Panasonic GX7: Numerous technical highlights combined in a compact housing

With the new Lumix DMC-GX7, Panasonic is setting standards in the DSLM sector (mirrorless system cameras) with numerous technical highlights and virtually full equipment. The Japanese manufacturer combines technologies in a compact housing that cannot be found anywhere else in this combination: a sensor shift image stabilizer, which can be found for the first time at Panasonic, a compact “briquette” magnesium housing, a high-triggering, foldable electronic viewfinder, a folding touchscreen, WiFi, NFC, a short exposure time of 1/8,000 second and a 16 megapixel resolution sensor with a maximum light sensitivity of ISO 25,600.

Short evaluation

Pros

• Very large scope of equipment
• Extremely fast autofocus
• Foldable EVF with excellent viewfinder image
• Good image quality up to ISO 3,200 with very high input dynamics

Cons

• Weak resolution performance of the set lens
• Flash exposure correction can only be reached via the main menu in an awkward way
• EVF with glasses hardly usable
• Some powerful noise suppression leads to loss of detail

 

The Panasonic Lumix DMC-GX7 has an electronic viewfinder with a resolution of 2.76 million pixels that can be tilted up 90 degrees – the current record! [Photo: Panasonic]

Light, compact and yet an equipment list that meets all requirements: With the Lumix, Panasonic wants to secure its place on the Olympus list of handy, mirrorless system cameras. In addition, the GX7 has a few helpful features in the luggage: An electronic viewfinder for example, which can be swivelled vertically upwards. Or a WiFi connection for wireless image transmission and remote control of the camera. Panasonic has also over-processed the image sensor so that it makes even less noise.

The Panasonic Lumix DMC-GX7 has an extremely compact housing of 123 x 71 x 43 millimetres. It consists of a magnesium alloy and is characterized by a high robustness. Also the full weight of about 400 grams including battery but without lens should underline the robust impression. Despite its compact dimensions, Panasonic was able to integrate a flash shoe, a pop-up flash with a guide number of 5 and an electronic viewfinder. The curved handle covered with a grained rubber is intended to improve the handling of the briquette-shaped camera. The electronic viewfinder sets new standards with its resolution of 1,280 x 720 pixels (2.76 million pixels). It covers almost the entire Adobe RGB color space and shows 100 percent of the subject. The 0.7-fold magnification (compared to 35mm) and the eye distance of 17.5 millimeters are also impressive. In addition, the viewfinder can be folded up by 90 degrees, so you have an integrated angle finder for comfortable shooting at chest or floor level. The integrated eye sensor not only automatically activates the viewfinder, but also the autofocus so that the camera is ready for use even faster.

The Lumix DMC-GX7 is the first Panasonic to be equipped with a sensor shift image stabilizer. However, the optical image stabilizer of an attached lens is automatically preferred. [Photo: Panasonic]

The rear screen can also be seen with its 1.04 million pixels in 3:2 format at a diagonal measuring 7.5 centimeters. Here, too, the Japanese manufacturer was able to improve the display quality and at the same time save energy through more effective backlighting. The lithium-ion battery of the GX7 should be sufficient for 350 shots according to CIPA standard measurement procedures. The screen not only folds 80 degrees upwards, but also 45 degrees downwards, making it easier to take pictures above your head or near the ground. The screen is touch-sensitive, so that the camera can also be operated directly via the display. In addition, there is the (switchable) option of triggering the camera via the screen, and focusing with a fingertip is also possible. In video mode, you can even use this function to shift the focus from one point to another.

The Panasonic Lumix DMC-GX7 is a mirrorless system camera, Panasonic likes this DSLM (Digital Single Lens Mirrorless). The GX7 belongs to the Micro-Four-Thirds-System. [Photo: Panasonic]

Panasonic has completely redeveloped the live MOS image sensor, with the Japanese manufacturer sticking to a resolution of 16 megapixels. Thanks to the latest technologies in semiconductor manufacturing and enlarged photodiodes, both the sensitivity and the colour saturation could be increased by 10 percent each, an improved reading of the image signal even increases the signal-to-noise ratio by 25 percent. In addition, there are new noise reduction technologies from the Venus Engine image processor, which, for example, are designed to reproduce human skin even more naturally, even at high ISO values. The maximum sensitivity is now ISO 25.600. The new “Intelligent D-Range Control” is also intended to provide a wider dynamic range with even gradation and finely defined highlights and shadows. For the first time in a Panasonic a sensor shift image stabilizer is used, so that all Micro-Four-Thirds lenses as well as adapted ones are stabilized by the camera. For lenses with optical image stabilizer, this is automatically preferred.

