Small mirrorless cameras are more popular than ever, but this also means that buyers can be a little perplexed by the overwhelming choice. Two of the newest models to the market are Olympus’ E-M5 MkIII and Nikon’s Z 50 – both models were launched in October and offer a massive range of features in travel-friendly, compact bodies.
Both cameras share a number of features, but there’s also a huge amount that separates the models too. We’re drilling down deep into the specifications sheets of the two cameras to help you make an informed buying decision so you can pick the right camera for your personal needs…

Design and build:
So let’s start with the Olympus E-M5 MkIII and, as the name suggests, this is the third incarnation of the popular camera from the OM-D series of mirrorless models. Built around the standard Olympus the E-M5 MkIII Four-Thirds sensor and Micro Four-Thirds lens mount, the MkIII sees a jump in resolution over the older MkII model (20-megapixels v 16-megapixels). Because the MkII was launched way back in 2015, this series was well overdue an update and Olympus look to have come good, delivering a host of new features, which major on speed and video benefits. The MkIII body is weather sealed, ensuring the camera is suitable for use by professional photographers and carries the 2x crop factor from the Micro Four-Thirds lens mount that effectively doubles the focal length of your lens, meaning a 50mm becomes 100mm, a 300mm becomes a 600mm and so on. This is great for photographers who would like to shoot wildlife or sports imagery because you can get up close using a compact lightweight lens that’s likely to cost a fraction of the cost from a full-frame DSLR brand. What’s more, because the Olympus system has been around a while, there is a huge amount of lens choice to pick from, both via Olympus themselves or thanks to a third-party lens manufacturers like Sigma or Samyang.

Meanwhile, the Nikon Z 50 is a first-generation camera and the brand’s first-ever APS-C mirrorless and follows in the footsteps of Nikon’s first full-frame mirrorless cameras; the Z 6 / Z 7. Built around a 20-megapixel APS-C sensor which generates a 1.5x crop factor, the weather-sealed Z 50 uses the Z lens mount, meaning for now there are just two DX Z lenses (the DX 16-50mm f/3.5-6.3 and DX 5-250mm f/4.5-6.3). However, existing Nikon shooters will be pleased to hear they can use their regular F mount lenses on the Z 50 via an adaptor.
Both cameras are small, very small! The E-M5 MkIII weighs just 414g (including battery and memory card) and measures only 125x85x50mm, while the Nikon Z 50 tips the scales only a slight bit heavier at 450g (including battery and memory card) and is more or less the same size (127x94x60mm). Both camera bodies (without the lenses) can fit in your back pocket and these lightweight credentials makes both cameras very suitable for travel photography, when space may be at a premium. While both cameras offer a 2360k dot Electronic viewfinder, there’s a difference when it comes to LCD design as while the Z 50 features a 3.2-inch touch-sensitive tilting LCD, the E-M5 MkIII offers a 3-inch touch-sensitive vari-angle LCD, which is more useful when setting up awkward high/low compositions. Interestingly, the Z 50 features magnify and Display buttons within its screen, which saves space on the camera body. Both cameras have excellent button layouts, meaning all the important features fall easily to hand. Both cameras also record stills and video to a single SD card slot, too.
The biggest differences in terms of features comes in the areas of focusing and speed. Both cameras offer impressive autofocus systems, but the Z 50 offers 209 AF points, more than the 121-AF points from the E-M5 MkIII. However, the Olympus strikes back when it comes to burst speed offering an epic maximum burst rate of 30 frames per second. Of course, the Z 50 offers 11 frames per second, which is still very decent and should be enough for everyday action photography, but if you really want to major in sports or wildlife, the E-M5 MkIII’s 30FPS is hard to ignore. The other huge difference is that there’s no IBIS (In Body Image Stabilisation) in the Z 50, while the E-M5 MkIII offers Olympus’ acclaimed Dual IS system, affording up to 6.5-stops of compensation, which could prove the difference when shooting handheld in low light conditions.

Image quality:
With very similar resolutions, the two cameras are more than capable of producing professional-level imagery. Both offer RAW file formats and decent max file sizes (5184 x 3888 pixels for the Olympus and 5568 x 3712 pixels for the Nikon) – this means both cameras can easily make prints of up to A3 in size and have tolerance to crop in on images without overly compromising image quality.
Also, both cameras can cut it when it comes to low light performance, although the Nikon has the higher ISO ceiling; (51,200 compared to 25600). For those who wish to get creative in-camera, the E-M5 MkIII has a huge amount of Art filters, while the Z 50 also provides plenty of ‘Effect’ filters; including Pop, Selective Colour, Toy camera and Miniature effect.

Video:
Many photographers eye up these sorts of cameras will want decent video specifications along with excellent stills performance and there may even be Vloggers who place both cameras on their shortlists. Luckily, each model comes good, offering decent quality footage. In fact, both cameras can offer ultra high-quality 4K footage at 30p – in fact the Olympus can shoot Cinema 4K at 25p. For those who don’t need the better quality, or don’t want the massive file sizes, each model shoot Full HD at 60p and can capture 120p in Full HD too, meaning that epic slow motion footage can be captured at a decent resolution.
Despite the small size of the cameras, both models feature a jack for an external microphone so enhanced audio can be captured. Because the E-M5 MkIII and Z 50 are so light, they will be easy to use with one-handed gimbal systems like the DJI Ronin SC, enabling film-makers to increase their production values.

Additional features and verdict:
As we’ve explained, the two cameras are closely matched, but there still yet more differences. The E-M5 MkIII features a high-resolution mode that shoots and merges multiple files into one 50-megapixel frame. Meanwhile the Z 50 features a built-in pop-up flash – useful for providing fill-in light for close up subjects during low light conditions. Alternatively, the E-M5 MkIII features a faster maximum shutter speed (1/8000sec compared to 1/4000sec on the Z 50) and boasts a Focus Stacking mode, while the Z 50 can offer a slightly higher battery capacity, giving 320 shots on a single charge compared to 310 from the Olympus.

Ultimately, both the E-M5 MkIII and Nikon Z 50 are excellent cameras, merging compact and lightweight dimensions with decent resolution, rapid speed and well thought-out ergonomics. Of course, the E-M5 MkIII is the third incarnation of the camera, so has been refined to make it a highly intuitive tool. Despite being a first generation model, the Z 50 proves a competitive option that is sure to improve, either via firmware updates or in the next incarnation.
Nikon photographers who already have a bag full of F glass are more likely to be tempted by the Z 50, thanks to that lens adaptor that will afford photographers a wider selection of lenses. Newcomers to either system may prefer that epic 30 frames per second burst rate from the Olympus and wildlife shooters are also more likely to favour the Olympus thanks to that 2x crop factor. Both cameras are great buys and are sure to reward whoever buys them with years’ worth of great imagery and video.