Panasonic GX7 Performance

Generally very good to excellent speed for a Compact System Camera.

Startup time was faster-than average at 0.9 second with firmware v1.1 (with older firmware, it varied from about one to as much as three seconds). Shutdown was a bit slow, though, at 2.1 seconds. Buffer clearing times were good with a fast UHS-1 card.

Mode switching was fast.

The Panasonic GX7's autofocus was very fast, especially for a camera that uses contrast detection. The GX7 produced full-autofocus shutter lag (with the subject at a fixed distance) of 0.192 second using 1-area (center) AF with the 14-42mm kit lens, which is faster than the GX1's 0.259s, and faster than most consumer DSLRs as well. 23-area AF was very slightly slower at 0.232 second, but that's still fast. Enabling the flash increased lag to 0.310 second, but that's still pretty fast. Shutter lag was 0.194 second in continuous mode AF. When manually focused, the GX7's lag time dropped to 0.096 second. The GX7's prefocused shutter lag time of 0.081 second which while quick, is a bit slower than average. Interestingly, enabling the Electronic Shutter increased prefocused shutter lag to 0.11 second.

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 very good, and a bit faster than the GX1. We measured 0.47 second for large/fine JPEGs, 0.48 second for RAW and 0.56 second for RAW+L/F JPEGs.

Continuous High Speed "H" mode was slower-than-average these days, but faster than the GX1's, at about 5.6 frames per second for JPEGs, and about 5 fps for RAW or RAW+JPEG files, compared to the GX1's 4.1 frames per second. Please note that Live View is not available during a burst in H mode.

With the electronic shutter option enabled, though, burst rate increased to 10.7 fps for L/F JPEGs, 8 fps for RAW and 8.1 fps for RAW+JPEG files, which is excellent. In Super HS mode which also uses electronic shutter, we managed 40 frames-per-second, though resolution is only 4 megapixels in that mode. Panasonic warns that using the electronic shutter can lead to distortion in moving subjects and other side-effects, though, so keep that in mind.

Full resolution buffer depths were generous for large/fine JPEGs, at over 20 frames, but when shooting RAW files buffer size dropped to 10 frames, and 9 for RAW+L/F JPEGs. This is on the shallow side for an enthusiast model, but about the same as the GX1's. Buffer depth dropped slightly with the Electronic Shutter mode's faster burst speeds, to 9 RAW and 8 RAW+JPEG, though when shooting just JPEGs, the camera did not slow down after 20 frames. Buffer depth in Super HS mode was a very generous 80 frames.

Buffer clearing was fairly quick for full-res images, ranging from 3 to 9 seconds depending on the file type and mode, though clearing after 80 4MP frames took a leisurely 19 seconds.

The flash recycled after a full discharge in 4 seconds, which is a bit slower than average for its class.

Download speeds were fast, quick enough that you probably won't feel the need for a separate card reader, even with large memory cards. (Note that this test was performed with a SanDisk Extreme Pro 95MB/sec UHS-I SDHC card: Slower cards would likely show slower transfer times.)

Bottom line, the Panasonic GX7's performance is very good overall for a CSC. Startup is fast (with firmware v1.1), mode switching is fast, and autofocus is fast. Full resolution burst speed with the mechanical shutter is mediocre, but very fast with the electronic shutter enabled. Buffer depths are excellent with JPEGs, though somewhat shallow with RAW files.

Average battery life for a Compact System Camera.

The Panasonic GX7 uses a custom rechargeable lithium-ion battery pack for power, and comes with both a single battery and charger. The CIPA rated 320-350 shots per charge depending on the lens is about average for a Compact System Camera, but much lower than a typical digital SLR when using the SLR's optical viewfinder. We strongly recommend getting a second battery for your GX7 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))