The Panasonic Lumix DMC-GX7 can be operated not only via the touchscreen, but also via buttons and two control wheels. [Photo: Panasonic]

The GX7’s contrast autofocus operates at a frequency of 240 frames per second, making it particularly responsive. The Lumix achieves a maximum continuous shooting rate of five frames per second, with autofocus tracking it should still be 4.3 frames per second. Panasonic emphasizes not only the high accuracy of the autofocus, which is supposed to be given even with fast lenses with open aperture, but also the low-light capability. The contrast autofocus can still focus down to -4 EV, which, according to Panasonic, corresponds to the illumination under a clear starry sky without further light sources. Of course, the GX7 can also be focused manually, for which not only a magnifying glass with fine magnification steps is available, but now also a peaking function that highlights edges with high contrast (synonymous with high sharpness) in color. The user can choose between blue or orange highlighting. The Peaking function can also be used when combining autofocus with manual fine-tuning. When focusing manually, autofocus can be activated at any time by pressing the AF button.

On the back, the Panasonic Lumix DMC-GX7 has a 7.5 centimeter touchscreen with over a million pixels of resolution, which can be folded 80 degrees up and 45 degrees down. [Photo: Panasonic]

Speaking of operation, the GX7 has a mode dial and two control wheels for convenient setting of two parameters, such as aperture and exposure time in manual mode. Panasonic has also improved the intelligent automatic system, and the scoreboard recognition system now also automatically recognises the “Food” program. Panasonic has extended its digital filter effects to 22, all of which can be parameterized and almost all of which can also be used for video recording. Also on board is a panorama function for vertical or horizontal panoramas with up to 360 degrees. In addition, the GX7 has the shortest exposure time of 1/8,000 second, which means even more flexibility when using fast lenses in bright environments. Alternatively, the Lumix offers an electronic shutter, for example for silent release. The GX7 is also capable of interval shooting, with the time-lapse function taking photos at preset intervals that can be put together to form a film.

Every square millimetre on the top of the Panasonic Lumix DMC-GX7 housing is used: viewfinder, flash shoe, pop-up flash, shutter release, control wheel, video release and program selector wheel find their place here. [Photo: Panasonic]

In addition to photos with a maximum resolution of 16 megapixels in JPEG or raw format, the GX7 can also record videos in a maximum Full HD resolution of 1,920 x 1,080 pixels. The maximum frame rate is 50p, but for cinema feeling you can also switch down to 24p. The user can choose between MP4 and ACVHD progressive recording format. The sound is recorded in stereo, the Dolby Digital technology should provide better sound, a windscreen filter can be switched on. Panasonic also wants to have improved the video quality, and semi-automatic and manual exposure as well as touch autofocus are also available for film recordings. In addition, the Lumix offers a digital zoom for video recording that records at full resolution without interpolation thanks to the higher sensor resolution.

The housing of the Panasonic Lumix DMC-GX7 is made of a robust magnesium alloy. [Photo: Panasonic]

The GX7 is also capable of wireless image transmission. It has not only a WLAN module, but also NFC. All you have to do is hold a smartphone with the appropriate app up to the camera and the two devices exchange the WLAN settings for image transmission. The GX7 not only sends its pictures to smartphones and tablets, but also optionally to a PC, via DLNA to a television, for example, or to the Internet in social networks, picture sites, Youtube or the Panasonic cloud. In addition, the GX7 can be remotely controlled via WLAN from a smartphone or tablet, giving the user access to numerous settings. The captured photo can be transferred directly to the smartphone or tablet. The user can also benefit from the smartphone’s GPS, which can be used to add geotags to the photos taken.

