Panasonic GX85 Field Test Part II

A whole lot of advanced performance packed into a compact body

By Eamon Hickey | Posted: 09/14/2016

Panasonic GX85 offers fast all-around performance and surprisingly good autofocus

I’ve now shot with the Panasonic GX85 in a wide variety of situations from travel and street shooting to sports, and I’ve had no complaints about its responsiveness at all. It shoots fast; controls respond quickly; shutter lag is minimal; and I’ve never hit any limits on the buffer when shooting bursts. It’s just a speedy shooting machine, as an advanced camera should be.

Olympus M.Zuiko 12mm f/2: 24mm-equivalent, f/4.5, 1/160s, ISO 200, -1EV
The Olympus M.Zuiko 12mm lens came in handy for some street scenes.

For most of my everyday shooting, I use the S-AF autofocus mode, and it has worked great on the Panasonic GX85 -- fast and decisive. Panasonic claims that the GX85’s autofocus is improved in low light, and I don’t doubt this. I’ve used it in very dark situations indoors and at night with almost no focus hunting and only a slight slowdown in AF speed. In all my shooting, I had total confidence in the GX85’s S-AF performance.

To test how well the Panasonic GX85 does with moving subjects -- i.e. in C-AF mode -- I went to East River Park to shoot runners, bicyclists, and Frisbee players. I shot mostly with the Panasonic G X Vario 35-100mm f/2.8 ASPH lens, and I used it wide open at f/2.8 to put the maximum stress on AF accuracy. Although my tests were certainly not exhaustive, I was impressed with how well the GX85 can follow action. I used the Medium burst speed of 6 frames-per-second, which is the fastest setting that still allows live view of the scene. My hit rate was well over 50%, using both the single-area AF patch and the Custom Multi AF area. The camera did better with the predictable motion of bicyclists (all cameras do), but it also did a perfectly credible job with the much less predictable Frisbee players.

Lumix G X Vario 35-100mm f/2.8: 200mm-equivalent, f/2.8, 1/800s, ISO 200
This is part of a 25-image sequence with a better than 90% in-focus hit rate. C-AF with 1-area AF Area Mode.

The significant drawback to action shooting with the GX85 is one that’s shared by all electronic viewing cameras that I’ve tested: the live view that you see in the EVF or LCD is not exactly real-time -- it lags slightly behind the real-life action -- and that makes it tricky to track fast moving subjects and keep them centered in the frame. Compared to other electronic viewing cameras I’ve used, the GX85 isn’t the worst, but it’s not exceptionally good either.

I also did brief separate tests of the Tracking AF-area mode and the Eye/Face Detect modes, and both did a good job of sticking with my intended subject. Eye Detect AF has evolved into a useful technology, and the Panasonic GX85 does it well.

Lumix G X Vario 35-100mm f/2.8: 200mm-equivalent, f/2.8, 1/1000s, ISO 200
In New York, ya' gotta' have style. From a sequence with over 90% in-focus hit rate. C-AF with 1-Area AF Area Mode. (This image has been cropped. Click image for original.)

The GX85 sports 5-axis image stabilization, and it works in both still photo and video recording modes. In my informal tests, it allowed me to pretty consistently get sharp handheld shots at shutter speeds up to about 3 stops slower than I would have been able to manage without it. Although I don’t have a way to quantify the benefit, my impression is that it works very well for video, too -- and I did shoot some telephoto video clips using the 35-100mm lens that would have been impossible without good image stabilization.

Lumix G X Vario 35-100mm f/2.8: 200mm-equivalent, f/5.6, 1/1300s, ISO 200
The G X Vario 35-100mm lens let me reach across the Hudson River for another shot of contrasting transportation modes. (This image has levels tweaked. Click image for original.)

4K Photo, Focus Bracketing, and other interesting tricks

Special features abound on the Panasonic GX85 -- several of them tied to the camera’s 4K video recording capability -- so I spent a fair bit of time exploring a few of them to see if I could learn some new tricks. One is Focus Bracketing, which we described in the Overview section. It was fairly easy to set up, although the step, or focus increment, setting is just a magnitude number (ranging from 1 to 5), so it’s hard to know how much it will actually change the focus between each shot. I guess a GX85 owner would learn how big an effect the increment settings have through trial-and-error. I tried the feature out on a flower shot, and it worked well. The Lumix GX85 fired through the sequence of 7 full-res shots very quickly, and looking at the pictures later, I had a range of useful choices in terms of where the focus was distributed across the flower. I could see myself using this feature for macro work, although I doubt I’d use it for anything else.

In this shot from a 7-shot focus bracket sequence, the focus has been shifted backwards from the originally detected focus plane. More of the flower is sharp in this shot, compared to the unshifted image from the sequence.
Lumix G X Vario 35-100mm f/2.8: 144mm-equivalent, f/2.8, 1/160s, ISO 500
Click above image to see 100% crops from 2 images in a 7-shot focus bracket sequence. In the one labeled "+2" the focus has been shifted rearwards from the originally acquired focus plane (shown in the crop labeled "0"). More of the flower is sharp in the shifted image, but the nearest petal has blurred.

