Panasonic Lumix DMC-GH2 at a glance:

  • 16.05-million-pixel Four Thirds Live MOS sensor
  • 3in articulated touchscreen
  • Full HD (1920×1080-pixel), 60i video capture
  • New Light Speed AF system
  • Street price around £800 including 14-45mm kit lens

When the Lumix DMC-GH1 was released in March 2009, it was only Panasonic’s second Micro Four Thirds camera. It is easily distinguished from the preceding DMC-G1, as the GH1 uses a slightly larger sensor and has the ability to shoot HD video footage.

Yet with the introduction of the G10 and G2 models, the lines between Panasonic’s G-series cameras became a little blurred. These cameras are aimed at entry-level and enthusiast photographers but, like the GH1, both are capable of shooting video – the G2 even has a touch-sensitive screen.

The Lumix DMC-GH2 re-establishes the G-series hierarchy by employing the best features from each camera, such as the touch-sensitive screen, while also introducing some new features of its own.

These include a sensor with an effective resolution of 16.05 million pixels and a powerful processing system that enables more advanced video capture and faster contrast-detection AF. It also adds the option of capturing 3D images via Panasonic’s new H-FT012E 3D lens.

With this host of new features, the GH2 is at the pinnacle of Panasonic’s G series, but is it the best Micro Four Thirds camera currently available?

Features

Despite the touchscreen bringing a new dimension to how the Lumix DMC-GH2 handles, it is the processing components tucked away inside that really steal the show. These are centred around the new 18.31-million-pixel Live MOS sensor, which has an output of 16.05 million pixels. The idea behind the larger sensor is the same as that on the GH1, where the 14-million-pixel sensor provides a maximum output of only 12.1 million pixels. For more details on this, see Features in use on page 46.

Data from this 18-million-pixel sensor is processed by a new Venus FHD image processor, and an exclusive version of Panasonic’s vMaicovicon image controller. These new internal processing improvements are designed to process data signals at high speed, primarily for the capture of high-definition video.

Beyond processing and capturing video footage, the fast, progressive scanning rate of this processing system also benefits the GH2’s contrast-detection AF system. It is able to double the drive speed for the AF processing from 60fps to 120fps, meaning that the data from the sensor can be read and analysed more quickly, and contrast detection can take place much faster than we have previously been used to. In fact, the new AF system is so quick that Panasonic calls it Light Speed AF, and claims it is the world’s fastest.

When I reviewed the Panasonic Lumix DMC-G2 (AP 15 May 2010), I was impressed with its new touchscreen technology and it is no surprise to see its inclusion in the GH2. The main screen allows access to the camera’s quick menu, and settings can be changed by simply touching the screen.

However, it is the Touch AF and Touch Shutter that I found most useful in the G2, as these two features allow you to select the point of focus by simply touching the on-screen image; the latter function will also then fire the shutter to take an image. So, when I found out that I would be testing the GH2, I was particularly excited about seeing how these features would work with the new Light Speed AF.

Build and Handling

Anyone familiar with the Panasonic Lumix DMC-GH1 will feel immediately at home with the GH2, as it is virtually identical. Like the GH1, it has a miniature DSLR-style design with a reassuringly solid plastic body and contoured handgrip.

The first noticeable change is the repositioning of the control dial from the grip at the front of the camera to the top right of the rear. For me, this had little effect on how the camera handled, but whether you like it or not will come down to personal preference.

The repositioning of the control dial means the direct movie record button is now on the top of the camera, as on the G2. Unlike the G2, however, the iAuto button on the top of the camera has been replaced with one of three function (Fn) buttons.

The top button is set by default to activate iAuto, but there are numerous other options that can be applied to this, or the other two function buttons. The other function buttons are the left and down directional controls on the rear, which are by default assigned to the metering modes and the film styles.

The only other difference between the GH2 and its predecessor is the secondary switch on the AF point dial. This switch is positioned at the side of the dial and is used to shift between manual focus and continuous or single AF. This was also the case with the G2, and it makes the various different AF configurations quick and easy to access.

In fact, the overall placement of the buttons and dials on the GH2 makes it very clear and simple to operate. All the most regularly used features have dedicated buttons and can be found without having to enter the camera’s on-screen menu system.

The one major change in handling from the GH1 is the touchscreen. It is the same screen as found in the G2 and it works identically in the GH2. While many photographers bemoan touchscreens as unnecessary, fiddly and awkward to use, I have to disagree with them with regard to its use in the GH2. Touch-sensitive screens have moved on in leaps and bounds in recent years: the touchscreen of the GH2 does not require a forceful press like a railway station ticket machine, but rather just a slight touch.

However, the operation of the camera isn’t reliant on using the touchscreen. The quick menu also has its own dedicated button on the rear of the camera and the directional controls can be used to navigate the shooting options.