Ergonomics and workmanship

When you first make contact with the Lumix GX7, you involuntarily think: “It’s actually wide”. But a glance at the technical data quickly makes it clear: this must be an optical illusion. Although the GX7 is a few millimeters wider and higher than a comparable Sony NEX6, it looks much more voluminous. Responsible for this impression is the lens with the bulky designation G Vario 14-42/1:3.5-5.6 II Asph Mega O.I.S., with which our test camera was equipped and with which the GX7 is also offered as a set. It has a very small diameter and makes the camera appear larger than it actually is. Equipped with this standard zoom, the GX7 presses about one pound on the scale. This makes it easy to carry, but also comfortable to hold. A neatly shaped and non-slip grained handle contributes its rest to the fact that the GX7 can be held safely – if necessary also only with one hand. This is ultimately more important than a smart design, especially our pure black test model looks rather sober. The GX7 is also available in a version with silver top and bottom, which gives it a retro look.

The Panasonic Lumix DMC-GX7 is available in silver-black, and also in black from September 2014. [Photo: Panasonic]

Panasonic has concentrated the control elements on the right outside of the housing. They can be easily reached with the thumb or index finger and are largely placed in such a way that hardly anything can be accidentally adjusted. The small pushbuttons should only be slightly larger. But you can overlook that, because you don’t need them that often anyway: The Lumix GX7 features a touch-sensitive display that makes it easy to control the camera. This screen has a fine resolution of over one million pixels and can be tilted horizontally upwards and downwards by around 45 degrees. Touch control, a decent number of buttons and knobs and the practical quick menu all contribute to the fact that the main menu rarely has to be tried in everyday life. If you do, you’ll find it easy to find your way around. Panasonic has divided it exemplarily into five main registers, each of which is then divided into sub-registers. This structure prevents you from having to scroll through long lists – practically every parameter can be called quickly.

The GX7 with its electronic viewfinder (EVF) offers a really good alternative for those who don’t like to control the viewfinder image by stretching out their arm. It is placed on the far left outside and protrudes a good deal over the rear housing. So you don’t run the risk of flattening your nose on the display – at least not if you look into the viewfinder with your right eye. Almost unique is, EVF can be swivelled up to 90 degrees. In this way you get a kind of shaft finder, which enables a very precise viewfinder image control, especially with shots close to the ground. With its 2.76 million pixels, the EVF of the GX7 has an extremely fine resolution. So fine that the detail reproduction hardly differs from the classic optical viewfinder. This is due to the special “field sequence display” technology: Each pixel shows one of the basic colours red, green or blue in a rapid change. So fast that the eye only perceives a single color value. This works really well, the EVF’s color rendering is very close to the colors of the shot, according to Panasonic the EVF almost covers the “Adobe RGB” color space. With these beautiful colors, it’s easy to accept that the EVF doesn’t react so quickly to changes in the viewfinder image. When the GX7 is panned quickly, the viewfinder image appears blurred, but stabilizes instantly once the camera has come to rest again. In terms of resolution, contrast and colour reproduction, this EVF is certainly one of the best currently available.

However, spectacle wearers will not like this too much: The exit pupil is calculated for an interpupillary distance of 17.5 millimetres – you can’t get that close to the viewfinder with glasses. If the eye remains further away, however, the viewfinder image disappears in a dark tube and can no longer be completely overlooked. At least Panasonic has provided the EVF with an extensive diopter correction, so that you can push the glasses into your forehead if necessary.

The autofocus of the Panasonic Lumix DMC-GX7 works at a frequency of 240 frames per second, but it is not only very fast, but also light-sensitive. -4 EV are sufficient for focusing, which corresponds to a starry night. [Photo: Panasonic]

 

While most of the buttons and switches on the right side of the GX7 are crowded, the connectors for USB and HDMI cables, as well as the optional remote control, are located on the left side under a simple plastic flap. The very high-quality magnesium-aluminum case of the GX7 not only looks a bit out of place, but is also cumbersome to open. For this you first have to fold down the display a bit. The bottom of the camera is clean and tidy. Here there is a tripod thread that sits neatly in the optical axis, as well as a combined battery and memory card compartment. It sits far enough away from the tripod thread so that mass storage and energy dispensers remain accessible even when the quick-release plate is attached. On the upper side the camera looks a little more messy, the big shutter release stands out clearly here. This, however, is very much in line with ergonomics, as the control elements are easy to feel thanks to their unique shape.