Another special feature on the Panasonic GX85 is 4K Photo, also described in the Overview section. This was my first time experimenting with this feature, and I tried it several times on different kinds of action. My impressions are mixed. At first, I thought it might be useful to shoot sports action, so I tested it on some pickup basketball players. But the camera’s tracking autofocus doesn’t work very well in 4K Photo mode, and I had a lot of out-of-focus frames. So next I went looking for action scenes where the subject isn’t moving all that much in relation to me but where 30 frames-per-second could be useful. I had a few ideas, and tested it on a group of birds (to catch the moment when they all simultaneously take flight), and on some dogs play-fighting (to catch the moment of peak action). Again, spotty AF performance hurt my success rate here, but I think with some more practice and experimentation I could use this feature to get a lot of interesting shots that would be much harder to consistently accomplish with slower frame rates. Almost anything where the location of the action is predictable or not changing rapidly would be a good candidate.

Lumix G X Vario 35-100mm f/2.8: 90mm-equivalent, f/2.8, 1/500s, ISO 800
4K Photo Burst mode gave me about 50 finely delineated facial expressions to choose from here. (But it didn't work well for most of my other basketball sequences.)

I also compared the quality of the Panasonic GX85’s 4K photos to duplicate images shot in normal photo mode, then downsized to the same pixel dimensions. The standard photos are a little sharper and less prone to artifacts, but in most cases the difference is not huge. However, with certain subjects, especially at ISOs above 400, I got some 4K Photo frames with obvious smearing artifacts, which I can’t really explain. Scrolling through 4K Photo clips on the camera’s LCD in order to pick out individual frames to save is a bit tedious, but Panasonic has done the best I could expect with the interface. Scrolling is fast, and you can instantly magnify a frame to check focus or scene details. It’s just that for every second of action you recorded, you have 30 frames to look at.

Post-Focus is another 4K-related special feature on the Panasonic GX85, which, again, we described in the Overview section. It’s a pretty imaginative use of 4K video recording for taking still photos, and it worked perfectly well in my test shots. As an engineering feat, I admire it. But this is one feature that I could not imagine ever using for a real-life practical purpose. At best, it would be only marginally more convenient than taking a couple of extra standard shots with varying focus positions, and those standard shots would be higher resolution, with overall better quality.

Lumix G X Vario 12-32mm f/3.5-5.6: 50mm-equivalent, f/5.2, 1/125s, ISO 800

Firmware v1.1 adds in-camera Focus Stacking!

By Dave Pardue | Posted: 10/19/2016

Using 4K Photo technology similar to that used in their Post Focus feature, Focus Stacking allows you to render as much of an image in focus as you'd like, while leaving the remaining foreground and/or background out of focus. With firmware v1.1 announced in late September, Panasonic has now brought this cool little feature to the Panasonic GX85.

For GX85 owners wanting to try this out, you'll first want to upgrade your firmware of course, and once upgraded go into your menu under the camera icon and select the "Post Focus" option and set it to "ON". Choose a scene to shoot, preferably a still scene while using a tripod. Half-press to focus on your desired focus point and then fire the shutter. You will now see focus points dance through the image, and the clip takes about a second to capture.

It's now created a MP4 file of the sequence, and you're ready to process the image. Note that like Post Focus and 4K Photo, the resulting MP4 file isn't standard 4K dimensions when shooting the GX85 in 4:3 mode -- it's 3328 x 2496 pixels versus 3840 x 2160 pixels for 4K UHD video. This gives a pixel count very similar to a 4K video frame (8.3 megapixels), but in the sensor's native 4:3 aspect ratio.

From the play menu, access the file, which will have "4K" in the icon at the top and will also say "Post Focus Play". Tapping on that icon will take you into the post-focus options. From there, hit Fn3 and you'll be asked whether you want the camera to merge the scene for you (auto) or whether you'd like to choose the "range" to be in focus prior to the merge. For "auto" just press it, wait about a minute for processing, and your image will be ready for you. For range, you'll use the Fn1 button and the arrow keys to set the range using focus points, and then you'll press enter when ready for the camera to work its magic.

Below are three examples from the same still life scene, shot with the Nocticron 42.5mm f/1.2 lens at f/2.8 on a tripod. It's all the same "shot" (or series of 4K frames to be more precise) but processed internally in three different ways.

Auto: You'll note that "auto" did not choose to make the entire scene in sharp focus, leaving the shirt in the far background nicely de-focused. It did, however, choose to keep most of the subject matter nice and sharp.
Medium-wide ("Wide"): For this shot I selected focus points from the first coin in the center to the key near the back. As a result, the 4-shilling note is only partially in focus. It allows most of the items to at least have some detail, while still having some depth overall.
Narrow: For this shot I chose a narrow range just before and after the cicada bug in the center. The result is a nice, narrow range allowing both shells on either side of him to be fully in focus, but yet still allowing for the shallow DOF otherwise provided by the Nocticron at f/2.8 from close range. This is perhaps the coolest use of this feature to me, whereby you can really dial it in precisely to only the subject or subjects you want sharp, and yet fully retaining the otherwise nice bokeh! (Click images to access the full-resolution versions.)

