The Lens

Perhaps the most impressive engineering feat on the LX100 is its lens. Back when the LX7 came out, it was impossible to design a lens compact enough to work with a sensor this large. But lens design has evolved a lot, as you can see below.

On the left is the size and design of the LX7's lens. Next is the LX100. On the far right is how gigantic the lens would be if Panasonic simply upscaled the lens used on the LX7 to cover the larger sensor area. This larger lens would be around half a stop faster, but we think that most people would rather have something a bit more compact.

The lens is designed so that the six groups can move either together or independently, which keeps the size down and allows for focusing as close as 3cm. To ensure relatively circular bokeh the LX100 has a 9-blade aperture and the company promises the lens design and manufacture has had good quality bokeh in mind.

The LX100 uses Panasonic's DFD (that's depth from defocus) system, which reduces focus times to 0.14 sec (with the company's testing methodology, at least). DFD uses two images taken at different focus distances to figure out how far to move the lens, which greatly reduces the 'hunting' that is common on contrast-detect AF systems. We've seen this technology in action on the DMC-FZ1000 and were quite impressed.

And now, here's the payoff of the lens and sensor combination: impressive control over depth-of-field.

You can extrapolate two things from the graph above. First is depth-of-field, or rather, how shallow it can be. The lower the line, the more control you have. As you can see, the LX100 offers a full stop advantage over the Sony RX100 III as you near 50mm, and about a half-stop compared to the Canon G1 X II. The lens isn't quite long enough for traditional portraiture, but for macro work it'll be fantastic.

The second thing you can gather from the chart is how well a camera performs in low light. This isn't as clear cut as depth-of-field, but it's reasonable to assume that a camera that lets in more light will perform better when it gets dark (something affected by both sensor size and aperture). The LX100 is again the leader amongst its peers.

Lens peformance

The LX100's lens is an ambitious one, a 24-75mm equivalent, F1.7-2.8 stabilized zoom that covers a 180mm square sensor area, yet contracts down so that the entire camera ends up being around 5.5cm (2.2in) deep. So, is there a price to be paid for incorporating such extensive capability into such a comparatively small body?

As with the majority of other wide-angle zoom compacts, the LX100 uses digital correction as part of its lens design. Since you automatically get these corrections in JPEG and from any Raw converter that fully supports the camera, we base our assessments of the camera's image quality on images with the corrections applied.

The lower resolution of the LX100, relative to the Sony RX100 III and Canon G7 X make it a little harder to assess the relative sharpness of the Panasonic, but at their 24mm equivalent setting it's clear that the Sony comes out strongest (in the center). It's still visible if you reduce both images to a common resolution.

At the corners, you can see the Panasonic isn't completely removing the lenses' underlying geometric distortion, and is producing pretty solid results. This remains true whether compared at the distance of our test chart or in a real world example. Sadly our comparison tool means you can't compare the far corners of s 4:3 and 3:2 image, so you need to select two 3:2 cameras to see how their extreme corners behave.

Search through the different focal lengths and it's only really 35mm equivalent at the closer focus distance of "our test scene", that looks a little disappointing. In "real world conditions" it looks fine. And again, at "75mm equivalent", wide open in the center, sharpness isn't as good as usual. But "the corners are pretty good", and the center seems pretty good at "real-world distances", so there's still not too much to worry about.

Considering we've only been looking at lens performance with the aperture set wide-open, you can see the LX100's lens is remarkably consistent, both in terms of across-the-frame performance and across its zoom range. "Stopping it down a little bit" improves the performance even at its weakest point (full zoom, at close-ish shooting distances), so overall we'd say it's a very impressive lens and one you don't have to think too hard about, before using.

We'd highly recommend experimenting with different focal lengths, apertures and the two shooting distances, but overall, the LX100 does very commendably.