Panasonic Lumix GX8 Review

With the GX8, Panasonic announces a successor to the GX7 that has been further developed in many respects. The GX8 is the new compact top model in the Lumix system camera line-up. It is the first Micro Four Thirds camera ever to use a new image sensor with a resolution of 20 megapixels. With its splash-proof magnesium housing, the GX8 is also more robust than its predecessor. The electronic viewfinder has also been significantly improved.

Short evaluation

Pros

• Pivoting, high-resolution viewfinder as well as rotatable and pivoting touchscreen
• Solid workmanship with splash water protection
• Large scope of equipment including image stabilizer
• Good image quality up to ISO 3,200
• Very fast autofocus

Cons

• No built-in flash
• Viewfinder corners shadow eyeglass wearers
• Menu confusing due to long scroll lists

Not even two years after the ingenious GX7, Panasonic is launching the significantly reworked successor model Lumix DMC-GX8, without betraying the concept. Despite the larger case, however, the built-in flash was omitted. For this purpose, there is a significantly improved flip-up viewfinder, a swivelling and rotating display instead of just a flip-up display, more control elements and splash water protection. Also technically, Panasonic raises the GX8 to the current level with 4K video, improved mechanical image stabilizer, new 20-megapixel sensor, fast DFD autofocus and high continuous shooting speed, as well as silent electronic shutter release.

At the heart of the GX8 is the new 20 megapixel Four Thirds sensor. Despite the higher resolution, the sensor enables high continuous frame rates, covers a wide sensitivity range from ISO 100 to 25,600 and has even been improved in dynamic range. Compared to the predecessor model GX7, the input dynamics are said to have increased by 26 percent. Image processing is provided by a new Venus engine image processor, which is even more powerful with four cores. The mechanical shutter is up to 1/8,000 second fast, the silent electronic shutter even allows 1/16,000 second short shutter speeds.

The Panasonic Lumix DMC-GX8 replaces the GX7 as the compact top model, but the GX7 remains on the market. [Photo: Panasonic]

 

The Panasonic Lumix DMC-GX8 now has a rotating and swivelling touch screen. [Photo: Panasonic]

The viewfinder of the Panasonic Lumix DMC-GX8 can still be swivelled upwards. It now magnifies 0.77x and resolves 2.4 million pixels. [Photo: Panasonic]

With the Panasonic Lumix DMC-GX8 you can record videos in 4K resolution. [Photo: Panasonic]

The front and rear shell of the housing, which has grown considerably compared to the GX7, is made of a magnesium alloy, and the entire camera is protected against dust and splash water. All operating elements are provided with seals, such as the program selector wheel, the underlying exposure correction wheel, the two setting wheels or the new function button on the front of the camera. The GX8 even offers a total of 13 programmable keys. The replaceable lithium-ion battery allows 340 CIPA-standard shots. The rear screen is no longer foldable, but can be rotated and swivelled instead. In addition, the 7.5 centimeter touch screen is a 1.04 million pixel OLED that offers a particularly high contrast of 10,000:1. The viewfinder has also been significantly improved compared to the GX7: It now enlarges 0.77 times according to 35mm, can still be folded up 90 degrees and is better suited for spectacle wearers with the 21 millimetre enlarged exit pupil. An optionally available, larger eyecup also effectively shields scattered light. An OLED with a contrast ratio of 10,000:1 is also used in the viewfinder, resolving 2.36 million pixels in 16:9 format.

Like the GX7, the GX8 has a built-in image stabilizer. For this purpose, the sensor is mounted on movable bearings. Unlike with the GX7, you don’t have to decide which of the two image stabilizers, the one in the lens or the one in the housing, should work. The GX8 can use both image stabilizers at the same time for greater efficiency. While the lens stabilizer works with two axes, compensating angle blur to the left/right and up/down, the sensor stabilizes on four axes. In addition to angular shake, these are also shifts in the four directions. If the GX8 combines the two stabilizers, the angle shake is better compensated by a factor of 3.5 at a focal length of 14 millimeters, and by a factor of 1.5 at a telephoto focal length of 140 millimeters. To use the Dual-IS, however, a firmware update of the lenses is required, the compatibility list can be found on the image below this paragraph. For video recordings, the sensor image stabilizer in the housing is deactivated. The lens stabilizer contributes two axes and an electronic stabilizer compensates for displacements and rotary movements, so that a 5-axis stabilizer is even available here.