The Panasonic Lumix DMC-GX7’s live MOS sensor has a resolution of 16 megapixels and, compared to the GX1, has a ten percent higher sensitivity and a 25 percent better signal-to-noise ratio. [Photo: Panasonic]

Equipment

If you browse through the main menu of the GX7, you’ll quickly see how extensive the camera’s range of functions is. This may deter beginners and less experienced photographers at first – but don’t worry: Panasonic has equipped the GX7 with clever fully-automatic functions that take practically everything off your hands. If you want, you can override the exposure meter, white balance and the aperture value to control the depth of field in the “intelligent automatic” mode. Whether the on-board flash is used or not is always decided by the photographer: the GX7 only flashes when the small flash unit has been manually unfolded. In addition to the fully automatic mode, the GX7 offers over 20 motif programs to choose from – which is perhaps a little too much of a good thing. The same goes for the creative effects, where you are spoilt for choice between 22 options from “star filter” to “miniature effect” to “bleach bypass”.

Experienced photographers who want to adjust their camera to suit their taste will hardly miss a single opportunity with the GX7. The equipment list is so extensive that you almost have to call it “complete”. For example, the functions for taming high subject contrasts. This is left to the intelligent tonal value correction i.Dynamik, for example. Alternatively, the GX7 offers HDR auto, which combines three differently exposed shots into one image with perfectly drawn depths and highlights. As a further possibility, the image processor can be given an editable tonal value curve; it determines to what extent depths and/or highlights are raised or lowered.

The flash system of the GX7 is very mature. It goes without saying that it comes with functions such as long-time sync or flash on the second shutter curtain. However, the very short flash sync time of 1/320 s with the on-board flash and still short 1/250 s with an external system flash unit is not a matter of course. The functions for controlling a wirelessly connected system flash are exemplary. The GX7 can address up to three groups and each group can be configured individually. However, the camera is somewhat stuttering when it comes to flash exposure correction – it can only be called up in the depths of the main menu and cannot be included in the quick menu nor can it be assigned to a function key. That’s a shame, because (like so many cameras) the GX7 is too good at fill-flashing in backlight situations and therefore does not make the main subject look nice in its surroundings.

The GX7 takes 9.3 photos per second (fps) in JPEG and 8.0 fps in raw format, making it the ideal camera for fast continuous shooting. She shows a lot of staying power, 25 JPEG shots are possible at the high tempo, but in raw format there is already an end to the spurt after nine photos. Afterwards it goes on in the endurance run all the more leisurely with 2.1 fps in JPEG and slow 0.4 fps in raw. In practice, however, the high endurance in sprinting is probably more important than the comfortable pace in endurance running. Small flaw: In high-speed series, the GX7 does not display a Live View image, instead the last shot appears in the viewfinder for a brief moment. This is particularly annoying with pullers, here the motif wanders easily out of the frame. Those who want to avoid this can also shoot series with viewfinder image control, but then the frame rate drops to around 3.8 fps. At this reduced frame rate, the GX7 can then also adjust the focus (in high-speed series, it is fixed to the first frame). However, the tracking autofocus has some problems, not all shots were sharp in practice.

The tracking AF, on the other hand, has no problems with video recordings. The GX7 films with a maximum resolution of 1,920 x 1,080 pixels (i.e. in full HD) at a high data rate of 28 Mbps. When filming, practically all options are available that are also available for photos. For example, you can set an aperture to control the depth of field, and the GX7 will adjust the exposure time accordingly. Panasonic offers power zoom lenses specially designed for smooth zoom drives, such as the Vario PZ 45-175/4.0-5.6 or the very compact Vario PZ 14-42/3.5-5.6. Photos can also be taken simultaneously with video recording. Alternatively, the GX7 allows individual images to be extracted from a video in playback mode. Otherwise, the subsequent image processing options are somewhat limited: Cutting pictures, combining them into a stop motion film – that’s it.