So there's a brief introduction to Focus Stacking with the GX85 via the firmware v1.1 upgrade. Note that you can't achieve true full-resolution images nor capture RAW files (the "raw" file in this case is an MP4, if you will) but you do achieve an amazing amount of control over the focus potential of your final image. And best of all, you can create virtually as many different varieties as you want, from super-shallow to practically everything in focus.

Now back to our regularly scheduled field test...

Sharp lenses; no problem to lug around with the GX85

The Panasonic GX85 body that I tested came with the LUMIX G Vario 12-32mm / F3.5-5.6 ASPH kit lens. I’ve used this lens before, and liked it. It’s extraordinarily small and covers a focal length that I find extremely useful. Check out our review of this lens to get more information on its excellent performance, which is very impressive for such a small and inexpensive optic.

Lumix G X Vario 12-32mm f/3.5-5.6: 64mm-equivalent, f/5.6, 1/80s, ISO 2500

As I mentioned, I also received a Panasonic G X Vario 35-100mm f/2.8 Power OIS lens. We reviewed this lens and gave it extremely high praise for its sharpness and overall optical quality. For me, its compact size and reasonable weight have been a big plus -- it’s exceptionally easy to carry around, yet gives you very useful telephoto capability and decent ability to throw backgrounds out of focus. I did almost all my sports and action photography with it, and it focused very quickly and quietly on the GX85.

I also used the Olympus M.Zuiko 12mm f/2 lens on several of my shoots. Like the lenses I already mentioned, we reviewed the M.Zuiko 12mm extremely favorably, and it remains a favorite of mine, partly because of its innovative clutch mechanism for switching between auto and manual focus. I used it for some street images as well as a handful of architectural shots. It worked perfectly on the Panasonic GX85 with very quick and decisive autofocus and apparently seamless in-body image stabilization. The focus clutch works normally on the GX85, as well.

Underscoring the portability benefits of the Micro Four Thirds system, I often carried the Panasonic GX85 and all three lenses in a single compact fanny pack.

Olympus M.Zuiko 12mm f/2: 24mm-equivalent, f/5.6, 1/500s, ISO 200, +1EV

Gain in-camera raw development, lose the shutter shock

Check out the Image Quality Comparison section of this review for an in-depth look at the Panasonic GX85's image quality and print quality. I’ll just add my overall impression, plus a couple of small notes. My test shots look top-notch -- exactly what I would expect from a good 16-megapixel Micro Four Thirds sensor with no OLPF. I also have the impression that Panasonic’s default JPEG processing has improved compared to the earliest Panasonic cameras I used a few years back -- the color and tonality of out-of-camera JPEGs from the GX85 look nice to my eye, for the most part.

As we noted in the Overview, Panasonic is touting a new shutter design for the GX85 that is meant to reduce or eliminate shutter shock. I did not attempt a controlled test of this, but I shot over 500 images distributed fairly randomly at shutter speeds from 1/30 to 1/200, and only a tiny handful show any kind of unexplained softness. As far as I can tell, shutter shock is not something to worry about with the GX85.

Olympus M.Zuiko 12mm f/2: 24mm-equivalent, f/4.0, 1/60s, ISO 320, +1EV
Converted from raw in camera with several adjustments, including: L-Monochrome; Red Filter; Highlights -4; Contrast +2.

I also made use of the Panasonic GX85’s new in-camera raw development feature to test a few different processing treatments, including the new L-Monochrome Photo Style. I don’t think it’s a make-or-break feature, but I like the ability to develop raw images in camera -- you can experiment with multiple different looks even if you don’t have your computer handy, then upload them to social media via a Wi-Fi connection to your smartphone if you get something you like. Panasonic’s raw development implementation is pretty good, offering a wide range of adjustments and a fairly intuitive interface. Finally, on the handful of images where I tried it, the L-Monochrome Photo Style looks good -- I think I would generally prefer it to the standard Monochrome style.

Lumix G X Vario 12-32mm f/3.5-5.6: 26mm-equivalent, f/5.6, 1/640s, ISO 200

The Panasonic GX85's new Wide Panorama mode also worked well, with the ability to capture up to 360 degrees, though vertical resolution is quite low at only 960 pixels versus 1920 for Standard mode (both modes capture up to 8176 pixels horizontally).

Lumix G X Vario 35-100mm f/2.8: 96mm-equivalent, f/4.5, 1/125s, ISO 2000
(This image has levels tweaked. Click image for original.)

Summing it up

After shooting more than 1,000 images with it, I’d say the Panasonic GX85 definitely does what it sets out to do: pack a whole lot of advanced photo power and performance into a really compact package. I’d feel very comfortable using the GX85 as my main camera, confident that I could tackle 95% of the shooting situations I’d ever encounter. For a critical sports assignment, I’d probably go with a DSLR (due only to the EVF/LCD lag issue), but for everything else I can think of, the Panasonic GX85 is a great performer in a deceptively small package.


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