Of course, the Lumix GX8 also offers a 4K video function. It works with either 24 or 25 frames per second. In addition to the integrated stereo microphone, there is also a jack connector for an external microphone. In Full HD resolution, the GX8 even achieves smooth 50 frames per second. Panasonic has further improved the 4K photo functions. After all, DIN A4 photos with 300 dpi resolution can be printed without any problems. On the one hand, you can save a 4K photo snapshot from a 4K video. On the other hand, there is also a true 4K continuous-advance function that works at 30 frames per second. The highlight: No matter if you want to record in 4:3, 3:2, 16:9 or 1:1, the 4K resolution is always achieved with a resolution of a little over eight megapixels. The 4K continuous-advance function offers three modes: In normal mode, the shutter release button records 30 frames per second for up to 29 minutes and 59 seconds. The same length restriction also applies to video recordings. In Pre-Burst mode, 30 images are saved before and 30 images after the shutter release. In Start/Stop mode, continuous shooting starts with the shutter release button and ends with the second press.

In addition, Panasonic wants to upgrade the so-called “Post Focus” function with a firmware update at the end of 2015. In 4K mode at 30 frames per second, it is expected to move through a focus area in 50 steps and save the images. Afterwards, you can save a photo with the focus at a selected position at any time. Light field photography offers a similar function, but with a lower resolution.

Autofocus is provided by Panasonic’s DFD technology. From two differently focused, blurred photos, the GX8 can predict the focus distance as with a phase autofocus and only needs the contrast autofocus for fine adjustment. This means that the GX8 is in focus in just 0.07 seconds and is therefore twice as fast as its predecessor, the GX7. Thanks to lowlight AF, the GX8 even focuses at -4 EV ambient light, such as moonlight. It can also focus on stars in the sky. Otherwise the autofocus works with up to 49 measuring fields and detects not only faces but also eyes. In addition, the focus can be changed to a field of selectable size or even to a tiny pinpoint AF for focusing even smaller subject details. The focus point can be placed with fingertips using the touch screen. Manual focusing is supported by the focus magnifier and focus peaking. In full resolution of 20 megapixels, the GX8 shoots eight continuous frames per second, with AF tracking it’s still six frames per second. The GX8 can now also predict motif movements in order to keep objects in focus even better.

The Panasonic Lumix DMC-GX8 is the first Micro Four Thirds camera to use a new 20 megapixel image sensor. [Photo: Panasonic]

The case of the Panasonic Lumix GX8 is bigger than the case of the GX7, but offers a splash water protection. [Photo: Panasonic]

The Panasonic Lumix DMC-GX8 uses fast hybrid contrast autofocus with DFD technology. At up to six continuous shots per second, it can adjust the focus. [Photo: Panasonic]

The Panasonic Lumix DMC-GX8 communicates with other devices via built-in WLAN. Thanks to NFC or optional QR code, the connection is set up in a flash without entering a password. The GX8 can then send images to smartphones, tablets, televisions or printers. The corresponding app for Android and iOS even allows remote control of the camera with live image transmission. But the Lumix can also be remote controlled from a computer thanks to USB tethering. As a new accessory, Panasonic also wants to offer a USB remote control with which the GX8 can be remote controlled. The remote control should allow you to set various parameters for taking pictures. But a classic cable remote release can also be plugged into the Lumix.

Ergonomics and workmanship

Those who know the predecessor model GX7 will immediately notice that the successor model Lumix DMC-GX8 is one size bigger. The GX8 is compact, but no longer really small. But Panasonic has found a good compromise between size, robustness, weight and ergonomics. With its splash-proof metal housing, the GX8 makes an absolutely high-quality, stable impression. Large applications of grained rubber, which however should be a bit more handy, give the GX8 a noble appearance. The handle is large enough to give good grip without being as huge as a DSLR. Of course, the handle does not fill the whole hand, even the little finger only barely finds a hold on the handle. The shutter release is well reachable on top, but should have some more crisp pressure points. It is surrounded by one of the two rotary knobs, which can be used to set various parameters such as aperture, exposure time, white balance or ISO sensitivity. As with Olympus, a button in the middle of the thumbwheel switches between two different assignments.