The possibilities offered by the WiFi function of the GX7 are very generous (see also the photo tip on the subject in the links). First of all, it has NFC on board, so smartphones and cameras can be connected without having to enter SSID and password. Once connected, the GX7 sends recordings to the connected device and can also be controlled remotely from a smartphone or tablet. All you need is the free “Panasonic Image App”, which offers a pleasantly large range of functions. The GX7 also takes the GPS data from a connected mobile device – so the camera itself can do without a GPS receiver. Of course, the GX7 can also transmit pictures and videos to a PC or a TV set in the network.

Lens

For our test, the Lumix GX7 was equipped with the standard zoom “G Vario 14-42/1:3.5-5.6 II Asph Mega O.I.S.”, which covers a focal length range of 28 to 84 millimetres in 35mm. The appearance of the small zoom is unspectacular, tube and bayonet are largely made of plastic. This economy measure at least benefits the weight, the lens only presses a little more than 100 grams on the balance. However, Panasonic has not cut back on technology: nine lenses in eight groups take care of the imaging, and two lenses are also aspherically shaped. In addition, the lens is equipped with an optical image stabilizer.

As an alternative to the optical image stabilizer, Panasonic is using a sensor-based stabilizer in the GX7 for the first time. It is used when a non-stabilized lens is attached to the camera. These can be not only Micro-Four-Thirds lenses, e.g. from other manufacturers, but also lenses that are connected to the GX7 via an adapter. The GX7 is also very flexible when adapting external optics thanks to its small overprint of around 19.6 millimeters, making it ideal as a system carrier for Leica M lenses.

When it comes to autofocus, Panasonic relies on the GX7’s very accurate, but in principle rather slow contrast measurement. But all theory is gray, the Lumix GX7 is a sharp-edged machine. The shutter release delay including automatic focusing from infinity to two meters is a maximum of 0.2 seconds. Hardly any other camera is that fast, not even a professional DSLR! The trick with which Panasonic makes the autofocus legs is no longer completely new, but still amazes: When focusing, the GX7 reads the sensor signal at a very high rate of 240 Hertz. In addition, the processor and servomotors are apparently capable of reacting quickly enough. The process even works with tracking AF, which will also please video filmmakers: The GX7 adjusts the focus at lightning speed and with hardly any pumping. With automatic facial recognition, the GX7 keeps portraits in focus once they are detected. If you want to focus manually (or need to do so with an adapted lens), the GX7 is the perfect tool for you. One is focus peaking, which highlights the edges of the subject in color within the focal plane. And on the other hand there is a very widely adjustable focus loupe. The Lumix GX7 also has an AF/MF switch, so you can switch between autofocus and manual focusing in a flash.

Picture quality

The Lumix GX7 digitizes the image using an image sensor in Four-Thirds format with 16 megapixels resolution. With only 25 percent of the surface area of a 35mm film, this image converter is thus quite highly integrated, which theoretically entails disadvantages for the signal-to-noise ratio as well as the input dynamics. Among other things, Panasonic wants to counter these disadvantages with a new design in which larger photodiodes and special microlenses enable significantly higher luminous efficacy.

 

Even at low ISO levels, the GX7 doesn’t exactly shine with an outstanding signal-to-noise ratio, but the critical limit of 35 dB is only just undershot at ISO 3,200. ISO 3.200 is also the limit up to which luminance noise remains uncritical. In practice, the brightness noise remains unproblematic even at even higher ISO levels, because the GX7 shines with a very fine grain up to the maximum sensitivity of ISO 25,600. It also has the particularly annoying color noise firmly under control, color disturbances are effectively suppressed over the entire sensitivity range. However, not everything that shines in these measured values is gold: even beyond ISO 200, texture sharpness decreases continuously, initially only moderately, then stronger beyond ISO 800. This is a clear indication that noise suppression intervenes early and vigorously. A finding that is confirmed when looking at the images: Photos with ISO 1.600 already look much flatter and less detailed than those with the basic sensitivity of ISO 200. In short: the noise reduction of the GX7 exaggerates it a bit in the standard settings. Fortunately, it can be configured individually, and custom noise reduction is also possible with raw files.

