Autofocus

The Panasonic GX85 features the same 49-point Contrast Detect AF system found in the Panasonic GX8 and makes use of Panasonic’s Depth from Defocus technology (or 'DFD', which only works when shooting with Panasonic glass). DFD works in conjunction with lens profiles that understand how out-of-focus objects are rendered in front of, or behind, the focus plane for any particular lens, helping the camera decide whether to drive the focus element forward or backward to achieve focus. The technology helps the GX85 achieve a 6 fps burst rate with continuous AF.

We ran the GX85 through our subject tracking bike test and found it gave us nearly identical results to the GX8: it can track a moving subject you initiate focus on while firing a burst at 6 fps with a very impressive hit rate. The same can be said for depth tracking a moving subject using just a single point you keep over your subject; the hit rate is very high. While the F11 equiv. depth-of-field certainly masks any small focus errors, this is one of the more impressive contrast-detect AF systems we've seen. And Panasonic's ability to track a subject no matter where it moves to in the frame is impressive.

One odd thing we encountered while testing the GX85's subject tracking mode is an inability to subject track when the picture style is set to any of the B&W modes. This is presumably due to the lack of color information, which the camera normally uses to track your subject.

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The above roll-over was shot at 280mm equiv. The 16 images above were taken from a burst of about 50 and are representative of our overall hit rate.

Face detection is a useful and well-implemented feature. Its functionality on the GX85 is also identical to that of the GX8: when a face is detected, a yellow box appears followed by a green box when focus is confirmed. The camera also has eye detection and will place a cross-hair over eyes it has locked focus on. When there are multiple faces, the GX85 will usually picks the nearest face to the camera. You can also tap the screen on a face of your choice to prioritize it. But if you move an AF point over the face of your choice, it simply turns off face detect, which can be irritating.

The GX85 also offers Face Recognition AF. This features that allows users to 'store' and name the faces of individuals they'd like the camera to recognize. Once a person's face has been saved to the camera, when GX85 recognizes them in a scene, it will prioritize focus on the individual.

The GX85 also has touch AF (and touch-to-shoot). And when one’s eye is to the finder, the touchscreen can be used as an AF trackpad. You can also set the four-way controller on the back to be an AF point selector (in the menu, turn ‘Direct Focus Area’ on).

Performance

Spoiler alert: Pretty much the only thing not awesome about the GX85 is its field sequential EVF.

The GX85 is quick to start up and overall operation is very responsive. This is especially true of the GX85's touch interface. Panasonic's touch implementation is outstanding and has been for a few generations. Touch-to-focus and touch-to-shoot both work near-instantaneously.

However, one major area the GX85 falls flat in terms of performance is its electronic viewfinder. This field-sequential LCD panel is simply put, not very good. Keep in mind, it is the same panel from the GX7, which debuted back in 2013. Three years ago, this EVF may have cut it, but having used cameras like the GX8 and Olympus PEN-F, which use much more modern, higher magnification OLED panels, the GX85's feels dated.

Because colors channels refresh one at a time, panning or zooming with your eye to the finder can result in color tearing. And when using the EVF while the camera is set to continuous AF, the rapid lens hunting combined with color tearing is a recipe for a headache. Adding to the EVF woes, Panasonic gave the panel a 16:9 aspect ratio (presumably to cater to video shooters). But when shooting in the sensor's native aspect ratio of 4:3, the scene viewed through the EVF is quite small. Simply put, I found little to like about the GX85's 2.76M-dot field sequential EVF.

Burst shooting

The GX85 is capable of a 10 fps burst with focus locked using the electronic shutter and 8 fps with focus locked using the mechanical shutter. To achieve these burst rates, set the camera's drive to the 'High' setting and switch the focus mode to AF-S. If you leave the camera in AF-C with the drive set to 'High,' you will only get a 6 fps burst (with no AF points shown).

The fastest burst rate available while using continuous autofocus is 6 fps, with the camera's drive set to 'Medium.' This is also the fastest burst rate in which a live feed is provided and AF points are displayed.  If you shoot at a faster rate, you simply get a playback of images between shots and cannot see where your focus points are.

The GX85 can also fire images at 40 fps using its 'Super High' burst mode, but resolution drops significantly.

Image Stabilization

For stills shooting, we ran the Panasonic GX85 through our standard IS test at 50mm and found that when using Dual I.S. (sensor+lens IS) it gave us the equivalent of 3 stops of additional handhold-ability. That's about one stop behind the Olympus PEN-F, the class leader in terms of stabilization.

You will only enjoy that level of stabilization when using a Panasonic lens with IS, which gives the camera added stability, by working in concert with the GX85's 5-axis sensor-shift IS system. 

The GX85 can also use Dual I.S. during video capture, which we found is very effective for hand-held shooting. Additionally it offers a video E-stabilization option similar to that found in Olympus Four Thirds cameras. Turning it on crops in the frame slightly, but makes the shot that much more steady.

Below we've compared the different video IS modes on the GX85 to video IS offered by other cameras including the GX8 and PEN-F.

It's worth noting that e-stabilization during video capture on the GX85 does crop in the frame slightly.

Battery Life

The GX85 is CIPA-rated to 290 shots per charge. That's about 40 shots less than the GX8, which uses a larger capacity battery. In use, I found battery life to be just barely acceptable. On a full charge, you can probably get through a whole day of shooting stills (or one hour shooting a concert), but if you plan on rolling any video, you'll definitely want to carry an extra battery with you. And because the GX85 does not ship with a charger, the only way to juice up its DMW-BLG10 Li-ion battery is through internal charging.

I realize internal charging is a pretty big deal for Panasonic Four Thirds camera (the GX85 is one of the first to offer it), but there is something about buying a camera, only to be skimped on the charger, that bugs me. Of course you could always pick up a charger for about $30 (assuming you can find one in stock somewhere).