(Pocket-lint) - We've often thought of the Panasonic GH series as the best consumer interchangeable lens system for video capture on the market. It's not hard to see why: the Panasonic Lumix GH4 offers 4K video capture at usable frame rates. On paper that's untouchable at this level.
But when Panasonic first introduced the GH4 to us the company was adamant that it is a stills camera first and foremost. In the back of our minds we disagreed. So what did we do? Loaded up the GH4 on a trip to the States and have been using it non-stop in varied real-world situations to test its mettle.
We've obviously been delving into video capture too, but throughout testing this camera the one question that's been circulating in our minds is this: can a £1299 compact system camera match up to or, indeed, better a mid-level DSLR such as the Canon EOS 70D?
A different beast
Only three paragraphs in and we've already indulged in the "compact system vs DSLR" conundrum. Sorry about that. But really the GH4 feels like a different kind of beast.
Over the course of our week of testing the one thing we've really noticed is how much we utilised the GH4's vari-angle LCD screen. Because this is a mirrorless system its live preview is super quick. Waist-level shots, overhead work and so forth have been commonplace. The Canon 70D also has a vari-angle screen and very good live view operation, but the GH4 is just better in this department.
READ: Canon EOS 70D review
The other standout feature is an electronic shutter. There's a mechanical one too, but the electronic one is silent and this is great for candid shooting. No machine-gun-like clatter when whirling through the 12fps max burst mode, for example, has been a refreshing way to shoot.
All this comes wrapped up in a sturdy, weather-sealed body that feels like a genuinely well built piece of kit. It's heavy but not to excess, while the Micro Four Thirds lens mount means access to stacks of lenses. The 14-140mm f/3.5-5.6 lens (24-280mm in equivalent terms) we've been using is small but provides a considerable zoom range given its size.
Customisable to the max
In terms of design we're also very taken by how accessible everything is. There are bundles of controls on the GH4's body, from the more standard mode dial - which comes complete with a cool click-to-lock button - alongside dual thumbwheels, a rotational rear d-pad and dedicated drive mode dial.
But there's much more. An autofocus type switch selector to the rear surrounds the AF/AE lock button, while five physical function buttons are arranged around the body: one on top, three to the left side of the d-pad to the rear, and the final one to the left side of the viewfinder. Each of these can be customised to suit your use, although with a further three buttons for white balance, ISO and exposure compensation control positioned on top we doubt you'll necessarily need to adjust the default settings for each.
Such a layout speeds things up considerably in use. Few other compact system cameras make switching from single to continuous autofocus as simple as flicking a switch, for example, which we've come to find useful when flitting from shooting the Washington Monument to nabbing a shot of a squirrel skipping through the grass.
Our only real complaint about the layout is that things are a little cramped in some areas. With the screen in its "normal" position we've found hitting the Fn2, Fn3 and Fn4 keys an occasional nuisance because the screen protrudes from the body more than each of them. Trim a few millimetres from the edge of the screen - there's bezel to this outer edge too, not actual display - and it would make all the difference.
The switch around the autofocus selector also ought to be more considerable we think; it's a fairly pokey little thing that a thumb can slide over sometimes. Next to this there's the one-touch movie button which rests close to where your thumb naturally sits when gripping the camera. We never accidentally actioned the button, but could see how this might be possible; simultaneously it's well placed to give it a press from a firm hold without there being an initial "judder" in video capture.
Another clear positive about the GH4 is its autofocus system. There's some brand new tech at work here, known as DFD - depth from defocus - for optimum performance with Micro Four Thirds lenses. Each lens's minimum and maximum defocus points are known, and such data can be extracted via the electronic coupling between lens and body to deliver a defined range to minimise unnecessary focus hunting. It makes for really, really fast focus. A half press of the shutter seems to instantly obtain focus with a gratifying "beep" and green focus area on screen. Or if, like us, silence is important the beep can be deactivated.
But it's not speed that's the only important factor. Accuracy is key too and, from looking back through our pictures, that seems to be spot on - there's no compromise for the sake of making focus that bit faster. And when using a camera knowing that it'll just do what you want, how you want, it means more confident use.
Low-light fares very well too. Not surprising given that the GH4's autofocus system is rated to operate right down to -4EV. There's nothing else on the market we can think of that offers such sensitivity, not even at the top-end of the market. Whether it makes a huge difference in practice, we can't specifically tell. All we know is that neon signs, and subjects in the dark of night were all easy pickings. On some occasions the specific focus area wouldn't be able to focus, instead presenting a much larger average focus area around the majority of the scene. Sony has a similar action that occurs in dim conditions, which we find limits the pinpoint accuracy, but still gets the shot.
Autofocus comes in many flavours: face/eye detection; tracking; 49-area auto; custom multi which offers multiple user-selected points to be activated; 1-area; and pinpoint make up the six available settings. You probably won't opt to use them all in real life, but even staunch "single point" shooters like us found a lot of relevance in the custom and pinpoint modes. Coupled with the LCD's touchscreen control there's scope to tap a subject on screen to focus and even to automatically fire the shutter should you wish.