There’s nothing to criticize about the GX7’s input dynamics. It processes a contrast range of almost eleven f-stops over practically the entire sensitivity range – an excellent result! The GX7, on the other hand, finds it a bit difficult to differentiate between the finest brightness gradations, but the output tonal range remains good up to ISO 1,600. The tonal value curve is tuned rather crisp by default, but can be adjusted as desired. Panasonic should continue to improve the color reproduction – here the GX7 remains in the inglorious tradition and shifts cyan and orange tones strongly in the direction of warm. On average, however, the color deviations are alright, although other cameras in their price range take it a little more precisely.

The bottom line is that the performance of the new image sensor coupled with the internal image processing of the GX7 are quite convincing – especially as the latter can be adapted to your own ideas in great detail. But what does it look like when the price-optimized set lens comes into play? Not bad at all: The sharpness runs nicely evenly over the entire image field, especially if something is stopped down. Vignetting is measurable, but is not noticeable. The G Vario 14-42 is also good-natured when it comes to chromatic aberration; only in the outermost corners of the picture can colour fringes on contrasting edges be a bit annoying. However, the price-optimized lens doesn’t cut a particularly good figure when it comes to resolution.

In the best case it only manages 40 line pairs per millimeter (lp/mm), only in the center of the image. Many a high-quality compact camera can easily keep up. Towards the edges of the image, the resolution decreases again considerably, especially in the wide-angle and telephoto range, the lens conceals fine details that the sensor could effortlessly reproduce.

The bottom line is that the Lumix GX7 delivers impressive image quality, but not necessarily with the factory default. However, it has the disadvantage when very high ISO levels are required, even with optimum configuration, a visible loss of quality can be expected from ISO 3,200 onwards at the latest.

Bottom line

The Lumix GX7 undoubtedly deserves a place on the Olympus of mirrorless system cameras. Its range of functions is outstanding, and the camera can also be customized very widely. A real highlight is the electronic viewfinder, which provides very fine resolution, covers a wide colour space and also reproduces high motif contrasts in a comprehensible way. The unique feature is that the EVF can be swivelled upwards, making it ideal for shooting close to the ground. It’s just a pity that spectacle wearers don’t enjoy the great EVF, the exit pupil is too close to the eye for that. The GX7’s body is impeccably crafted, the camera sits comfortably in the hand and is easy to operate thanks to the touch screen and the many freely assignable function keys. In addition, the camera shines with a high serial frame rate as well as an ultra-fast autofocus. If there is any reason for criticism at all, then it is at most the picture quality. The rather small Micro-Four-Thirds sensor has some minor problems with image noise, which the image processor fights too vigorously. Nevertheless, the GX7 delivers really useful image results up to quite high ISO 3,200 if you take some of the throttle off noise reduction. The price-optimized standard zoom is also doing well, only the resolution should be better. If you’re looking for a compact system camera and don’t want to compromise, you won’t find many alternatives to the Lumix GX7 at the moment.

Firmware Update 1.2 for the Panasonic Lumix DMC-GX7: New Features

Panasonic has released new firmware version 1.2 for the mirrorless Lumix DMC-GX7 system camera. As usual with Micro Four Thirds, the update can be found in a special download area that combines firmware updates for lenses and camera bodies of the two founders Panasonic and Olympus. The update for the GX7 brings two new features. On the one hand, compatibility with the new ultra-flat zoom lens Lumix G Vario 12-32 mm 3.5-5.6 Asph. O.I.S. is improved, especially with regard to manual focusing. On the other hand, the Fn key can now be assigned another function: Flash exposure compensation.

The firmware update for the Panasonic Lumix DMC-GX7 ensures that the Lumix G Vario 12-32 mm 3.5-5.6 Asph. O.I.S. can be focused better manually. [Photo: Panasonic]

Panasonic Lumix DMC-GX7 Datasheet