Olympus OM-D E-M1 vs Nikon D7100 vs Sony A7

December 16, 2013

Lion male and female in the safari with three cameras at the bottom

In this article I will compare the Olympus OM-D E-M1, a Micro Four Thirds camera, versus Nikon D7100 (APS-C DSLR) and Sony A7, a Full frame E-mount mirrorless camera. I; personally think that all three are excellent and unique cameras, and all of them are super capable cameras, which were designed to fully satisfy the demands of the enthusiast and even professional photographers — depends on your specific needs of course.

Price Comparison

Before we start talking and comparing those three excellent digital cameras, let’s first take a look at the prices to see whether or not anyone of those cameras falls into your current budget.

Olympus OM-D E-M1: ~$1400 (body)
Nikon D7100: ~$1100 (body)
Sony A7: ~$1700

* update as of 12/15/2013 via Amazon.com, rounded up – visit Amazon.com for updated pricing.

All three cameras cost above $1000. The difference in price is quite significant, with the D7100 being the cheapest, E-M1 costs around $300 more than the D7100 and Sony A7 is the most expensive one, costs $300 more than the E-M1.

When you come to think about it and if you already plan to pay around $1400 for a high-end mirrorless camera, paying extra $300 for a full frame compact system camera seems very tempting. Of course you shouldn’t forget that you also need to buy a lens(es) if you don’t already have one for the specific camera you buy or upgrade to.

If you are starting blank and don’t have any compatible lenses, this comparison will give you all the important details about the key differences between those three cameras. You will get to understand whether or not the new Sony Alpha A7 worth buying over the cheaper E-M1, or whether or not you should prefer buying a DSLR instead of a Compact System Camera, full frame or not.

All those three cameras are aimed for the enthusiast and passionate photographer who want to make the best out of his creative skills and enhance his experience with his camera, make it more enjoyable to more interesting to explore the world of photography using an advanced tool.

New Range of Full Frame E-mount Lenses

Worth mentioning that with the new A7/A7R full frame ILC, Sony introduced a new range of Full Frame E-mount lenses — and five brand new premium lenses to match the size and performance of the new sensor. This include a Carl Zeiss Sonnar T* 35mm f/2.8, Carl Zeiss Sonnar T* 55mm f/1.8, Sony 28-70mm f/3.5-5.6 OSS, Sony G 70-200mm f/4 OSS and G 70-200mm f/2.8 G SSM II lenses.

Alongside these new lenses, Sony also released two new adapters, the LA-EA4 and LA-EA3 for E-mount lenses to mount A-mount lenses. The first one supports autofocus, the latter does not.

No doubt that with this released of those excellent lenses that Sony aimed really high and looking to conquer the upper-end section of the enthusiast and semi-pro category. That still not a large range to convince professional to make the switch I assume, but not doubt that Sony is on the right path as its competitors don’t have full frame cameras to upgrade to.

Next, I will continue to a short introduction to each camera — this will give you a good overview of the key features and capabilities of each camera. Later on we’ll move on to the comparison itself.

Sony A7 (α7 / Alpha 7)

Sony A7The Sony A7 was announced on October 16, 2013 — It’s Sony’s and a World’s first full frame mirrorless Interchangeable camera. The A7 was announced alongside the A7R which carries a different sensor and AF system.

The A7 body is built with magnesium alloy frame with polycarbonate front panel and it’s weather sealed (dust and moisture). The A7 features a 24 megapixels Full Frame CMOS sensor with an optical low-pass filter, compare to the more expensive A7R model that lacks the OLPF. In fact, the A7 is also the lightest interchangeable lens full-frame camera.

The A7 was designed from the ground up for enthusiast and semi-pros alike. As the digital camera’s market continues to shrink in favor of mobile phone cameras, there is a great need to acquire and keep the enthusiast crowd that can appreciate and takes advantage of those advanced photographic tools. The competition won’t get easier in time and Sony puts a lot of effort in order to attract new customers from the other camps to join its forces.