 

The Panasonic Lumix DMC-GX8 has a robust metal housing, numerous seals protect against the penetration of splash water and dust.

The exposure correction, however, has its own rotary wheel below the program selector. Here it is also quite safe from accidental operation. By the way, the built-in flash had to give way to this “turret”, and Panasonic does not even supply a small clip-on flash with the camera, which costs just under 1,200 euros. Not only the three program memory locations, which can be called up directly with the program selector wheel, but also no less than 13 function keys, some of which can be found as virtual touch keys on the screen, provide the necessary adaptation to the respective photographer. But even the normal buttons allow access to numerous recording settings including a rotary selector for the focus mode on the back of the camera.

The housing of the GX8 is protected against splash water and dust. However, Panasonic does not have too many protected lenses in its portfolio. It gets a little better when you add the Olympus lenses. The flap on the underside of the handle seals by means of a circumferential rubber seal. The lithium-ion battery with a capacity of over 340 shots and the SD memory card can be stored here. Due to the 4K video function with 100 Mbps data rate, an SDHC or SDXC memory card that complies with the UHS-I standard U3 and therefore has a guaranteed minimum write speed of 30 MByte per second is recommended. A memory card of this type is also recommended for continuous shooting. However, the faster UHS II standard is not supported by the GX8. By the way, the tripod thread is located in the optical axis and is also reasonably far away from the battery and memory card compartment.

The three interfaces of the GX8 are located on the left side of the case. They are protected by a rubber cap which is secured to the housing. She’s a little fiddly and tight. In addition to the micro HDMI connection, these include a combined USB AV socket and a 2.5 mm jack connection, which can either accommodate a cable remote trigger or an external stereo microphone. So for many microphones you will need an adapter. The glossy metal bayonet ring is surrounded by a wider ring that forms part of the metal housing and optically enlarges the outer diameter of the bayonet. But if you use slim lenses, as we did in the test with the 14-42mm, the lens looks a bit chic on the camera. The GX8 is designed for larger calibers like the 12-35mm 2.8, which is also available as a set with the camera. In contrast to the 14-42mm, this lens is then protected against dust and splash water.

A unique feature – in the truest sense of the word – is the electronic viewfinder that can be folded upwards by 90 degrees. This makes the Lumix GX8 one of the very few cameras with a built-in angle finder. Thanks to the eye sensor, the 2.36 million pixel OLED activates itself. The magnification factor of the viewfinder corresponds to 0.77x on a 35mm DSLR – in other words, the viewfinder is really big! You get the impression you’re looking at a screen. The viewfinder also flickers much less than many other OLED viewfinders. It works practically instantaneously and thanks to 60 frames per second refresh rate also jerk-free. Only spectacle wearers have a problem: The corners of the large viewfinder shadow with glasses because the exit pupil is slightly too small. After all, the Panasonic offers a wide range of diopter correction from -4 to +3 dpt.

Thanks to the pan and tilt mechanism, the screen can be folded upside down against the camera. The back is also provided with a grained rubber appliqué, so that the screen, which is folded up in a protected way, looks extremely noble. The screen itself measures 7.5 centimetres diagonally and has a resolution of one million pixels in keeping with its status. It is also an OLED, which makes the screen absolutely stable in viewing angle. Thanks to touch capability, the camera can also be operated via the screen – even if only to set the focus point, which also works excellently when viewed through the viewfinder. The Live-View offers useful insertions like different grid patterns, a 3D spirit level and a live histogram – no matter if you look through the viewfinder or on the monitor.

The built-in flash of the Panasonic Lumix DMC-GX8 has been replaced by a rotating wheel turret. At the bottom, the exposure-compensation dial and then the program dial. [Photo: Panasonic]

The Panasonic Lumix DMC-GX8’s 7.5cm rear touchscreen swivels sideways and rotates up, down and forward.