Pinpoint is our favourite of the bunch, a mode we've long been championing and one that only Panasonic offers at present. A cross-hair focus area can be placed by tapping onto the screen and when focusing the surrounding area zooms in to 100 per cent scale to confirm accurate focus has been acquired. This has changed slightly as the earlier generation would use the full screen to magnify. It's a small but sensible change in the GH4 as the remaining composition can be previewed for better framing.
The 1-area mode is as it sounds: plonk a single area on the screen and that's your focus point. Using the rear dial it can be enlarged from its smallest offering through a further seven size increments. If using it large it's a bit like selecting a group of focus points on a DSLR.
Custom multi is somewhat more interesting as it's designed for specific shooting scenarios, such as panning while shooting a moving subject. A horizontal line of focus points is one option, for example, which will avoid the camera so much as thinking about what's going on in other areas. But as it's customisable it needn't be entirely rigid: press the screen to present the 49-area grid and click to highlight the focus areas you wish to activate; they'll fill in an orange colour to confirm and the last point selected will act as the "lead". Then save your selection in one of three custom slots. Easy.
Fast, accurate, detailed: there's not a compact system camera more varied or capable than the GH4 when it comes to autofocus ability. Other companies might argue they have the fastest offering when paired with a specific lens, but it's in such fractions of a second that the difference is becoming increasingly negligible. It's all good.
There's often a lingering question about Micro Four Thirds image quality: is it good enough? The sensor size isn't as large as DSLR equivalents, but we've already seen how far the format can go. Just take a look at the Olympus E-M1.
READ: Olympus OM-D E-M1 review
So there really needn't be the question. In the same way that the Olympus impressed us, the brand new CMOS chip in the Panasonic GH4 does a grand job at rendering good-looking images. There's not a huge gap between one generation and another these days, and the divide between the DSLR world and the compact system camera has closed enough to not really worry about it.
There are some caveats, though. We're fonder of the sharpness achieved by the lowpass-filter-free Fujifilm X-T1. And as full-frame DSLR users we prefer the shallower depth of field available to us at equivalent apertures too. Which lens you choose will make a difference too, obviously, as we found some purple flare from the 14-140mm could be a pain in sunlight - our fault for leaving the lens hood behind really.
READ: Fujifilm X-T1 review
In terms of sensitivity, ISO 200 is the GH4's starting point. We always want ISO 100 to be available, but here it's only an "extended" option, which is fairly typical of Micro Four Thirds sensors. We've taken plenty of shots at this lowest standard sensitivity and results are pleasing, but as it's our job to scrutinise - and we've been taking a very close look - we have spotted some image noise in mid-grey areas. Not enough to be a bother us really, but after shooting lots of stone statues it is certainly possible to pick out some colour noise in the darker areas.
The level of visible noise in JPEG shots doesn't drastically increase as the sensitivity rises, which is a positive. This is one of the GH4's clear strengths: its ability to maintain detail. A shot of the President Lincoln statue at the Lincoln Memorial taken at ISO 1600 shows more noise than a busier, more colourful shot would. There's a bit more grain but rather than go over the top with harsh image processing we like how the GH4 seems strikes a fair balance.
Sometimes the GH4's images lack smooth gradations though, with pixellated patches of colour visible when viewing at 100 per cent scale. The JPEG files all seem to be "boosted" in terms of exposure compared to their raw counterparts too, which further highlights the visibility of these clusters. Like we say, this is Panasonic looking to maintain detail rather than process the life and sharpness out of an image. It does sometimes limit how much post-production work you'll be willing to do on a shot though, as this ISO 200 shot of the Capitol building begins to show patches in the sky.
Panasonic Lumix GH4 review - sample image at ISO 200 (distortion, contrast and curves adjustments made)
As we've come to appreciate throughout this week shooting using a sensor of this size also has its benefits. Although the GH4 isn't a small camera in this overall category, it's much lighter than what we would usually carry around and the equivalent focal length means small lenses have a lot more reach.
Shooting birds taking a bath outside the White House showed just how close-up we could make a subject in the frame using the 14-140mm lens at its maximum extension. A bit of cropping later, burst mode in full swing, electronic shutter selected, and we've got some spectacular shots.
Panasonic Lumix GH4 review - sample image at ISO 200 (cropped and rotated), 1/400th sec
In short, we've been able to use the full standard ISO range without flinching. Resulting quality has always been decent, roughly on par with the Olympus E-M1. That speaks volumes in itself.
Where the GH4 makes massive leaps and bounds ahead of the competition and, indeed, its GH3 predecessor is with its 4K movie mode. And we don't mean a half-baked version - it can shoot 4K (3840 x 2160) at 100Mbps using ALL-Intra compression at 30/25/24fps. Access to these frame rates is defined by the frequency settings: NTSC, PAL and "Cinema" are available, the last option opens up a 4096 x 2160 24p aspect ratio too.
