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Review: Panasonic G7

Introduction and features

Replacing the Panasonic G6, the G7 sits beneath the Panasonic GH4 in the company's line-up of compact system cameras. It's the smaller of the two SLR-like models, and is aimed at enthusiast photographers. It sits alongside the rectangular Panasonic GX7, and above the GF7, GM1 and GM5.

Every Panasonic interchangeable lens camera briefing recently seems to have started with the words "it's got the same sensor as the GX7", and that's also the case with the G7. This means the new camera has the same resolution as the camera it replaces, 16MP, but the sensor is newer (albeit still two years old). This sensor is coupled with the Venus Engine 9 processing engine found in the GH4 and, according to Panasonic, this combination produces the best image quality of any Panasonic camera. It also enables a native sensitivity range of ISO 200-25,600, with a low expansion setting of ISO 100. The G6 has a native range of ISO 160-12,800, with an expansion setting of 25,600.

The G7's Venus Engine has a quad-core CPU for faster processing, enabling full-resolution continuous shooting at an impressive 8fps (frames per second) in Single-AF mode or 6fps in Continuous AF mode. That's 1fps up on what the G6 can muster in each autofocus mode.

If you want to shoot at a faster rate you have to drop the image size to 8 million pixels – that's still large enough to make A4 prints – and use the 4K Photo modes to shoot at 30fps. This uses the G7's 4K video technology to shoot a sequence of images for up to 29 minutes 59 seconds, and you can then extract the 8Mp still images from the footage in-camera.

In 4K Burst Shooting mode shooting continues for as long as the shutter release is held down. In 4K Burst (Start/Stop) mode, however, recording is started with a press of the shutter release and is stopped by a second press. Meanwhile in 4K Pre-burst mode, sensor scanning starts as soon as the mode is activated, and the 30 frames before the shutter release is pressed are recorded along with 30 frames after, giving 60 images from the two seconds of recording.

These 4K burst modes can be used in any exposure mode, and in 4K Burst Shooting and 4K Burst (S/S) modes it's possible to use image ratios of 16:9 (3840 x 2160), 4:3 (3328 x 2496), 3:2 (3504 x 2336) and 1:1 (2880 x 2880).

The G7 can also record 4K MP4 movies at 100mb/s at up to 30fps in NTSC or 25fps in PAL. Full HD footage can be recorded in MP4 or AVCHD format at a range of frames rates.

Panasonic has also given the G7 the DFD (Depth from Defocus) focusing system first seen in the GH4. This system uses lens data and looks at the contrast of the scene at two different defocused images to help it calculate the correct focus point more quickly. As with the GH4, Panasonic claims this enables the G7 to achieve focus in just 0.07 sec, approximately half the time the G6 takes.

Although the G7 has Wi-Fi connectivity, in a surprise change from the G6 and in an effort to keep the price down, there's no NFC (near field communication).

Build and handling

Panasonic has given the G7 a more angular look than the G6 it replaces, and there are a couple of changes to the control layout. On the top plate, for example, there are two fairly large dials. The first of these surrounds the shutter release, and replaces the Function Lever on the G6, while the second is towards the back of the plate and within reach of your right thumb. They both feel well made, and the camera responds quickly to adjustments. The front dial is easier to use than the old Function Lever.

Over on the left side of the top plate is a new drive mode dial, similar to the one on the GH4. This dial has an option to select 4K Photo mode, with the three 4K options being selected in the menu by pressing the Menu/Set button at the centre of the navigation controls on the back of the camera.

As on the G6, the G7 has a vari-angle touchscreen, as well as an electronic viewfinder (EVF), for composing and reviewing images. With 2,360,000 dots the EVF has almost double the resolution of the G6's finder, and it's an OLED (Organic Light-Emitting Diode) unit. It provides a good, clear view with plenty of detail, although noise seems to sparkle in low-light situations.

Meanwhile the 3-inch screen has had a little boost up from 1,036,000-dots on the G6 to 1,040,000 on the G7. It's also very clear, and responds to touch quickly. Like most screens it suffers from reflections in direct sun, but when its brightness is set to the maximum it's usually still possible to see enough information to compose an image if you can't use the viewfinder. It can, however, be hard to see the thin line of the electronic level switch from yellow to green to indicate that the camera is level.

I find Panasonic's Touch Pad AF system very useful, as it enables you to set the AF point with your finger on the screen while looking through the viewfinder; however, as a left eye user it's essential that I swing the screen out to the side to avoid setting the AF point with my nose.