Sony A7, Canon 6D and Nikon D610 side by side

Sony A7 (left), Canon EOS 6D (middle), Nikon D610 (right) -- click to view enlarged on camerasize.com

As you can see from the above image, the A7 is significantly smaller than the Canon EOS 6D and Nikon D610 / D600, all three are full frame interchangeable lens cameras. The 6D and D610 are DSLR cameras equipped with a reflex mirror, whether the A7 is a mirrorless interchangeable lens camera that lacks the internal reflex mirror.

The A7 carries a rather straight and simplistic design, rather than the more rounded design that we use to see with DSLR cameras, and quite reminds me the design of Sony NEX cameras. Worth mentioning that Sony has merged the NEX camera brand under the Alpha brand name, which means that future NEX cameras will have the prefix Alpha (e.g. Alpha NEX-6).

Among the new key features are a true-to-life 2.4 Million dot OLED viewfinder, WiFi / NFC wireless capabilities, fast Hybrid AF with phase-detection, newly developed Eye AF control (eye-detection that can prioritize a single pupil), lots of shooting controls and dials gaining quick access to frequently used camera settings, 3″ 1.23M dot tilting LCD, newly developed BIONZ X image processor, diffraction correction technology, 1080p60 video recording and even supports the ability to download PlayMemories apps to the camera to extend its capabilities.

The A7 was designed to compete against other advanced APS-C And Full Frame DSLR cameras while offering super advanced and fast AF performance with 117 on-sensor phase-detection AF points and 25 contrast-detection AF points, and focus on those capabilities that enthusiast and semi-professionals care about most.

Whether those features and camera capabilities will convince photographers to move from Canon and Nikon to use one of these two exciting new cameras, only time will tell. What we know is that Sony doesn’t stop innovating and the Alpha 7 is certainly a big step in this direction.

The A7 also gets the VG-C1EM compatible vertical grip which can hold two batteries for longer shooting. The A7 battery grip is also weather against dust and moisture as the camera body.

I already mentioned it but it’s worth mentioning it again. The A7 and A7R are compatible with Sony’s new FE-series lenses, which were designed from the ground up for full-frame sensors. If you currently own E-mount lenses, those lenses are compatible with the A7 mount, but the image circle won’t cover the whole area of the sensor.

You can see the complete list of the Alpha NEX lenses here on Sony.com website. Those new full frame lenses are marked with the ‘FE’ letters. Among those are professional-grade three Carl Zeiss lenses (i.e. 55mm f1.8, 24-70 f4 and 35mm f2.8).

Olympus OM-D E-M1

Olympus OM-D E-M1 MFT cameraThe Olympus OM-D E-M1 was announced on September 10, 2013. The E-M1 is Micro Four Thirds camera and it’s compatible with both Zuiko Four Thirds lenses using the MMF-3 adapter. The camera will therefore designed to attract Four Thirds shooters to move to the Micro Four Thirds standard.

The support for Four Thirds lenses comes with a feature that automatically selects either 37-point phase-detect AF which is optimized for Four Thirds lenses, or use the traditional 81-point contrast-detect AF system which is optimized for MFT lenses (aka Dual Fast AF).

The Olympus EM1 design closely resembles that of the E-M5, but it features a much larger grip that actually makes it look more like a DSLR than a compact system camera by design. The E-M1 is the most expensive and advanced model. It features a newly developed TruePic VII image processor, new sensor, more advanced AF system (81 AF points vs 35 AF points), higher resolution rear LCD, larger EVF with much higher resolution, faster shutter speed (1/8000 Sec vs 1/4000 Sec), faster burst — even the 5-axis IS system has been improved.

For a complete list of the differences between the E-M1 and E-M5 I recommend reading my Olympus E-M1 vs E-M5 comparison article.

Olympus didn’t opt for a full frame camera and therefore did its best to come up with a highly-capable and fully-featured MFT camera. The eye-level viewfinder is certainly one of the features that enthusiasts and professional photographers care about, and it’s nice to see Olympus giving this feature a great deal of attention. In fact, this viewfinder is as big as an optical viewfinder which you can find on a full-frame DSLR camera.

The E-M1 has built-in WiFi connectivity which you can use with Olympus OI.Share app to gain full control over the camera’s shutter speed, aperture, ISO or use the Live Bulb shooting, and easily share your gorgeous photos with others using you mobile phone. The E-M1 can also take advantage of the on-board GPS on your phone to obtain location information and automatically geotag your images.