To use 4K capture you will need to be in the dedicated movie mode on the main mode dial, otherwise things are restricted to 1080p maximum. Not exactly a bother, but something of note. Part of the reason is because a significant portion of the camera's sensor is used to capture 4K (around half of it, at 8.3-megapixels), so Panasonic has also opted for a straight "pixel for pixel" capture system. The top and bottom sections of the sensor aren't needed for capture and so are binned which means a true representation - no pixel mapping, binning or zooming required to obtain the final output. The different crop means a 17 per cent addition to equivalent focal length, so if you're using a 50mm Micro Four Thirds lens (100mm equivalent for stills) then you'll achieve a 117mm equivalent for 4K capture. Something to keep in mind, but a benefit as the central portion of a lens' imaging circle will be sharper than the outermost edges, which is exactly where the frame falls.
The one thing that perplexes us the most about the GH4's movie prowess is nothing to do with the actual modes on offer, but the presence of just one SD card slot. We're surprised the designers didn't opt for dual slots. When writing to the SD card the camera captures 4K video with 8-bit colour and the data rate is limited to 100Mbps in either MP4 (LPCM) and MOV formats. Outside of Cinema mode there are AVCHD and MP4 options with lower compression rates available.
Use the optional pro-spec DMW-YAGH accessory - which is about as big as the GH4 body - and its four SDI ports can be used in tandem to extract uncompressed 4K at 10-bit colour. Power input, independent volume adjustment and twin XLR sockets ensure everything a broadcast pro could want is here. But only if you're running a rig with the YAGH - and most consumers won't ever need that.
If you're tempted by the prospect of "normal" 4K without the added accessory bulk then you're going to need powerful hardware to edit, a large SD card to hold that footage, and a greater-than-1080p device to enjoy the playback. And enjoy you will: the footage looks glorious and is packed with detail.
If 4K is a bit too far ahead of your desires then the current 1080p standard is very well catered for by the GH4 too. It can capture content direct to SD card at 200Mbps, which is far beyond broadcast standard.
Quality of capture is great, but so is control. Touch the screen to shift the focus point during capture, there are full manual controls if you want them (P, A, S, M), a 3.5mm mic jack for audio capture, and continuous autofocus that's as good as it gets in this format. Pro stuff such as zebra pattern, time code, sound levels and levels adjustment also feature should you happen to want them.
There's so much detail in the GH4's movie capture options, but it needn't be baffling. Point and shoot, or dig deep thanks to manual controls - it's all available here. Nothing else on the market can compete with it at this level and price point. It's top quality and will be a considerable reason that many will look to buy this camera.
With so much tech eating away at battery life, we found this to be among the GH4's weakest areas. It's not bad, but with around 500 shots per charge it's less than a similar priced DSLR. If you're shooting lots of video then the battery will seem to deplete quickly, in which case we would recommend buying the battery grip accessory to double up on battery life. Two batteries are better than one after fall.
One thing that frustrates us - and this is a general camera criticism, not just a GH4 thing - is the way battery life is displayed. The remaining power is shown on the GH4's screen as a battery icon divided into thirds, which lacks the accuracy of a percentage display. There's no accurate way to judge when you'll drop from two thirds to one third, for example.
On board Wi-Fi further eats away at battery life, but it's there if you need it to share images when pairing with a smart device such as your smartphone. We find the Panasonic app is functional but it lacks some of the third party compatibility of its competitors.
Throughout our week of using the GH4 we've been very impressed with what it can do. We've found using the vari-angle LCD screen great to shoot over the heads of tourist crowds in sunny Washington, have seen New York non-stop downpours soak the camera and cause no problems (our socks, meanwhile, were squelching with each step), while the resounding speed of operation is truly standout. The new details in the autofocus modes and the way it deftly cuts through raw and JPEG files at 12fps is accomplished.
We've used the camera somewhat differently to a DSLR, but haven't found it to limit our abilities at any turn. The sensor size has meant an easy-to-carry device with sufficient zoom from the 16-140mm lens, and the 2,360k-dot OLED electronic viewfinder does a decent job too, even if it's not as impressive as the Fujifilm X-T1 in this regard.
Image quality is roughly on par with its nearest competitors, although processing has been balanced towards sharpness which can sometimes reveal a lack of smooth gradation, with clusters of pixellated colours showing up in areas. That might have cost the GH4 its perfect score, but it's the 4K movie mode that sees the GH4 land in a special place. It's so far ahead of the competition in this regard that it's currently untouchable. We're sure plenty will all but ignore the stills shooting ability and buy a GH4 for its 4K capture capabilities.
The GH4 sees the GH series finally land with a bang. It's not a budget device, but there are points of brilliance throughout all its important areas. It's really the best-in-class video mode that makes the GH4 one serious camera to be reckoned with. It's no longer so much "compact system vs DSLR", it's about which camera is best, and the GH4 ticks so many boxes it'll be known as one of the best cameras to arrive in 2014.