Some settings that, depending on the key assignment, cannot be reached via the direct selection key, for example the image resolution or the file format, can be quickly reached via the Quick menu. The main menu of the GX8 allows even more profound settings of the camera functions, including key assignment. The menu is divided into several sections, which in turn are filled with up to nine pages of menu lists. There is a different way to get a clear overview, and so some menu entries have to be searched for with difficulty. The menu can also be completely operated via touchscreen.

Equipment

Thanks to the program selector wheel, the Lumix GX8 can be easily adjusted for fast photography in iA mode, but also allows individual semi-automatic or manual adjustment thanks to creative programs. In iA mode, the GX8 automatically selects the appropriate scene mode based on the subject and adjusts, for example, ISO sensitivity, exposure time and image stabilizer based on subject and photographer movements. For manually selectable motif programs, however, there was no more room on the program selector. After all, the panorama mode and the creative filters, of which the GX8 has a large selection to offer, have made it onto the dial.

In addition to an extensive exposure bracketing function with three images and 1/3 EV levels of exposure distance up to seven images with up to one EV exposure distance, the Panasonic also offers an HDR function. This takes three images with up to +/- three EV exposure distances, aligns them automatically when this option is activated and combines them to a successful HDR image. The GX8 doesn’t overdo it with the tone mapping, so that quite natural-looking photos are created, which, however, do show the HDR effect. The GX8 can also handle multiple exposures, time-lapse shots and their automatic combination into a stop motion animation.

The continuous shooting mode reaches a respectable eight frames per second and with the JPEG format there seems to be no limit at all, so quickly the photos are saved away. In raw format, the buffer is full a bit faster. With a little trick, however, the speed of the series can be increased even further: if you switch to the silent, electronic shutter, more than twelve series shots per second are achieved. After a good 90 shots in JPEG and about 30 shots in Raw, the GX8 is finished in a continuous run of three or 1.5 series shots per second. It goes without saying that despite the fast autofocus of 0.06 to 0.1 seconds, this is no longer tracked. In addition, there are problems with the rolling shutter effect with fast movements or swivels. When autofocus tracking is activated, the continuous shooting speed drops to six frames per second with mechanical shutter and ten frames per second with electronic shutter. As a nice side effect, the Live View also remains active, so that you don’t only always get the last shot of the series displayed, which is especially helpful for draggers, because the scene mode with Live View doesn’t run out of the image section so easily unintentionally.

Even faster continuous shooting pictures including live view and autofocus tracking are available in 4K continuous shooting mode, which works at 30 frames per second. However, this only captures about 8.3 megapixels from the center of the sensor. Thus, one loses the angle of view but gains tele on the other side (factor 1.55). Very practical is the possibility to set the aspect ratio to 1:1, 4:3, 3:2 or 16:9 without losing resolution. Different modes allow a continuous shooting as long as the shutter release button is held down or the first press starts the series and the second press stops it. In the third mode, continuous pictures are taken before and after the shutter release button is pressed, so that the correct moment can still be captured even if the shutter release button is pressed too late. 30 pictures are taken before the shutter is released, one at the time of release and 29 afterwards, i.e. a total of two seconds and 60 pictures respectively. However, the continuous-advance images are always video recordings, and the appropriate individual images can be extracted in the playback function.

The silver bayonet ring of the Panasonic Lumix DMC-GX8 is surrounded by a wide black ring. This makes small lenses on the GX8 look chunky, but it fits well with voluminous lenses.

The metal tripod thread on the Panasonic Lumix DMC-GX8 is located in the optical axis. The distance to the battery and memory card compartment is also sufficient.

The 4K continuous mode is also used with the new post-focus function: the fast autofocus moves through up to 49 focus positions during a series. Later in the playback, the focus can be set in the image and the single photo can be extracted from the video with a fingertip. The focus magnifier and focus peaking are also available. A very clever function if some resolution is omitted.

