Panasonic GX85 Performance


Timing and Performance

Generally good performance for a mirrorless ILC.

Startup/Play to Record

Power on
to first shot

~0.9 second

Time it takes to turn on and capture a shot.

Play to Record,
first shot

~0.6 second

Time until first shot is captured.

Startup time was a little faster-than-average for a mirrorless camera, and switching from Play to Record and taking a shot was fairly quick.


Shutter Response (Lag Time)

Full Autofocus,
Single-area AF mode

0.192 second

Time from fully pressing shutter button to image capture, with the lens already at the proper focal distance setting.

Full Autofocus
Single-area AF mode
Flash enabled

0.423 second

Time from fully pressing shutter button to image capture. Auto Flash enabled.

Manual Focus

0.065 second

For most cameras, shutter lag is less in manual focus than autofocus, but usually not as fast as when the camera is "prefocused".

Prefocused

0.064 second

Time to capture, after half-pressing and holding shutter button.

The Panasonic GX85's autofocus speed was very good our tests, especially for a camera that uses contrast-detect AF only. The GX85 produced full-autofocus shutter lag (with the subject at a fixed distance) of 0.192 second using 1-area (center) AF. That's quite good for a mirrorless camera and competitive with most prosumer DSLRs. Enabling the flash increased lag to 0.423 second to account for pre-flash metering, though that's still pretty fast.

When manually focused, the GX85's lag time dropped to 0.065 second, also very good. The GX85's prefocused shutter lag time was 0.064 second, which is pretty fast.

To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance.


Cycle Time (shot to shot)

Single Shot mode
Large/Fine JPEG

0.44 second

Time per shot, averaged over a few frames (we no longer test for buffer depths in single-shot mode).

Single Shot mode
RAW + L/F JPEG

0.43 second

Time per shot, averaged over a few frames (we no longer test for buffer depths in single-shot mode).

Early shutter
penalty?

Yes

Some cameras refuse to snap another shot if you release and press the shutter too quickly in Single Shot mode, making "No" the preferred answer.

Continuous H
Large Fine JPEG

0.12 second
(8.40 fps);
Unlimited frames(?);
9 seconds to clear*

Time per shot, with no apparent limit (>200 frames).

Continuous H
RAW

0.15 second
(6.71 fps);
53 frames total;
21 seconds to clear*

Time per shot, averaged over buffer length of 53 frames, then slows to an average of 0.63s or 1.60 fps.

Continuous H
RAW + L/F JPEG

0.15 seconds
(6.72 fps);
44 frames total;
38 seconds to clear*

Time per shot, averaged over buffer length of 44 frames, then slows to an average of about 0.79s or 1.27 fps with a lot of variation.

Continuous H
Electronic Shutter
Large Fine JPEG

0.09 second
(10.53 fps);
Unlimited frames(?);
13 seconds to clear*

Time per shot, with no apparent limit (>200 frames).

Continuous H
Electronic Shutter RAW

0.09 second
(10.59 fps);
44 frames total;
21 seconds to clear*

Time per shot, averaged over buffer length of 44 frames, then slows to an average of 0.51s or 1.97 fps with a lot of variation.

Continuous H
Electronic Shutter
RAW + L/F JPEG

0.09 second
(10.60 fps);
40 frames total;
38 seconds to clear*

Time per shot, averaged over buffer length of 40 frames, then slows to an average of about 0.58s or 1.74 fps with a lot of variation.

Super HS mode
4-megapixel JPEG

0.03 second
(40.0 fps);
120 frames total;
11 seconds to clear*

Time per shot, averaged over max buffer size of 120 shots.

Flash Recycling

2.0 seconds

No built-in or bundled flash.

*Note: Buffer clearing times measured with a SanDisk Extreme Pro 95MB/sec UHS-I SDHC card. Slower cards will produce correspondingly slower clearing times. Slow cards may also limit length of bursts in continuous mode. ISO sensitivity and noise reduction settings can also affect cycle times and burst mode performance.

Single-shot cycle times were just over 0.4 seconds for JPEG or RAW+JPEG, which is pretty good. (Note that we no longer test single-shot mode with just RAW files, as the results are usually somewhere in between JPEG and RAW+JPEG.)

Continuous High Speed "H" mode burst speed with the mechanical shutter was quite good for its class, measured at 8.4 frames per second for best quality JPEGs, exceeding Panasonic's 8 fps spec. When shooting RAW or RAW+JPEG files, the frame rate did drop to 6.7 fps, but that's still not bad. Note that these burst rates are with single-shot AF mode (AFS). Panasonic claims up to 6 fps with continuous autofocus (AFC). The GX85 also offers Middle Speed (rated at about 6 fps) and Low Speed (rated at 2 fps) modes, however we did not test those modes in the lab.

The GX85 has an all-electronic shutter mode which the company says boosts the full-resolution frame rate to 10 fps with AFS, and in the lab the GX85 managed just over that, between 10.5 and 10.6 frames per second depending on the file type. Interestingly, there was no drop in speed when shooting RAW or RAW+JPEG like we saw with the mechanical shutter.

A Super High Speed mode which uses the all-electronic shutter is also available which captures Small JPEGs (4 megapixels at 4:3) at 40 frames per second for up to 120 frames.

We did however notice burst performance was very sensitive to aperture used, more so than most cameras we've tested. Even stopping down slightly would reduce burst speed, sometimes significantly. (The above burst tests were performed with the kit lens at max aperture.)

Full-resolution buffer depth was essentially limited only by card capacity when shooting Large/Fine JPEGs (we tested just past 200 frames with no signs of slowing). When shooting RAW files buffer depth was 53 frames, and 44 frames when shooting RAW+JPEG files, which is quite generous. Buffer depths dropped slightly to 44 and 40 frames respectively with the faster electronic shutter mode.

Buffer clearing was reasonably fast when shooting best quality JPEGs with a fast 95MB/s UHS-I card, at between 9 and 13 seconds depending on the mode, but clearing times were quite long when shooting RAW files, ranging from 21 seconds after a burst of RAW frames to 38 seconds after a burst of RAW+JPEG frames. You can however take additional photos and adjust settings while the buffer is clearing.


Bottom line, the Panasonic GX85's performance is very good for its class. Startup and mode switching are reasonably fast, while autofocus speed and shutter lag are very good. Burst performance is very good, buffer depths are excellent, however buffer clearing is slow when shooting RAW or RAW+JPEG files.

Battery Life

Below average battery life.

Operating Mode Battery Life
Still Capture, CIPA standard
(Monitor with H-FS12032 kit lens)
290 shots
Still Capture, CIPA standard
(EVF with H-FS12032 kit lens)
270 shots

The Panasonic GX85 uses a custom rechargeable lithium-ion battery pack for power, and comes with a single battery, a USB/AC Adapter, and USB cable for in-camera charging. The CIPA-rated 290 shots per charge when using the monitor and 270 shots with the EVF are below average for a mirrorless ILC, and much lower than a typical DSLR when using an optical viewfinder. We strongly recommend getting a second battery for your GX85 if you plan any extended outings.

The table above shows the number of shots the camera is capable of (on a fully-charged rechargeable battery), based on CIPA battery-life and/or manufacturer standard test conditions.

(Interested readers can find an English translation of the CIPA DC-002 standards document here. (180K PDF document))

 



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