Olympus E-M10 II versus Nikon D7100

The Olympus OM-D E-M10 Mark II and the Nikon D7100 are two digital cameras that were officially introduced, respectively, in August 2015 and February 2013. The E-M10 II is a mirrorless interchangeable lens camera, while the D7100 is a DSLR. The cameras are based on a Four Thirds (E-M10 II) and an APS-C sensor. The Olympus has a resolution of 15.9 megapixel, whereas the Nikon provides 24 MP.

Body comparison

The physical size and weight of the Olympus E-M10 II and the Nikon D7100 are illustrated in the side-by-side display below. Three consecutive views from the front, the top, and the rear side are shown. All size dimensions are rounded to the nearest millimeter. You can also toggle the display to switch to a percentage comparison if you prefer that the measures are being expressed in relative terms (in this case, the camera on the left side – the E-M10 II – represents the basis for the calculations across all the size and weight measures).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Nikon D7100 is considerably larger (46 percent) than the Olympus E-M10 II. Moreover, the D7100 is substantially heavier (96 percent) than the E-M10 II. It is noteworthy in this context that the D7100 is splash and dust-proof, while the E-M10 II does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can find an overview of optics for the two cameras in the Micro Four Thirds Lens Catalog (E-M10 II) and the Nikon Lens Catalog (D7100). Mirrorless cameras, such as the Olympus E-M10 II, have moreover the advantage that they have a relatively short flange to focal plane distance and can thus use many lenses from other systems via adapters.

Concerning battery life, the E-M10 II gets 320 shots out of its BLS-50 battery, while the D7100 can take 950 images on a single charge of its EN-EL15 power pack.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you want to switch the focus of the display and review another camera pair, just select a new right or left comparator from among the camera models in the table. Alternatively, you can also move across to the CAM-parator tool and choose from the broad selection of possible comparisons there.

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The E-M10 II was launched at a markedly lower price (by 33 percent) than the D7100, which puts it into a different market segment. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The size of the imaging sensor is a crucial determinant of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have richer color depth than smaller pixels in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Olympus E-M10 II features a Four Thirds sensor and the Nikon D7100 an APS-C sensor. The sensor area in the D7100 is 63 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.5. The sensor in the E-M10 II has a native 4:3 aspect ratio, while the one in the D7100 offers a 3:2 aspect.

With 24MP, the D7100 offers a higher resolution than the E-M10 II (15.9MP), but the D7100 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.76μm for the E-M10 II) due to its larger sensor. However, the E-M10 II is a much more recent model (by 2 years and 6 months) than the D7100, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). Of the two cameras under consideration, the D7100 has a markedly higher DXO score than the E-M10 II (overall score 10 points higher), which will translate into better image quality. The advantage is based on 1.1 bits higher color depth, 1.2 EV in additional dynamic range, and 0.6 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.

Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (1080/60p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the E-M10 II has an electronic viewfinder (2360k dots), while the D7100 has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The table below summarizes some of the other core capabilities of the Olympus E-M10 II and Nikon D7100 in connection with corresponding information for a sample of similar cameras. The full specs-sheets can be found in the camera manual or, for example, in the dpreview camera hub.

Both the E-M10 II and the D7100 have been discontinued, but can regularly be found used on ebay. The D7100 was replaced by the Nikon D7200, while the E-M10 II was followed by the Olympus E-M10 III.

Summary

So what is the bottom line? Is there a clear favorite between the Olympus E-M10 II and the Olympus E-M10 II? The listing below highlights the relative strengths of the two models.

Advantages of the Olympus OM-D E-M10 Mark II:

• More framing info: Has an electronic viewfinder that displays shooting data.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Faster burst: Shoots at higher frequency (8 vs 6 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (120x83mm vs 136x107mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 375g or 49 percent) and hence easier to carry around.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• Sharper images: Has hand-shake reducing image stabilization build-in.
• More affordable: Was introduced into a lower priced category (33 percent cheaper at launch).
• More modern: Reflects 2 years and 6 months of technical progress since the D7100 launch.

Reasons to prefer the Nikon D7100:

• More detail: Has more megapixels (24 vs 15.9MP), which boosts linear resolution by 25%.
• Better image quality: Scores markedly higher (10 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.1 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (1.2 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (0.6 stops ISO advantage).
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Easier setting verification: Has a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1229k vs 1040k dots).
• Faster shutter: Has higher mechanical shutter speed (8000/sec vs 4000/sec) to freeze action.
• Longer lasting: Gets more shots (950 versus 320) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• More heavily discounted: Has been around for much longer (launched in February 2013).

If the count of individual advantages (bullet points above) is taken as a guide, the D7100 emerges as the winner of the match-up (13 : 10 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs.

In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains incomplete and does no justice, for example, to the way the E-M10 II or the D7100 handle or perform in practice. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate. This is where reviews by experts come in. The adjacent table relays the overall verdicts of several of the most popular camera review sites. The detailed reviews can be accessed, respectively, on the websites of cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.

Care should be taken when interpreting the review scores above, though. The assessments were made in relation to similar cameras of the same technological generation. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.

Other comparisons

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