inch prints look just fine.

ISO 3,200 images have some fine detail that prints well at 16 x 20, but other elements are soft, so we prefer prints at 13 x 19. Most reds look decent, but our difficult red leaf swatch is quite blurry, a common outcome that we'll just stipulate from here on up the ISO range.

ISO 6,400 prints have enough detail for good 8 x 10 inch prints.

ISO 12,800 images are too rough at 8 x 10, but look better at 5 x 7. Colors flatten just a little here, particularly greens, but most colors look pretty good.

ISO 25,600 are better at 4 x 6.

Overall, the Olympus E-M5 outperforms its Pen predecessors and produces excellent printed images across the ISO spectrum.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 Mark II studio printer, and the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)