The E-M1 is a weather-resistant camera built around the magnesium alloy body which was built with lots of customization options and certainly closing the gap that MFT cameras have compared to DSLR cameras. It has won dpreview Gold Award and gained lots of positive reviews all across professional camera review websites.

So if you are upgrading from a Four Thirds camera (e.g. Olympus E-5) or searching for a high-end micro four thirds camera, the E-M1 is probably among the most attractive offering on the market right now.

Nikon D7100

Nikon D7100 cameraAnnounced on February 21, 2013 — For many people, the Nikon D7100 needs no introduction. Regardless of its model name, the D7100 is not a replacement to the D7000 that was announced on September 15, 2012 — but rather a new model that joins Nikon’s DSLR lineup.

The Nikon D7100 is one of the most attractive enthusiast DSLR camera on the market right now. Already won dpreview’s Gold Award, the D7100 was designed to offer photographers a super advanced photographic tool that will take their skills to a new level without posing any hard limitations.

The D7100 features a newly designed 24.1 megapixel APS-C / DX-format sensor. Regardless of the very high resolution, the D7100 was designed to offer superb low-light performance as well as very precise autofocus and light metering system.

This performance is improved over the D7000, but that doesn’t take much of the D7000 that has a stellar performance in those three categories. The D7100 inherits the AF system from the D300s with 51 focus points, 15 of them are cross-type. The camera also uses Nikon’s 2016-pixel RGB light metering sensor which provides very accurate metering, even when used in complicated lighting scenarios.

The D7100 was designed to be an excellent stills camera as it is for shooting videos. You can shoot full HD videos at 60i, 24p and 30p (NTSC) and 60p and 30p in 720 HD resolution. It’s still behind some new interchangeable lens cameras that offer 1080p60 (60 fps progressive frames).

The Nikon D7100 has a magnesium alloy body with weather sealing to protect the camera against dust and moisture.

The D7100 is the cheapest camera in the group, but no doubt that for its price it will attract both amateurs and enthusiasts alike, those that might prefer to spend more on a higher quality / second Nikkor lens instead of spending more on the camera body.

If you are searching a a DSLR camera that can deliver outstanding image quality for both stills and video, weather-sealed, with fast burst and excellent AF performance, the Nikon D7100 might be your best bet.

Mirrorless vs DSLR

The first obstacle that people are stumbling upon when buying a new interchangeable lens camera is whether to buy a DSLR or a Mirrorless interchangeable lens camera. No doubt that mirrorless cameras have come a long way and almost completely minimized the gap towards DSLR cameras.

Some people prefer buying a DSLR for many reasons, among those:

  • Optical viewfinder (e.g. No lag)
  • Larger range of professional accessories
  • Large selection of lenses
  • Easier to sell as second-hand
  • Phase-detection AF (although some mirrorless cameras already implemented this feature)
  • Better battery life
  • A large sensor (compared to Micro Four Thirds)

Mirrorless cameras have the following advantages:

  • Relatively smaller size and weight less
  • Less shutter noise and camera shake to to shutter press
  • Easier to clean the sensor
  • Very fast burst speed
  • Advanced viewfinder functionality with information overlay and the ability to get better visibility in low-light by increasing the brightness, Live preview of the scene and instant image review when pressing the shutter button on the viewfinder’s LCD
  • More AF points (on selected models)
  • Very fast AF performance that is at least on par with what you get with DSLR cameras (on selected models)
  • More weather-sealed cameras that are quite affordable in comparison to DSLRs

Now that we also have a consumer-level full frame mirrorless camera, we can omit the full-frame camera availability. Before the A7 came out, you could have bought the Leica M, but obviously this is not a camera that every photographer can afford.

I can understand the reasons why some photographers still opt for a DSLR camera. There are many cheap entry-level DSLR cameras like the Sony A3000, Canon EOS T3i, Nikon D3100, Canon EOS Rebel SL1 — all are very affordable sub $600 DSLR cameras. You get high quality photos and great performance from every one of them. For some people that’s more than enough and not anyone is convinced by the new features which are introduced with each new model.