Six of the G7's physical buttons and five virtual buttons on the screen are customisable, which means you can set up the camera to suit how you like to shoot. It's not possible to assign a button to turn off or activate Touch Pad AF quickly, which I would find useful in some situations, and although the Quick Menu can be customised, there's no customisable page for the main menu, which would also be useful for grouping together the most commonly used features.

It takes a little while to get used to shooting in 4K Photo mode, especially Pre-Burst because you feel like you've missed the action when you press the shutter release, but it works well. It's easy to extract the 8Mp images in-camera: hitting the 'up' navigation key reveals all the shots in the sequence, and you can then scroll quickly through until you find the most interesting images. Pressing the Set/Menu button gives you the option to save the selected frame as a JPEG.

While the G7 is fairly lightweight and feels like an entry-level camera, its plethora of buttons and dials make it more suited to use by experienced photographers. It also has a large grip with a textured coating that makes the camera comfortable and secure in your hand. If you're used to handling cameras like the Fuji X-T1 or X-T10, the G7 is going to seem quite insubstantial by comparison, but the controls are well arranged and responsive.

Performance

When I tested the Panasonic GX7 back in August 2013 I found that it produced high quality images; noise was controlled well up to about ISO 6400, but speckling was visible at 100% in images taken at ISO 800 and higher. The G7 follows the same pattern, which isn't surprising given that it has the same sensor.

When all noise reduction is turned off coloured speckling is visible at 100% in raw files taken at ISO 1600 and higher. At the default settings, simultaneously captured JPEGs have no chroma noise, but there is some softening of detail, and luminance noise is visible at 100%, with some areas looking quite mushy. While some ISO 12,800 images may make good A3 (11.7 x 16.6-inch) prints, others are best kept to A4 or smaller (8.27x11.7), and I would avoid using the top (ISO 25,600) setting where possible.

Panasonic's G-series cameras generally have very good metering and white balance systems, and the G7 is no exception. There were a few occasions during this test when a little exposure compensation was required, but on the whole the G7's Multi Metering system copes very well with a range of lighting situations. It does a great job in situations where some other cameras struggle, and its dynamic range is good, so highlights don't burn out too abruptly. Similarly, the automatic white balance system can usually be relied upon to produce natural-looking images.

Although the G7's Tracking AF system doesn't respond quickly enough for fast-moving subjects, if you keep the active AF point (or area) over the subject in 1-Area or Custom Multi mode with Continuous AF mode selected, in decent light it usually gets the subject sharp and keeps it in focus.

In normal daylight conditions and Single AF mode the camera focuses the lens very quickly, and it usually maintains a good speed even in very low light conditions, although some backwards and forwards adjustment is sometimes visible.

Video footage and 4K Photos follow the same pattern as the full-resolution stills, with generally good exposure, pleasant colours and good detail, although in Continuous AF mode there's occasionally a slight shift in focus away from the subject, which detracts from the final footage.

Helpfully, in 4K Photo mode the camera saves the footage that still images are extracted from, so you can have the best of both worlds. It's worth remembering that shooting upright format images results in incorrectly orientated video footage.

Panasonic's 4K Photo modes present some interesting creative options, enabling you to capture high-speed action easily. However, as the autofocus system operates in video mode it's quite slow, and isn't really suitable for shooting subjects that move towards or away from the camera. It's ideal for shooting action that takes place in one location though – a juggler, for example, or the movement of water over a object.

Lab tests: Resolution

We chose three rival cameras to the Panasonic G7 to see how it measured up in our lab tests: the Fuji X-T10, Olympus OM-D E-M10 and Sony A6000.

We carried out lab tests on the G7 across its full ISO range for resolution, noise (including signal to noise ratio) and dynamic range. We test the JPEGs shot by the camera, but we also check the performance with raw files. Most enthusiasts and pros prefer to shoot raw, and the results can often be quite different.

Panasonic G7 resolution charts

We test camera resolution using an industry-standard ISO test chart that allows precise visual comparisons. This gives us numerical values for resolution in line widths/picture height, and you can see how the G7 compares with its rivals in the charts below.

JPEG resolution analysis: The G7's 16Mp Four Thirds-type sensor gives a very good account of itself throughout the sensitivity range, even coming close to the 24Mp Sony A6000 for detail resolution.

