Thanks to its healthy selection of external controls, very little of the GH3 has to be controlled by interacting with the camera's software interface. Many secondary settings (such as image size and AF point mode) can be changed using the camera's Q.Menu, rather than delving into the main menus.
By default the Q.Menu button brings up a compact-camera-like user interface which has 13 parameters ranged across the top and bottom of the screen. You can either scroll through these options using the front control dial or simply press directly on them if you're using the rear screen. Rotating the rear dial then changes the selected setting.
The 'Preset' Q.Menu offers access to a range of shooting parameters - most of them fairly top-level choices.
Alternatively, an option on page 6 of the Custom menu allows you to switch from this 'Preset' Q.Menu to a customizable version. This alternate version provides access to ten parameters, arranges ten large buttons spread over two screens. The advantage of this system is that pressing the small 'wrench' button at the bottom left of the menu allows you to populate the menu with your most-changed parameters.
The 'Custom' Q.Menu offers up to ten of your most-used settings, including more specialized options such as enabling HDR and histograms.
Pressing the Q/wrench button at the bottom left allows you to drag-and-drop your favoured options from a list of 24.
The Q.Menu always begins with the last option you chose, so you can choose to cluster related settings together, to make access as fast as possible
In a significant upgrade over the GH2, the GH3's viewfinder is an OLED 1.7 million dot equivalent unit. Directly beneath the eyepiece you can see a sensor for automatic switching between the EVF and rear panel display. A diopter adjustment knob juts out slightly from the right edge of the rubber eyepiece cover.
The GH3 features a new viewfinder panel. Panasonic describes it as 1.7m dot equivalent, which suggests it doesn't use a simple three dot-per-pixel relationship. We know it has a resolution of 853x500 pixels, however.
The EVF gives 100% field-of-view coverage but you only fine yourself using the entire display when shooting in the 16:9 ratio. In other aspect ratios, you end using only a crop of the screen.
Panasonic claims 0.67x magnification, making the GH3 one of the larger viewfinders in its class - a touch taller than that in the D7100.
However, we found the viewfinder optics to be disappointing - it's difficult to ever see the whole panel and the corners are fuzzy unless you look straight at them (a problem that gets even worse if you wear glasses). We also found a distinct color cast to the EVF panel, meaning it gave a different (and apparently less accurate) color rendition to the rear screen. No amount of tweaking the fine tune settings in the menu could get the EVF to render greens the way they appear in the final output.
The GH3's pop-up flash is aligned with the center of the lens mount. It has a relatively low guide number of 13m at ISO 200, but does offer 24mm (equiv.) coverage to match Panasonic's recent 12-35mm F2.8 lens. You can of course attach a more-powerful external flash via the camera's hotshoe.
The GH3 is also the first Panasonic to be able to control an offboard flash wirelessly.
The GH3 is among the more button-heavy cameras you'll find in any class, with four sitting along the camera's top plate alone. A deeper handgrip design has allowed for a second control dial just behind the shutter button.
The power switch juts out from the mode dial, and you can see status lights for both power and Wi-Fi connection.
Three of the camera's five customizable Fn buttons are located to the right of the rear OLED. A 4-way control dial with central button sits here as well. Above the 'DISP.' button you can see openings for the GH3's speaker.
A fifth Fn button and playback button sit to the left of the EVF. Above them on the camera's shoulder is a drive mode dial, which replaces the AF mode dial found on the GH2.
The GH3 has a dedicated drive mode dial, as opposed to the switch operation found in the GH2. A flash PC sync port sits below it on the camera's front plate.
A 3.5mm mic socket (versus 2.5mm on the GH2) lies on the camera's left side, eliminating the need for mic owners to use an adapter. You can also see the flash pop-up button located on the viewfinder housing.
The GH3 sports the familiar Panasonic thumb dial. With Panasonic's decision to devote the camera's second function dial to drive versus focus mode, a three-position focus mode lever now surrounds the AF/AE lock button, in a design reminiscent of the company's old Four Thirds SLRs.
The movie record button has been moved from the top plate to the rear of the camera.
The AF assist lamp has been re-positioned - much more sensibly - to the right of the lens mount where you're far less likely to inadvertently block it with your finger.
A hotshoe sits atop the viewfinder housing. On either side of it lie the camera's stereo microphones.
On the left hand side of the camera is a combined USB/video out connector, and a HDMI port that can be used to connect the GH3 to a monitor or external video recorder.
Above them is a second rubber-flapped door concealing a headphone socket for audio monitoring.
The GH3's SD card slot sits behind a sprung plastic door on the handgrip.
The door to the GH3's battery compartment lies underneath the handgrip. The GH3 uses a high capacity 14Wh Li-ion battery pack (Model DMW-BLF19PP)
The camera's tripod socket is aligned with the center of the lens mount, positioned far enough from the handgrip to allow for a battery change when the GH3 is attached to a tripod plate.
The electronic connectors (shown here with cover removed) are for communication the GH3's optional vertical grip.
grip not only allows the use of an additional battery but also duplicates all the GH3's top-panel controls - including its control dials.