The E-M1, D7100 and A7 — all are aimed towards the enthusiast photographer and for semi-pro photographers that already know their specific needs. Having said that, it doesn’t say that making a decision between the two is easy. In fact, some people are spending hours and even days reading reviews, comparing features and over-analyzing the high ISO performance just to make sure that they are buying the camera that best fits their needs.

In this comparison we have three interchangeable lens cameras, but in fact each one is unique in its own right. In order to make a smart buying decision, you need to understand the differences between those three cameras and eliminate those cameras that either miss specific feature that you need, or those that perform less under a specific category that you need it to perform well for your specific shooting habits and professional needs.

So now we head on to the comparison itself, where you get to fully understand and compare the three camera’s capabilities and design features head-to-head. I’m pretty sure that after you fully read and understand the differences, you will be able to make a much more knowledgeable buying decision and pick up a camera that you will be fully satisfied with without any regret afterwards.

OM-D E-M1 vs D7100 vs A7

In this section I will compare the three cameras side by side. In the below specs side by side comparison table you can clearly see and comprehend the differences between those three cameras. I am also adding some side notes to help out for those that lack the technical knowledge and also some cons and pros that are related to a specific spec when appropriate.

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Let’s sum up the cons and pros of each camera:

Olympus OM-D E-M1

  • Full magnesium alloy body and outer metal
  • Dust, Splash and Freezeproof
  • Large lens selection
  • 5-axis in-body image stabilization
  • Automatic AF optimization based on lens (four thirds or micro four thirds)
  • Highest EVF resolution
  • Largest viewfinder
  • Fastest burst
  • 60 sec shutter speed
  • Small flash included in the box
  • Fastest X Sync speed
  • Relatively small size
  • Built-in WiFi (but no NFC)
  • 25600 maximum ISO sensitivity (same as A7)
  • Tilting LCD
  • No pop-up flash
  • Second lowest battery life, slightly better than the A7
  • Lowest sensor resolution in the group
  • Smallest sensor pixels among the three cameras
  • Lowest LCD resolution (1037K)
  • Least impressive video functionality and frame rate selection, no 24p
  • No headphone jack
  • No pop-up flash

Nikon D7100

  • Top LCD display
  • Largest rear LCD
  • Optical viewfinder
  • Largest lens selection
  • Dual SD card
  • Pop-up flash
  • Great video features (frame rates, and both mic and headphone jack)
  • By far the best battery life in the group
  • The cheapest
  • Good weather sealing
  • Slowest flash x sync (same as A7)
  • Highest resolution (same as A7)
  • Second largest pixel size
  • Second largest sensor
  • Second highest phase-detection AF points
  • Second highest screen resolution
  • Second fastest burst
  • No 60p
  • Least durable body (top / rear polycarbonate)
  • Largest and heaviest in the group
  • Lowest maximum ISO sensitivity
  • Fixed rear LCD
  • Smallest viewfinder
  • No built-in wireless

Sony Alpha 7

  • Smallest in the group, amazing considering it’s a full frame camera
  • Full Frame sensor
  • Highest amount of customizatable buttons
  • Lightest in the group
  • Largest sensor pixels
  • Hybrid AF + highest amount of phase-detection AF points
  • Highest resolution rear LCD (slightly higher than D7100 though)
  • Very high EVF resolution + OLED technology
  • WiFi + NFC
  • Installable apps
  • Second most durable body
  • Tilting LCD
  • Second largest viewfinder
  • Highest maximum ISO (same as E-M1)
  • Headphone jack, same as E-M1
  • Highest resolution (same as D7100)
  • Good weather sealing
  • Slowest Flash X sync speed (same as D7100)
  • Slowest burst
  • No pop up flash
  • Lowest battery life
  • The most expensive one

You can see from the above cons and pros list that each camera has its advantage and disadvantages compared to the other two. Understanding the strength and weaknesses of each one will help you put out the cameras that doesn’t have those features that you are looking in your next camera.

Image Quality Comparison

In this section I will share with you my high ISO comparison conclusions using imaging resource comparometer.