Raw (converted to TIFF) resolution analysis: When raw files are converted using the supplied Silkypix software with no noise reduction applied, the level of detail falls a little behind that of the JPEG files; a bespoke conversion can draw out more detail.

Lab tests: Dynamic range

Dynamic range is a measure of the range of tones the sensor can capture. Cameras with low dynamic range will often show 'blown' highlights or blocked-in shadows. This test is carried out in controlled conditions using DxO hardware and analysis tools.

Dynamic range is measured in exposure values (EV). The higher the number the wider the range of brightness levels the camera can capture. This falls off with increasing ISO settings because the camera is having to amplify a weaker signal. Raw files capture a higher dynamic range because the image data is unprocessed.

Panasonic G7 dynamic range charts

JPEG dynamic range analysis: The Olympus OMD E-M10 captures the highest dynamic range for most of the sensitivity range, followed by the Sony A6000. The G7 compares more favourably with the other cameras at higher sensitivity settings.

Raw (converted to TIFF) dynamic range analysis: Up to and including ISO 6400 the G7 has an impressively wide dynamic range, indicating that images have a wide range of tones and will withstand a fair degree of manipulation.

Lab tests: Signal to noise ratio

This is a test of the camera's noise levels. The higher the signal to noise ratio, the greater the difference in strength between the real image data and random background noise, so the 'cleaner' the image will look. The higher the signal to noise ratio, the better.

Panasonic G7 signal to noise ratio charts

JPEG signal to noise ratio analysis: The G7 competes well with the other cameras, indicating that noise is controlled well in JPEG images.

Raw (converted to TIFF) signal to noise ratio analysis: The G7 puts in a very impressive performance at lower sensitivity settings, indicating that noise is controlled very well and images are clean.

Verdict

It's unlikely that G6 users will feel tempted to upgrade to the G7, and some may feel that the changes brought by the new camera are a little pedestrian and predictable. Nevertheless, the G7 is a very capable camera that produces high-quality images. It also showcases a feature that's likely to become more relevant to photographers over the next couple of years – 4K recording and the ability to extract 8Mp still images.

While the 4K Burst Shooting and 4K Burst (Start/Stop) modes may seem the most practical uses of this technology, experienced stills photographers who are used to timing shots carefully may be more attracted to 4K Pre-burst mode. This mode records at 30 frames per second for just two seconds, one before the shutter release is pressed and one after, capturing 60 images in total. This should be sufficient to capture the desired bit of the action, and it provides scope for selecting the perfect moment/expression without giving the photographer hundreds of images to scroll through to find the ideal shot.

4K Burst (Start/Stop) mode is especially useful for solo photographers shooting dynamic scenes such as water being poured over an object or subjects being dropped. With the camera mounted on a tripod, recording can be started before the photographer creates the movement in the scene, and once the action has played out recording is stopped with a second press of the shutter release.

One downside to using 4K Photo mode is that it turns a 16Mp camera into an 8Mp camera. However, according to Panasonic we can anticipate 8K recording with 33Mp stills by the time of the Tokyo Olympics in 2020 – that's going to take a huge leap in sensor technology from Panasonic.

We liked

The G7 has all the features we like in a compact system camera; a vari-angle touch-sensitive screen, a high-quality electronic viewfinder and a snappy autofocus system, along with a decent sensor. As a member of the Micro Four Thirds family there's also an extensive collection of lenses, from Olympus and Panasonic as well as some third-party manufacturers.

We disliked

While it has all the controls we'd expect, the G7's build quality is lacking in comparison with Fuji's X-series and Olympus's OM-D range of compact system cameras. It's not badly constructed, but it has a lightweight and plastic feel that won't entice enthusiast photographers. The autofocus system is excellent for shooting still subjects, but it struggles to follow fast-moving objects around the frame unless you're able to keep the active AF point in the right position.

Verdict

Although it lacks any real wow factor, the Panasonic G7 produces high-quality 16Mp images and offers one of the most well-rounded feature sets in its field, with a high-quality OLED viewfinder, a vari-angle touchscreen and Wi-Fi connectivity. Some photographers are dismissive of vari-angle screens and touch control, but both can promote creativity by encouraging photographers to shoot from a wider range of angles and look for a different perspective. Similarly, the 4K Photo modes extend creativity and inject a bit of extra fun into your photography – albeit at the cost of a halving of image size.

from TechRadar: Technology reviews http://ift.tt/1M7Ujsk