The 2020 Coronavirus outbreak prompted much pondering on the nature of things. However Micro Four-Thirds (henceforth M43) has always attracted peculiarly fecund speculation about its nature and niche in the photographic ecosystem. What is it? Why is it here? And what does its future hold?

As a religion, the primary doctrine of M43 is portability. Portability and image quality. The two primary doctrines of M43 are a specific ratio of size:performance – good enough to be useable; small enough to pocket, but big enough to grip – oh, and video. Thus the three primary doctrines of M43.

And thereby the demise of Four Thirds. 4:3 is a nasty format: it’s sole advantage is smaller image circles than 35mm or 16-9. A square format is even more amenable to small optics, but who wants that? Four-Thirds made no sense until it became Micro.

Key to M43’s currently carved-in market position was (is) the calibre of product development by Olympus and Panasonic. If the spirit of M43 is pure Olympus, the muscle, brain and connective tissue is Panasonic. 

Lotus once manufactured agile, rewarding, jewel-like cars meticulously designed according to the aesthetic of ‘strictly no more than necessary’. Driving a Lotus makes a direct connection to the road that is among the most rewarding motoring experiences. Using an Olympus camera of any vintage has a similar vibe. But a beguiling ethos isn’t enough to spawn and nurture a new format – Panasonic did that.

Despite meagre photographic pedigree, Panasonic revealed a latent talent for capturing the moment: the GH4 was the right tool at the right time. Where would M43 be today without the GH4 and the support of a burgeoning tribe of film-makers? But its traction among videographers was no fluke: it was unreasonably well designed. It did everything it set out do – reliably, proficiently and ergonomically. Canon and Nikon users regularly debate the arcana of user interfaces and the ease with which each permits man and machine to achieve unity. With justification, they watched Sony’s fumbling sophomore efforts that – generations down the line – are only just beginning to mature. It’s therefore surprising that the GH Series – and its properly thought-through system accessories – got so much right so quickly, and that the current Panasonic G9 costs so little, does so much, and feels so right.

Panasonic proved the GH4 wasn’t a one-off: its successors developed its strengths in harmony with user’s needs, building brand loyalty. The collaboration with Leica was a perfect fit but the biggest surprise – still not given wide enough credence – has been the excellence of Panasonic’s own lenses.

The collaborative nature of the relationship with Olympus also benefited M43 users: Olympus glass, which continues its heritage of excellence, not only mounts and autofocuses on Panasonic bodies, it often works equally well. Based on the security of this twin platform, Laowa, Sigma, Rokinon and Voigtlander have contributed to what is now a diverse optical ecosystem. In turn, this gave birth to the Speedbooster phenomenon, turbocharging demand and diversifying options for adapted lenses.

Lest we forget, Olympus M43 bodies are also beautifully designed and made.

M43 currently stands astride a well founded position: appealing enough to have a market among serious amateurs, and serious enough to appeal to professionals. Although not an endgame solution for demanding applications, it has nestled into many photographers hearts as a reliable complementary system to their main ‘do-it-all’ rig. And that’s because there are fundamental limits to M43’s capability. So what is M43, and what is it not?

Size is the enemy of excellence. That’s why wee hench things are cool: pocket battleships, Beretta, Ant Man. But a good big’un still beats a good littl’un. Starting out with a small 4:3 sensor creates a domino snake of technical challenges and hard limits. For instance, M43 images will always be noisier than full frame – which creates a greater need for light gathering, which mandates larger and heavier lenses. M43 images have inherently greater depth of field than full frame, which, for creative control, mandates large, heavy, fast lenses. However, M43 folk want tiny lenses. Inevitably these are slow and suffer from vignetting, which is not painless to correct on M43 – because of the image noise.

The smaller the sensor, the harder it is to design effective wide angle lenses without aberrations. Development of reference-grade wide glass is about 25 years behind full-frame in terms of deliverable results. What I mean by that is that if you need to shoot sub-20mm equivalent focal lengths, your best options still have soft corners and chromatic and spherical aberration – like working with ultrawides from the 1990s.

M43’s approach in general is to design optics for resolution and fix the rest in post. While it makes sense to shift the heavy lifting into the digital domain – leveraging processing power to reduce size and weight – at pixel-level, M43 files have a slightly ‘worked-on’ plasticky look, especially in the corners where the lens profiles have to work doubly hard to correct geometric and other aberrations while adjusting luminance to compensate for vignetting. And all because Four Thirds only succeeds when it’s Micro.

If creativity thrives on limitations, M43 is a case in point. Metabones and Coastal Optics must be singled out here for bringing the yang to M43’s yin. The ability to adapt existing lenses is a powerful enough lever to elevate a system alone, but the Speedbooster reduces aberrations, gathers more light, and restores half the control over DoF lost by the smaller sensor. Their role in the survival of M43 shouldn’t be underestimated.

The diverse adaptability permits almost any lens made to be mounted on M43, with or without enhancing lenses. They are many viable and inexpensive ways to obtain tilt and shift movements deploying the relatively oversized image circle of 35mm optics. Coming from 35mm, the little sensor behaves like a 2x teleconverter, which makes M43 under-rated for many kinds of wildlife photography (see caveats below).

So, the format excels at travel photography and any situation where space and mass are at a premium. Ditto applications where you need to be a long way from your subject. But, little sensor – are 20Mp files big enough? For many jobs, no. It’s not just about the capture size: it’s about our ability to crop and manipulate and still deliver a large image. However, that all changed with the Panasonic G9’s Hi-Res mode, which first perfected pixel-shifting. For product, static macro, and most architectural, landscape and food photography, the 80MP RAW files produced by the G9 cannot be bettered by any full frame sensor that isn’t capable of similar stacking. At the time of writing, that only refers to the Panasonic’s larger sibling, the S1R.