E-M1 vs D7100

  • ISO 100 — Both cameras produce very clean images as expected. The D7100 image size is noticeable, however the E-M1 image look sharper and textures look much better in my opinion on the E-M1. Also the E-M1 image color looks more natural compare to the more warmer D7100 color in my observation. I am really impressed with the JPEG IQ of the E-M1. I assume that E-M1 applies stronger in-camera sharpening compare to the more preservative approach of the D7100. Having said that, the texture details is not something that you get from in-camera sharpening but rather than a better sensor and/or optics. Advantage: E-M1 (sharpness, texture, color reproduction)
  • ISO 200 — same results as ISO 100. Advantage: E-M1
  • ISO 400 — E-M1 looks cleaner image noise wise, but overall excellent performance from both cameras. EM1 stills enjoys the advantages that I mentioned in ISO 100. Advantage E-M1 (slightly less noise)
  • ISO 800 — noise is visibly more visible on both cameras with a slight edge for the E-M1. Advantage: E-M1 (slightly less noise)
  • ISO 1600 — E-M1 continues to impress with relatively very clean image at ISO 1600. D7100 looks worse, start losing fine details and image is much more visible when viewing in 100% scale. Advantage: E-M1 (cleaner image, E-M1 impressive results)
  • ISO 3200 — A big difference between the two. The E-M1 is to my surprise amazingly clean for that ISO sensitivity. The D7100 suffers from a lot of image noise including chroma noise patterns in many parts of the image and the image overall is very noisy. For best result I would should with the D7100 under ISO 3200. Very impressive results from the E-M1!
    Advantage: E-M1 (much cleaner image)
  • ISO 6400 — A big difference between the E-M1 ISO3200 and ISO6400. The E-M1 ISO6400 is much noisier but still very usable for small prints and for the web.

No doubt here, the Olympus OM-D E-M1 high ISO performance is much better than the Nikon D7100. The D7100 has an excellent IQ in low ISO, but as you climb up the ISO scale you can clearly see the advantage of the E-M1. I would say a 1.5EV advantage in favor of the E-M1, which certainly makes this camera better for low-light photography.

DxOMark for E-M1:

  • Overall score: 73
  • Color depth: 23 bits
  • Dynamic range: 12.7 Evs
  • Low-light ISO: 757 ISO

DxoMark for D7100:

  • Overall score: 83
  • Color depth: 24.2 bits
  • Dynamic range: 13.7 Evs
  • Low-light ISO: 1256 ISO

These results from DxOMark comes as a mixed bag for me, because what I’ve seen in my observation doesn’t stand hand-in-hand with what DxOMark score show, especially in the high ISO performance. What do you think?

E-M1 vs Alpha A7

  • ISO 100 — We can clearly see the advantage of having a full frame sensor (larger pixels). The A7 IQ is just superb. Both cameras produce very high IQ, however the A7 outperform the E-M1 with higher dynamic range which is visible, more details and sharper results. As you think that it’s hard to beat the E-M1 IQ, then comes the A7 and shows us one of the advantages of shooting with a full frame sensor, and the Sony FF certainly doesn’t disappoint — better than that, I was blown away with the IQ.. Excellent work Sony! – Advantage: A7 (sharpness, color reproduction, contrast and texture details)
  • ISO 200 — same results as ISO 100 more or less. Advantage: A7
  • ISO 400 — small amount of noise in dark areas in the E-M1 images, but nothing to worry about. A7 very clean image, and it’s like viewing ISO 100 images. Advantage: A7
  • ISO 800 — noise is visible in both cameras, but certainly much more visible on the E-M1. Well guys, that’s what full frame cameras are all about, IQ – and the A7 high ISO performance so far is just astonishing, but expected. Advantage: A7
  • ISO 1600 — E-M1 ISO 1600 is much more noisy compare to ISO800, a clear advantage for the A7 with relatively very clean image!! – Advantage: A7
  • ISO 3200 — large drop in the dynamic range of the E-M1 images and more noise. This is also where we can see a more significant drop with the A7 as well but the image is still relatively very clean and very usable too. Advantage: A7
  • ISO 6400— kind of the end of the road for the E-M1, and wouldn’t shout ISO 6400 unless there isn’t any other way to capture the shot. The A7 also suffers from lots of noise and I personally recommend shooting up to ISO 3200 for optimal IQ. Advantage: A7

I was very impressed with the E-M1 high ISO performance, but after seeing the A7, it makes the E-M1 look much less attractive. Having said that, it doesn’t take much of the E-M1 high ISO performance in its own right.

