Although it's a couple of years now since Sony launched its original RX100 (RX100 vs. RX100 III; RX100 vs. G7X) the large-sensor compact zoom camera is still a pretty new breed of camera. Doubly so when you consider that until very recently, Sony has had the segment almost to itself. It's quite interesting -- and a sign of the category's nascence -- just how much the early entries in this market differ, all the way from the extremely compact RX100 to the chunky G1X (RX100 III vs. G1X; LX100 vs. G1X).
The two cameras we'll be looking at here, the Sony RX100 III and Panasonic LX100, fall somewhere in between these two extremes. The RX100 III is slightly larger and more feature-rich than the original RX100, the camera that defined the category. Panasonic's rebuttal is the LX100, a camera that's about halfway between the size of the RX100-series and Canon's G1X series, and looks to have quite a strong feature set that does much to woo enthusiast photographers.
But how do these two cameras differ, and which is right for you? Read on, and find out!
The most obvious differences between the Panasonic LX100 and Sony RX100 III come down to size, first and foremost. Although these cameras are both classed as large-sensor, enthusiast compacts with zoom lenses, and size has clearly been a key factor in the design of both, each company took a very different approach in the design of its product.
With the RX100 III, Sony focused its attentions on camera body size first and foremost, ensuring a design that will fit in a pants pocket (although a larger pocket, at that). At 4.0 x 2.3 x 1.6 inches (102 x 58 x 41 mm), the Sony RX100 III's body isn't radically smaller than that of the Panasonic LX100 in any given dimension. Its rival is only about 0.3 to 0.5 inches larger on each axis, after all, measuring in at 4.5 x 2.6 x 2.2 inches (115 x 66 x 55 mm). Consider the overall volume, though, and the LX100 feels quite a bit bulkier.
Simplifying matters and considering each to be a simple three-dimensional box, the RX100 III is around 40% smaller. And it's noticeably lighter, as well. The LX100 weighs 13.9 ounces (393 g), while the RX100 III tips the scales at just 10.2 ounces (290 g), some 26% lighter than its rival.
But while you won't shoehorn the LX100 into a pants pocket, it will still fit happily in a jacket pocket -- it's not a large camera by any measure. It's just not quite as small as is the RX100 III. And for the extra bulk and heft of the Panasonic LX100, you'll get a significant advantage in terms of sensor area.
That will give it an advantage in terms of how much light it can capture. (Or in its sensitivity, in other words.) The LX100's sensor is a 4/3"-type with a diagonal of around 21.6 mm, and a surface area of about 225 mm2. That's very close to double the 116 mm2 of the RX100 III's 1"-type sensor, which has a diagonal of about 116 mm.
However, Panasonic's sensor extends beyond the image circle in the corners. This allows the company to offer a choice of aspect ratios without simply cropping and discarding image data, but it also means that no available capture resolution can use the whole sensor area, since the corners would be shaded.
The result is that while the LX100 will certainly use more sensor area than the RX100 III, it won't have the same advantage you'd expect of a typical camera with 4/3"-type sensor.
And the difference in surface area is also offset somewhat by the fact that the Sony RX100 III's imager uses a backside-illuminated design. (In a nutshell, that means most of its circuitry is on the opposite side of the chip to the light-sensitive surface, and so the area available to gather light is maximized.)
Panasonic hasn't stated what technology is used in its own chip, describing it only as a "High-Sensitivity MOS" type, but were it a backside-illuminated chip the company would likely have said so. Still, there's only so much you can do with BSI technology. At larger pixel sizes, its advantage becomes progressively smaller and harder to notice.
Odds are that after considering all of the above, the Panasonic LX100 will have the edge in terms of base sensitivity. And while we've yet to complete testing of the LX100 -- we'll update this comparison once we do so -- the manufacturer-rated ISO sensitivity range of the two cameras tells the story.
While the RX100 III has a default range of ISO 125 to 12,800 equivalents, expandable to ISO 80 on the bottom end and 25,600 at the high end (though only in the multi-shot noise reduction mode), the LX100 has a *default* range of ISO 200 to 25,600 equivalents, expandable to ISO 100. Given the similar maximum aperture of the two cameras, that will give the Panasonic LX100 an advantage as an available-light shooter.
The Sony RX100 III, meanwhile, will have an edge shooting in bright sunlight where LX100 users will be forced to stop down sooner. Doubly so because the RX100 III includes a built-in three-stop neutral density filter, which feature the LX100 lacks.
And the Sony also offers higher sensor resolution, which could be important if you need to make large prints or want to crop significantly. With an effective resolution of 20.2 megapixels in 3:2 aspect, the RX100 III offers about 28% higher linear resolution than does the 12.8-megapixel LX100, on paper at least. (Again, we'll need to get the Panasonic through our in-depth lab testing to confirm the real-world difference between the two cameras in this area.)