Regarding Focus: The GX8 works with DFD technology. Two images with different focus positions are compared and the correct focus point is predicted based on these and the lens characteristics. The normal contrast autofocus is only used for fine adjustment. Focusing is thus significantly faster than with pure contrast autofocus. Within only 0.06 to 0.1 seconds, the Lumix GX8 focuses, but there is also a shutter release delay of 0.06 to 0.07 seconds, which occurs independently of the focusing. This is “only” on DSLR level, while the autofocus works faster by classes.

Even in low ambient light, the autofocus is not beaten, it still works at up to -4 EV and can, for example, focus on stars in the night sky. If you want to focus manually, the focus magnifier, which automatically activates when the focus ring is pressed, and focus peaking help. It highlights sharp contrasting edges in color so that the focus plane can be seen better. Peaking also works in combination with the focus magnifier. The latter in turn can be adjusted in the magnification factor and section. But also the autofocus allows far-reaching settings from multi-field to a movable field up to a tiny focus field, which a bee can focus on a flower exactly and can even track and hold in focus by means of tracking function.

The video function of the GX8 also works in 4K resolution, but with the European model only with 24 or 25 frames per second. As with the 4K photo function, the image detail is strongly cropped. If you switch down to full HD resolution, the whole sensor surface is used and there is only the loss of the image angle due to the 16:9 aspect ratio on the 4:3 image sensor. In addition, very fluid 50 frames per second are possible in Full HD. Instead of MP4 with up to 100 Mbit/s, you can also record in AVCHD format with up to 28 Mbps (maximum Full HD resolution). The audio level is controllable and can be transmitted to the video recording either via the integrated or an external microphone. Also various manual settings up to exposure time, aperture and ISO sensitivity as well as a Zebra function are available.

Since the GX8 doesn’t have an integrated flash and no attachable flash is included, you have to buy a large system flash that fits on the flash shoe. This then allows various functions and flash modes, flash exposure correction, etc.. The shortest flash sync time with mechanical shutter is 1/250 second. Unfortunately it is not possible to flash with an electronic shutter, here the rolling shutter would cause strange effects.

In Playback mode, you can edit photos in JPEG and Raw as well as videos, while the editing functions for photos are much more luxurious, even including effect filters. Thanks to its built-in WLAN module including NFC, the GX8 allows photos to be sent wirelessly to mobile devices or via DLNA, for example to televisions for further viewing. With the help of the appropriate app, the GX8 can also be triggered remotely while the live image appears on the smartphone screen. Like the GX8, Panasonic’s App offers a rich bouquet of features and settings so the App goes far beyond a simple remote trigger. However, the GX8 can also be operated classically by cable remote release.

The 14-42mm lens makes it easy to see that the Panasonic Lumix DMC-GX8 is no longer a small camera.

The battery and memory card of the Panasonic Lumix DMC-GX8 are removed from the common compartment on the underside of the camera. Here, too, a seal protects against the penetration of splash water.

Picture quality

The Panasonic Lumix DMC-GX8 is the first Micro-Four-Thirds camera to be equipped with a new 20 megapixel sensor, up to now 16 megapixels were the limit. Despite the increased resolution, Panasonic promises low noise and a high dynamic range.

In fact, the Lumix DMC-GX8 with the 14-42 mm II used in the test achieves a resolution about 15 percent higher than the Lumix DMC-G70 also tested this year with the 14-42 mm II, which only resolves 16 megapixels. So you can say that the 20-megapixel sensor actually makes a higher resolution usable than the 16-megapixel sensor; even with the simple set lens. On the GX8, the 14-42 II achieves a maximum resolution of nearly 51 line pairs per millimeter (lp/mm) in the center of the image, measured at 50 percent edge contrast (MTF50). However, this high resolution is only achieved in the wide angle and only in the center of the image. In the range from F3.5 to F8, the resolution is close to 50 lp/mm and thus at a high level. Even with F11 a high resolution of over 40 lp/mm is achieved. When dimming down further, the diffraction then strikes mercilessly. At the edge of the picture, however, it looks significantly worse. Here, the resolution is a good 30 percent lower at a maximum of 35 lp/mm. At medium focal length, a slightly lower resolution of maximum 48 lp/mm is achieved in the center. When stopped down on F8, the edge of the image gives 38 lp/mm, while in the center it is 46 lp/mm. In the longest focal length position, the resolution decreases further, but the center and edge of the image are no longer so far apart and maintain a fairly constant distance from each other. The maximum here is 41 lp/mm in the center and 36 lp/mm at the edge of the image with an aperture of F8.