The GH2, therefore, provides the best of both worlds. For the more traditional photographer there are plenty of dials and customisable buttons for easy access, while the more tech-savvy user will no doubt make good use of the touchscreen for quick assess to every shooting feature.

Metering

Image: The GH2 has a good dynamic range for a Micro Four Thirds camera. A lot of detail can be recovered, particularly from shadow areas, although if pushed too far noise does become visible

Like all the other Panasonic Lumix G-series cameras, the GH2 has a 144-zone multi-pattern metering system. The way this system judges exposures seems much the same as in other G-series models. On the whole, I found that the evaluative metering mode produced images suitable for printing or display straight from the camera.

Images taken under bright blue skies are well exposed for both sky and foreground, and look particularly good when combined with the vibrant colour setting. Shooting landscapes on an overcast day tends to produce exposures that prioritise the sky, making sure there is some detail and very few, if any, burnt-out highlights.

The downside to this is that it leaves the actual landscape and anything in the foreground looking slightly underexposed. However, this can easily be adjusted using exposure compensation. In fact, I feel the underexposure is actually a good thing, as most photographers would prefer to retain detail in the sky and use editing software to lighten a dark foreground.

Switching to spot metering mode and photographing a grey card confirms that the GH2 does slightly underexpose. Measuring the RGB values of the grey card in Adobe Photoshop gives a reading of around 118, whereas 128 is an exact midtone.

Generally, photographers, and videographers for that matter, will be happy with how the GH2 meters most scenes. After a while you get to know how it will meter and can alter the exposure accordingly.

With evaluative, centreweighted and spot metering, as well as exposure compensation and Intelligent D-Range Control, there are plenty of different options to ensure that images look exactly how you want them.

Dynamic Range

As the Lumix DMC-GH2 has a tendency to underexpose images slightly to minimise burnt-out highlights, it often appears that there are large areas with no detail. However, many of these areas are not completely black and there is still detail that can be recovered.

That said, there is a limit to how much detail can be retrieved before image noise becomes an issue. Opening a JPEG file in Adobe Camera Raw, I was able to increase the exposure by around 2EV to recover detail. Beyond this, colour and luminance noise starts to become visible in shadow areas, even at fairly low ISO sensitivities.

The DxOMark website (www.dxomark.com) measures the dynamic range of the GH2 as 11.3EV, which is slightly less than the previous GH1’s 11.6EV. This minute difference is most likely the result of the GH2’s new sensor being more densely populated. Nevertheless, the dynamic range is still very good for a Micro Four Thirds camera – the G2 only measured 10.3EV in the same test.

The GH2’s dynamic range is on a par with, or is only a little less than, most current DSLRs with APS-C-size sensors. The fact it underexposes slightly to preserve highlight detail means there is still plenty of image data that can be adjusted, particularly when capturing images as raw files. If you are more accustomed to shooting JPEG files, then the in-camera Intelligent D-Range Control has various settings that adjust the image to help recover detail in highlight and shadow areas.

Autofocus

When I first tried a pre-production version of the GH2, in a meeting with Panasonic back in October 2010, I was genuinely excited about the speed of the new contrast-detection AF system. However, I did wonder how it would cope in a real-world test situation.

Thankfully, the new Light Speed contrast-detection AF lives up to its initial promise. Panasonic claims that it snaps from its minimum focus distance to infinity in 0.1 seconds, and while I had no way to accurately test this, after using the GH2 I have no reason to doubt the claim. In AF-S mode, using the 14-140mm f/4-5.8 lens, the camera snaps into focus as fast, if not faster, than most phase-detection systems.

But before you all start selling your DSLRs and buying GH2s, the camera does have a weakness – in single-point continuous AF, contrast detection doesn’t work as well as phase detection and still has to move back and forth to find the point of focus. This slows the focus and causes it to miss the exact area you want, although that is not to say that continuous focus isn’t worth using. The AF tracking and face detection modes work well with moderately moving subjects, so it is more than suitable for use at social events, with children playing and even some sports. If you want to capture faster and less predictable movement, such as a football or rugby match, then a camera with phase-detection AF is still the better option.

Touch AF adds a new dynamic to focusing. It allows you to simply touch the area on screen that you wish to focus on. Even better, though, is the Touch Shutter function. This not only focuses when you touch the screen, but also fires the camera’s shutter and captures an image. The process happens almost instantly, but those concerned that touching the screen will create a slight movement should not worry.

The screen is sensitive enough that it doesn’t require a firm press, and while there is a little more movement compared to pressing the shutter button, unless you are shooting using a telephoto lens or a slow shutter speed you shouldn’t notice any camera shake.

I’m pleased that the AF system of the GH2 lived up to my initial expectations. It goes a long way to proving that contrast-detection AF, when implemented correctly, can be just as fast as phase-detection AF.