The Sony Alpha A7 can certainly open up more opportunities for low-light shooting without flash. Just mount a fast prime lens on the A7 and you can a superb camera for low-light scenarios.

DxoMark for Sony A7:

  • Overall score: 90
  • Color depth: 24.8 bits
  • Dynamic range: 14.2 Evs
  • Low-light ISO: 2248 ISO

This time the DxOMark does reflect what I’ve seen with my own eyes when comparing the A7 images versus the E-M1.

Let’s take a look at some sample videos shall we..

Sony A7 sample video:

Olympus OM-D E-M5 sample video:

Nikon D7100 sample video:


Which one looks better in your opinion?


I have to admit, I was very impressed with the Sony A7 and there is probably very little not to like about this camera. It’s a stellar performer up to ISO 3200 and outstanding all-around performer regardless of being a mirrorless camera. In fact, I am always amazed by how small this camera is compared to the Canon 5D Mark III and Nikon D600.

Right now there aren’t many FE lenses available and the selection will grow in time. Those three Carl Zeiss lenses don’t come cheap and the 28-70mm is the only affordable lens in the lineup and sold as a kit lens for extra $300. That’s something that you consider as well, unless you intend to buy the adapter and use some of your existing A mount lenses. The Sony Vario-Tessar T* FE 24-700mm f/4 ZA OSS lens costs $1200, and obviously some photographer might not be able to afford buying one of those professional grade lenses.

All in all, I think that the A7 is very well priced and is a excellent alternative for a full frame DSLR, for those who need and can afford buying one of Sony’s excellent FE lenses for the A7/A7R. The A7 isn’t intended for fast action shooters, but other than that is in my opinion, one of the most impressive ILC cameras on the market and opens the Full frame world for mirrorless fans, enthusiast and pros alike ,whether it for stills or video shooting.

What I like about the OM-D E-M1 is its weather sealing and durable construction, superb image quality — especially considering the fact that it uses a micro four thirds and was able (in my observation) to outperform the D7100 APS-C sensor. It has an excellent viewfinder (largest in the group), built-in IS and provide a wide range of features and buttons which put this camera as a great DSLR alternative, and a superb offering for Olympus photographers who are planning to upgrade from the E-5.

The D7100 is the cheapest camera in the group, and fell short in the high ISO performance, but had an excellent low ISO performance. What I like about the D7100 is its build quality and ergonomics, especially useful for people with large hands and those who intend to mount extra accessories for the camera (e.g. Flash). It has a very good burst speed, dual SD card slot, optical viewfinder and superb AF performance which you have to use it in order to appreciate it. When I first shot with the D7100 I thought that the camera had a focus problem, because I just didn’t notice that it focuses — it did is SO FAST.

The D7100 however is less impressive when it comes to video shooting, but I think that those who opt for the D7100 probably care less about the video quality, and focus on the stills qualities of this camera. Buying the D7100 will give you an excellent body and the option to also spend more on a higher quality Nikkor lens or a secondary lens. I personally prefer this option because I can buy special lenses (e.g. Fisheye, ultra wide-angle, fast primes) that will help me become more creative with my camera, and for me it’s more important than some of the features that both the A7 and E-M1 offer. Obviously that’s my decision, you might decide otherwise. The D7100 is one of the most attractive cameras for enthusiasts on a budget and those who plan to upgrade from Nikon’s entry-level cameras.

The superb interchangeable lens cameras, each one with its own cons and pros as you’ve read in this comparison. There isn’t any winner, as all three have their cons and pros in different categories, and also in terms of pricing. I would say that I was more impressed with the A7 in general, and if I could afford it (And one of its Zeiss lenses) I would buy it over the D7100 and E-M1,

Which one you prefer? — Share your opinion or/and questions in the comment section below.

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