Panasonic S1 Performance

Very good overall performance with deep buffers, though buffer clearing can be sluggish.

Powering on and taking a shot was reasonably fast for a mirrorless camera, at about 1.5 seconds. Switching from Play to Record mode and taking a shot was quite a bit faster, at about 0.6 second. Good performance here for a mirrorless camera, though most DSLRs are faster at startup.

The Panasonic S1's autofocus speeds were quite good in our tests, especially for a camera that uses contrast-detect AF. In the lab, the S1 produced a full-autofocus shutter lag (with the subject at a fixed distance) of 0.154 second using 1-area (center) AFS mode with the Panasonic Lumix S Pro 50mm f/1.4 lens using default mechanical shutter mode. That's competitive with a lot of pro DSLRs.

Shutter lag in manual focus mode was very low at only 0.067 second, and prefocused shutter lag was lower at 0.060 second. Good performance here.

Using the Electronic Front Curtain Shutter (EFCS) mode produced slightly faster results, while the fully electronic shutter option increased shutter lag slightly. Note that the S1 offers an Auto shutter mode which switches the shutter type to suit the recording conditions and shutter speed, but it defaults to mechanical shutter.

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.

Single-shot cycle times were quite fast at less than 0.4 second for best quality JPEGs or RAW+JPEG files. (Note that we no longer test single-shot mode with just RAW files, as the results are usually somewhere in between.)

In Continuous H mode, the fastest full-res burst mode, the S1 captured best quality JPEG images at about 8.9 frames-per-second and RAW or RAW+JPEG files at 9 fps, almost dead-on Panasonic's spec. Note that autofocus is locked at the first frame of a burst in this mode (AFS). Panasonic claims the S1 can manage up to 6 fps with AF updated between frames (AFC) when using the mechanical shutter or EFCS, and 5 fps using electronic shutter, however we did not test those modes in the lab. In addition, the S1 offers medium (M) and low (L) speed continuous modes, rated at 5 and 2 fps respectively.

The S1 also allows you to capture 6K (18 megapixel) JPEGs at 30 fps or 4K (8 megapixel) JPEGs at 60 fps with no limit other than card space, using the electronic shutter.

Buffer depth was outstanding when shooting best quality JPEGs in Continuous H mode, with no apparent limit using our Lexar Pro 2933x XQD 2.0 card. Buffer depths fell to 124 RAW frames and 74 RAW+JPEG files, though that's excellent and exceeds Panasonic's spec of 90 and 70 frames respectively.

The S1 also has 6K and 4K Photo burst modes, which capture 18-megapixel JPEGs at 30 fps and 8-megapixel JPEGs at 60 or 30 fps respectively with no apparent buffer limit (other than card space or elapsed time).

Full resolution buffer clearing times were on the slow side for XQD when shooting RAW or RAW+JPEG files, though, taking 12.3 seconds after 124 RAW frames and about 18.1 seconds after 74 RAW+JPEG files in Continuous Hi mode. However, clearing after a long burst of best quality JPEGs was quick at just under a second, and the camera lets you make setting changes, review just-shot images and continue shooting while the buffer is clearing.

To see how a fast SD card compared, we re-tested Continuous Hi mode with our Lexar 2000x UHS-II SDXC card, and here are the results:

Interestingly, switching to a fast UHS-II SD card did not impact buffer depths by as much as we had expected. Buffer depth with best quality JPEGs was still unlimited, RAW buffer depth dropped from 124 to 97 and RAW+JPEG buffer actually went up a bit from 74 to 78 frames. Clearing times were longer, though, ranging from 1.3 seconds to 28.2 seconds for full-res images depending on the file type, versus 0.8 to 18.1 seconds.

Bottom line, the Panasonic S1's performance was quite good overall in the lab, with reasonably fast startup, quick autofocus, low shutter lag, fast cycle times, very good burst performance and generous buffer depths. Buffer clearing can be sluggish, though, even with a fast XQD 2.0 card.

Battery Life
Good battery life for its class, with flexible power options.

The Panasonic S1 uses a custom DMW-BLJ31 rechargeable lithium-ion battery pack for power, and comes with a single battery and a dedicated battery charger. In-camera battery charging and power supply via USB are both supported. Battery life is CIPA-rated for between 360 and 380 shots per charge depending on which display is active. That's slightly above average for a mirrorless camera but not nearly as good as most DSLRs when using their optical viewfinders. However the S1 has a Power Save LVF mode which when enabled, increases battery life to an excellent 1,100 shots per charge according to Panasonic. And the optional DMW-BGS1 power grip can double battery life with a second battery.

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))