It may not be able to keep up with a phase-detection system when it comes to the continuous focusing required for sports photography, but the GH2 really isn’t designed for that type of application.

It’s not just for stills photography that the AF system excels; it also plays a major part in the camera’s video capture capabilities, but more on this later.

White Balance and Colour

Anyone who already uses a Panasonic G-series camera will be familiar with the way the GH2 renders colours. In its default standard colour, or ‘film style’ as it is called, colours are realistic, but many will prefer their images with a little more impact. Thankfully, the GH2 is laden with different colour modes, and they are all genuinely useful.

Among the standard options are the vibrant and dynamic settings. Of these, the vibrant setting adjusts the saturation of the colours in the image, whereas the dynamic setting increases the level of contrast and in turn makes the colours look more saturated than in the standard film-style mode.

The smooth setting keeps the realistic colours of the standard setting, but increases the contrast to add a little more impact. The nostalgic setting, meanwhile, decreases saturation and contrast.

One option that will be of interest to videographers is the cinema setting. This appears to darken the image and prevent blown-out highlights while increasing the contrast a little and leaving the saturation looking fairly natural. There is also a choice of three different black & white settings.

Each of the film presets can be adjusted, and there is also the option to save two user-defined film styles. If you can’t decide on the style you wish to use, there is a multi-film mode that allows three different styles to be selected. These will be applied in succession each time you take an image. While multi-film is a useful mode, it would be even better if it required just one press of the shutter to take an image and save it three times with different styles.

The GH2’s AWB does a very good job in almost every condition I tested it under. When using it under household tungsten lighting it just took the edge off the colour cast, while the tungsten setting produced a neutral white balance. Which you prefer is down to individual taste, but if you demand absolute precision then there are also custom and manual settings available.

Image: At its native sensitivity of ISO 160, the GH2 captures a great deal of fine detail and is certainly on a par with similarly specified DSLRs with APS-C-size sensors 

Resolution, Noise and Sensitivity

With 16.05-million-pixels, the GH2 has an impressive resolution for a Micro Four Thirds system camera. In raw mode, images can be adjusted so that a resolution of around 26 can be achieved at the native sensitivity of ISO 160. However, JPEG images taken with the camera’s default settings only achieve a resolution of around 24.

The 16.05-million-pixel sensor does seem on the verge of overpopulation for its size. Luminance noise is visible at ISO 200, although it is not significant and is easily removed from raw images. As the sensitivity increases, luminance noise starts to have more of an effect, and it becomes an issue at around ISO 800.

Chroma noise also starts to creep in at around this point, although it is also visible at lower sensitivities if shadow areas are lightened too much. Thankfully, the chroma noise is easily removed from raw images at all but the highest sensitivity settings.

At the maximum ISO 12,800 sensitivity, luminance noise is quite severe, which causes a significant loss in detail resolution. However, overall, raw images from the GH2 have among the best detail resolution of any compact system camera.

Resolution and noise
These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using a Panasonic 14-140mm f/4-5.8 lens. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.

Viewfinder, LCD, Live View and Video

Image: In overcast conditions, the GH2 tended to underexpose images. However, it is possible to brighten raw images and still retain detail in the sky

Although the 3in articulated, 460,000-dot screen of the GH2 is identical to that used in the GH1, there has been an upgrade made to the electronic viewfinder (EVF). It is a slightly larger, 1,533,600-dot equivalent LCD viewfinder, offering 100% coverage. Like the multi-aspect sensor, this larger LCD viewfinder is used to ensure that the display is still of a high resolution when alternative aspect ratios are used.

Although the rear LCD screen is good, a higher resolution 920,000-dot screen would have really complemented the GH2’s position as the pinnacle of the Panasonic G series, and put it on par with its APS-C-format competitors.

Of the two viewing methods, it is the EVF that really stands out. Anyone who is concerned that an EVF can’t match an optical viewfinder should try the one on the GH2.

The resolution is high, but more importantly the refresh rate is very fast, meaning there is no image lag, blur or wobble as the camera is panned. It is the best EVF I have used. It really does set the standard, although I expect most manufacturers to match it, or even better it, within the next 12 months.

What really sets the GH2 apart from Panasonic’s own GF2 and G2 models is its video mode. The powerful processor means that the footage is captured progressively, but can be saved in the broadcast-compatible interlaced format.

When saving video for PAL TV output, footage can be saved with the AVCHD file format at 1080i or 720p. However, for budding film makers there is a special cinema mode that saves footage at 1080p at 24fps, imitating the frame rate and look of shooting moving footage on film.

While all this is impressive, it is perhaps the variable frame rate that is one of the most interesting features. This allows the footage saved to be at 80%, 160%, 200% or 300% of the speed of the actual footage, which makes it great for slightly slowed or speeded-up movement.

