Lens Performance

Below we'll take a look at how the G5 X's lens compares with that of the Sony Cyber-shot DSC-RX100 III and IV at various focal lengths and apertures.

Starting with the lenses wide open (F1.8) at their wide-angle (24mm equiv.) position you'll see that the RX100 III is considerably sharper than the G5 X near the center of the frame. A glance at the RX100 IV shows that, despite sharing the same lens as the RX100 III, differences in quality due to sample variation can be significant. None of the three cameras are fabulous in the corners, but the G5 X is still blurrier than the two Sonys. Stopping the lens down to F4 improves things slightly, though the Sonys are still a bit sharper. This advantage is maintained in the center at F4.

Jumping back to the center of the frame at 35mm, with the lens wide open (F2.8), we find that story haven't changed much. As before, stopping the lens down (to F5.6 in this case) helps a bit, but not dramatically so. In the corners at 35mm the G5 X remains soft, with a a very small improvement when stopped down to F5.6.

At 50mm we turn our cameras toward Queen Anne Hill. At this focal length the G5 X's lens starts to hit its stride, with sharpness that approaches the quality of the RX100 III. In the center of the frame the Sony remains the leader at F2.8, with the G5 X closing the gap at F5.6. In the corners the G5 X is at its best at F5.6, though still a bit behind the RX100 III.

Since the RX100 twins' focal length ends at 70mm equivalent our direct comparison has come to an end. While we don't have samples taken with the G5 X at that focal length, comparing them at 85mm is still a useful data point. With their respective lenses at F2.8 the Canon fares quite well in the center at the frame. Changing the aperture to F5.6 produces a marked improvement in sharpness, keeping the G5 X ahead of both Sony models. Looking at the corners, the G5 X is quite soft and behind the RX100 III at F2.8, but considerably better at F5.6, catching up to the RX100 III, and exceeding our RX100 IV.

At full telephoto (100mm equiv.) the G5 X is sharpest at around F5.6 both in the center of the frame as well as in the corners, though at this point, diffraction is likely to have set in and will limit image sharpness.

Key Takeaways

If there's one thing that's apparent from of our lens studies of 1"-type 20MP compacts, it's that performance can vary significantly from copy to copy. At these pixel pitches and resolutions, resolving ability of lenses really comes into play, with any small imperfections or misalignments causing often quite visible issues. 

Back when we compared the G7 X to the RX100 III, we found the former, which shares the same lens as the G5 X, to suffer on the wide end relative to the very sharp RX100 III lens. The same holds true for the G5 X, though it appears to perform better than the two copies of the G7 X we tested. Our RX100 IV, an example of a not-so-good copy, suffers so much relative to our RX100 III that our G5 X often meets or outperforms it. 

On the telephoto end, the G5 X's lens performs respectably, sometimes even exceeding the performance of our RX100 III. Based on our testing (and we found three RX100 III copies to be fairly similar), we can confidently say that the G5 X's lens will tend to be softer than a RX100 III lens at shorter focal lengths (24-50mm), but will at least match, if not exceed, telephoto performance, especially considering the greater reach possible. Your results may vary based on your copy, though.