By the way, the chromatic aberrations of the lens are low, even at the maximum they hardly reach more than one pixel width. The distortion also remains at a low level with a maximum of 0.5 percent tonne or cushion shape, depending on the focal length. Here the JPEG image processing clearly has its fingers in the pie. Even the edge darkening remains small. All in all, the 14-42mm II delivers good results on the GX8 and is quite suitable as an entry-level lens. The fact that not even fixed focal lengths have to be able to tear it out is shown by the tests of the 25 mm 1.7 and the 42.5 mm 1.7, both of which do not reach the resolution of the 14-42 mm II, but are better at the edge of the picture to some extent. Only the 30 mm 2.8 macro can reach the 50 lp/mm mark. However, all three fixed focal lengths are quite inexpensive models. With the expensive 42.5 mm 1.2 Leica, for example, there would certainly be a higher resolution in it, as it already reaches almost 50 lp/mm on the GH4, although it only offers 16 instead of 20 megapixel sensor resolution.

But the new 20-megapixel sensor is not only impressive in terms of resolution. The GX8 offers an acceptable signal-to-noise ratio of 35 to 40 dB in the ISO 100 to 6,400 range, making it slightly better than the Lumix G70 at high ISO sensitivities. Luminance and colour noise remain at a low level. However, the noise reduction up to ISO 1.600 lets through a lot of details, there is practically no loss of fine textures. Only above ISO 3.200 does the noise suppression result in a significant loss of detail, the images appear softly washed.

The dynamic range is astonishingly high with up to twelve f-stops at ISO 200. Interestingly enough, the dynamic range up to ISO 1,600 drops to a still good 10.5 f-stops and then rises again. Obviously Panasonic activates an additional noise suppression, which provides a deeper black that is not “brightened up” by noise pixels. The tonal value curve runs as usual divided for crisp contrasts with medium brightness. The output tone range moves up to ISO 6,400 at a high level of 160 and more of 256 maximum possible levels. Here, too, an increase from ISO 1,600 to ISO 3,200 can be observed.

The Panasonic Lumix DMC-GX8 has a handgrip that is small but still has a good grip.

The electronic viewfinder of the Panasonic Lumix DMC-GX8 can be folded up 90 degrees. The interfaces are all hidden on the left side of the camera.

The color deviation of the GX8 is on average small, although some colors show slightly stronger deviations. These are mainly caused by a stronger saturation of individual colour tones, for example in the blue and magenta areas, and less by a colour shift. The color depth is also very good with at least four million displayable colors up to ISO 6,400 and moves on a higher level than with some other cameras. All in all, the 20-megapixel sensor not only provides the expected increase in resolution, but the sensor can also convince in other disciplines together with Panasonic image processing and one can be curious to see when the next cameras with this advanced sensor will appear.

Bottom line

The Panasonic Lumix DMC-GX8 is a very well crafted and robust mirrorless system camera with a top equipment that is partly unrivalled. Only the folding viewfinder or the 4K series picture functions are second to none. But Panasonic has also succeeded in improving the ergonomics of the camera, as long as the camera can be made to measure thanks to its strong customizability. However, the menus suffer a little from a lack of clarity due to the wide range of functions. A problem that other camera manufacturers also have. The modern cameras are packed with many functions, of which you normally only need a fraction. However, every photographer needs different functions depending on the subject, so that the GX8 is a true all-rounder, which also convinces with the image quality. The GX8 is certainly currently the Panasonic with the best image quality, it offers with its new 20 megapixel sensor visible advantages over the previous 16 megapixel models, and not only in resolution. Only the price of the GX8 is already quite high at around 1,200 Euros, even if it is more than adequate in terms of performance.

Panasonic Lumix DMC-GX8 Datasheet