Due to the powerful video-processing system, the continuous AF works well when panning slowly. Yet it is the single AF mode that really excels, with the ability to use touch AF to select the point of focus.

This allows the focus to be easily changed from foreground to background for a very professional-looking effect. The AF even slows down when you do this so that it doesn’t snap into focus, but rather moves steadily and slowly.

Multi-Aspect Sensor

Although the maximum output of the GH2’s sensor is 16.05 million pixels, the actual sensor has 18.31 million photosites. The reason for this is that the GH2’s sensor is actually slightly larger than a standard Four Thirds sensor.

The default aspect ratio of a Micro Four Thirds sensor is, of course, 4:3. Usually, any other aspect ratio a camera produces is merely a crop of this. For example, the maximum 4:3 image size of the GF2 is 4000×3000 pixels, and the 3:2 ratio is a crop of this, measuring 4000×2672 pixels. Note how the width is identical, but the height of the image has been cropped to produce the different aspect ratio.

However, the GH2’s larger sensor is able to produce a 4:3 image that measures 4608×3456 (15.9m) pixels, while 3:2 images are 4752×3168 (15m) pixels. Although the height of the image is different, the slightly larger sensor maximises use of the imaging circle so that 3:2 images are actually wider than the native 4:3 ratio.

The benefit of this is that images maintain a resolution that is still reasonably high. This can be seen by the difference in resolution when looking at 4:3 images and 16:9 images produced by the GH2 and GF2. There is roughly a two-million-pixel difference in the size of images when switching between 4:3 and 16:9 on the GH2. This means that 16:9 images have around 12.5% fewer pixels than the 4:3 images. However, the 16:9 images produced by the GF2 are more than three million pixels smaller than 4:3 ratio images. This is a 25% reduction in the number of pixels.

So, the multi-aspect sensor means that there is less reduction in image size when the aspect ratio is changed from the standard 4:3 ratio.

Our verdict

Despite the new 16.05-million-pixel sensor, it is the new high-speed, contrast-detection AF and video capabilities of the Panasonic Lumix DMC-GH2 that really make it stand out from its competitors. The superb EVF should allay the scepticism of those who have had concerns about switching to this technology.

It does have a few flaws, though. The image quality is clearly affected by the densely packed sensor, and luminance noise is often visible at low sensitivities. This shouldn’t be too much of an issue for most photographers, but it does make you wonder how much longer the Micro Four Thirds format will be able to compete against the new high-resolution APS-C-format cameras.

The touchscreen will appeal to a younger generation of photographers, and touch AF and touch shutter are genuinely useful. However, the best thing is that use of the touchscreen isn’t integral to the camera’s operation and the usual control buttons can be used.

At around £800 including the 14-45mm kit lens, the GH2 is reasonably priced, but to get the most from the camera I would recommend the slightly more expensive 14-140mm kit, which costs around £1,000.

Panasonic Lumix DMC-GH2 key highlights

Viewfinder sensor

This sensor detects when the camera is held up to the eye and automatically switches the screen off and the EVF on.

Articulated touchscreen

One of the major new features of the GH2 is the articulated 3in touch-sensitive screen.

3D still images

At the same time as the introduction of the GH2, Panasonic also announced the H-FT012 3D lens. The 3D images created can be displayed on compatible 3D television screens and displays.

Touch playback

It is not just for taking images that the touchscreen can be used. It is also employed in playback mode to quickly scroll, select and zoom in on images.

Histogram

The GH2 has the option of displaying a live histogram display on the screen. One advantage with this camera is that the exact position of the histogram on the screen can be selected by the user.

iAuto

Like other Panasonic cameras, the GH2 features an Intelligent Auto (iAuto) mode. In this mode, the camera automatically detects what you are trying to photograph and changes the settings accordingly.

Quick menu

Although the quick menu can be operated via the touchscreen, it can also be switched on using this button and navigated via the directional buttons below.

Function button

Of the three function buttons on the GH2, this one is the most useful as it is easily pressed while shooting.

The competition

 

Images: Panasonic Lumix G2, Sony Alpha 55 

The most obvious Micro Four Thirds competitor for the GH2 has to be Panasonic’s own Lumix DMC-G2. Both cameras have a very similar build and handling, but the G2 has a lower 12.3-million-pixel sensor, lower-resolution EVF and more limited video capture options. The more compact GF2 is also a good choice, and is similar to the G2 but does not feature a built-in EVF.

If video capture is a major requirement, the Sony Alpha 55 (or Alpha 33) may be a good choice. Their translucent mirror technology allows phase-detection AF to take place in video capture for fast and smooth focusing. The Alpha 55 also features a 16.2MP APS-C-size sensor, but in a larger body.