That’s worth unpacking for a moment. The best all-round 35mm camera in 2020 is probably the Sony A7R IV at a little under £3000. But to exploit its potential requires top-flight glass commensurate with the demands of its 60.7MP sensor. Fortunately, thanks to the Zeiss collaboration and the uniformly awesome Sigma ART range, those lenses exist. Let’s say, as a bare minimum you get: Sony 16-35mm /  24-70mm / 70-200mm and two fast primes: 35mm + 85mm f1.4. That’s roughly £13,000 – or £9,000 if you opt for the Sigma versions. You may also need a macro, fast 24 and 50mm primes, and something to give you extra reach. Oh, and a backup second body. So around £20K – more if you shoot sport or wildlife for a living and demanded the dread combination of length and speed.

The Lumix G9 is £900. It’s pixel pitch is similar to the Sony’s (3.3 v 3.7 microns) but its HiRes mode only requires aberration-free coverage of an 18mm-wide sensor to deliver twenty million more pixels per capture. Mmm – shifty. Fortunately, thanks to the Leica and Olympus collaboration, and Sigma’s support of the mount system, there are several ways to resolve the sensor adequately at most focal lengths. The cost of G9 + 7-14mm / 12-35mm / 35-100mm + 17/45mm fast primes is around £4000. Adding a second body, macro, two more fast primes and a tele-zoom might take you to £7000 for the whole system.

Pros and cons?

Practicality: Sony full-frame system is double the weight and triple the cost of the G9’s. M43 tele lenses much smaller.
Speed: Sony is no better at freezing action, but offers two stops shallower DoF. Speedbooster reduces the difference to one stop at the expense of compromised autofocus. G9 has faster continuous shooting capability (20fps vs 10fps). G9 has faster maximum (1/32,000 v 1/8,000) and slower minimum (60 v 30 secs) shutter speed.
Light Gathering: Sony full frame is clearly superior
Autofocus: Sony is quicker and more consistent (576 points and phase detect v 225 points contrast detect), but the greatest difference is in low light. However Panasonic’s G9 implementation has considerably narrowed what used to be a sizeable gap. The best M43 AF systems are now not far behind Nikon and Sony.
Resolution/Sharpness: G9 is superior for static subjects (80MP v 61MP) ; significantly inferior for objects in motion (20MP v 61MP)
Image Stabilisation: Both G9 and A7R are state-of-the-art, combining in-body and lens-based compensation. However G9 is more effective (6.5 stops in body, vs 5.5 stops for the Sony).
Robustness: Both have weather-sealed magnesium alloy bodies.
System support: M43 has wider and cheaper range of lenses and accessories.
Video: G9 significantly superior in terms of compression and frame rate (60p 4K 10-bit 150MB/s vs 30p 4K 8-bit 100MB/s) but Sony continuous AF for video slightly better.
Other features: Both have silent E-shutters. Neither have inbuilt flash. A7R IV has better viewfinder (5MP v 3MP).

There are a few clear-cut cases where a full-frame system is (will be) unquestionably better: anything shot in low light, particularly moving objects. Even in good light, if you need to freeze a subject in motion at high resolution, especially if you need elite-level AF, you shouldn’t be shooting M43. For high-end sport, surfers, running chickens, and low-lit events (including the church and dancefloor phase of weddings) M43 is the wrong camera. There isn’t a perfect 15-20mm equivalent lens for M43. Also, the look obtained by shooting f1.2 lenses wide open on full frame can’t quite be replicated on M43. 

But when you have to shoot people, M43 is equally viable. When you’re spending a day physically attached to multiple cameras, M43’s portability is a blessing. It’s the king of travel photography. It’s the camera you reach for to take on holiday, with a couple of primes in a pocket. It is the camera you shoot video with – in daylight, at least. Unexpectedly, the G9 also became my first choice to shoot architecture, products, cars, food, slide copying, landscapes and pretty much anything I shoot from a tripod when high resolution is needed.

Along the way I’ve learned surprising things about M43 and 35mm lenses, to be related in other articles. The only real downer about M43 is users’ obsession with size: eulogising miniature and pancake lenses, and plastic-bodied collapsibles. With notable exceptions, these tend to be dismal performers, the novelty of which quickly fades. Nobody cares about the EXIF data. It’s the image, stupid. The upside of this gestalt is that many of the lenses that really should be sought after – pieces of work destined to become classics – are damned with faint praise. In the case of Panasonic lenses, they are hiding in plain sight: the 12-35mm f2.8 kit lens is much more than a ‘nice upgrade’ over the kit lens. Having said that, the original 14-45mm f3.5-5.6 kit lens was astonishing, and the 14-140mm f3.5-5.6 is a revelation. The 35-100mm f2.8 is undervalued and 10-25mm f1.7 is a paradigm-buster – exactly what M43 needs – but it’s large and expensive, so not what it wants.

In the long run – let’s aim for a 30 year forecast – I’m not sure M43 can survive. It’s evolutionary niche may be too small; its USP not well enough defined; its competitors too close and strong. Full-frame cameras are getting smaller and the ultimate portable imaging device – the mobile phone – is rapidly improving. Can M43 and APS-C thrive, stuck in the mid-ground without room to expand their market? Panasonic is locked in a battle it can’t lose with Sony: if the GH6, GH7 or GH8 lose their cutting edge, it wouldn’t take more than a year for Sony to eat their share of the video market on which M43 depends. Having shed the dead weight of 4:3 to reach a plateau of success sometime around 2018/19 the format is perhaps now in its heyday. Enjoy it while you can.