Despite the difference in body and sensor size, the built-in optics of the Panasonic LX100 and Sony RX100 III are actually pretty similar, on paper at least. Both cameras' lenses carry premium branding, have around a 3x optical zoom range with similarly bright apertures across that range.
In terms of maximum aperture and zoom range, the cameras are evenly matched. Both lenses start from a 24mm-equivalent wide-angle, although at this point the LX100's f/1.7 maximum aperture is just a touch brighter than the f/1.8 of the RX100 III. At telephoto, both cameras' maximum aperture falls to a still-bright f/2.8, but the LX100's 75mm telephoto is a touch longer than the RX100 III's 70mm tele (in 35mm equivalent terms).
The LX100's claimed autofocus time is 0.14 seconds. That's similar to the 0.15 second we measured for the RX100 III, but a final verdict will have to wait till we get the LX100 into our labs. One worthwhile note is that Panasonic provides 49 AF points for the LX100, versus just 25 points in the RX100 III.
On a first look, the cameras appear quite similar in the optical department, but these figures say nothing of real-world sharpness, distortion, vignetting and aberrations. It's pretty common for cameras in this class to make radical corrections to their images to account for the compromises inherent in making such compact, bright zooms for comparatively large sensors. Watch this space for the rest of the story!
While both the LX100 and RX100 III have a surprising number of external controls given their relatively trim, compact bodies, the Panasonic LX100 is the more generously-equipped of the pair when it comes to physical controls. In fact, it just feels more like a camera that was made with experienced photographers in mind, whereas the Sony RX100 III clearly caters to consumers.
Glance at the Sony and you'll see a friendly Mode dial, one of only three dial/ring-type controls on the RX100 III's body. By contrast, the Panasonic LX100 has five dials and rings, and forgoes a Mode dial altogether. Instead, you get dedicated controls for the main exposure variables -- shutter speed, aperture, and exposure compensation. A second lens ring behind that used to control aperture can be configured to control lens zoom, ISO sensitivity and manual focus, among other options.
And while the Sony has but one customizable function button -- used to call up seven different functions which you then adjust by rotating the lens ring -- the Panasonic LX100 has three configurable function buttons.
And the difference in these two cameras' nature is more than skin deep, as well. If you're a less experienced photographer, you'll appreciate the Sony RX100 III's array of 13 scene modes that help you get the results you want without the need to understand much in the way of camera setup (though you will have to divine the difference between Intelligent Auto and Intelligent Auto+ modes). The Panasonic, though, forgoes such niceties altogether: Its only concession to approachability is an Intelligent Auto mode accessed with a dedicated button on the top deck.
One area in which there looks likely to be a clear winner is in the performance department. While our final verdict will have to wait until we've completed our own independent testing, the Panasonic LX100 looks poised to beat Sony's well-entrenched rival in the performance department, on paper at least.
Based on manufacturer ratings, the LX100 beats the RX100 III in terms of burst performance, whether or not autofocus is enabled. (And the difference when AF is active is significant: Panasonic rates its camera for 6.5 frames per second, more than double the 2.9 fps rating provided by Sony.) And the Panasonic LX100 can edge out its rival even without autofocus, too, shooting 11 frames per second, one more than the RX100 III. If you're willing to live with the downsides of a fully-electronic shutter, the LX100's performance rockets to 40 frames per second, but resolution is slashed to just three megapixels.
Add in a faster top shutter speed of 1/4,000 second (versus 1/2,000 second for the Sony), plus the ability to capture 4K video (where the RX100 III is limited to Full HD), and it looks to be a pretty clean sweep for Panasonic on the performance front. (We'll come back to video in a moment for a closer look, though.)
With the exception of shutter speed, the Sony RX100 III and Panasonic LX100 offer quite similar exposure options, but each takes distinctly different approaches to flash that match their focus on enthusiast or consumer photographers. It's hard to call either option better than the other -- this is one that's very much down to personal preference and shooting style.
On the plus side, the Panasonic LX100 includes a flash hot shoe that allows use of your choice of external strobes. That means potentially far more flash range than a camera with a built-in strobe. However, while the Sony RX100 III lacks a hot shoe, it includes a built-in, popup flash strobe. The LX100, by contrast, has to rely on a small external flash strobe that's included in the product bundle, or your choice of separately-purchased flash.
The good news, though, is that the LX100's flash is quite a bit more powerful than that built into the RX100 III. Panasonic rates the bundled DMW-FL70 strobe as having a guide number of 7 meters at ISO 100. Sony doesn't state a guide number, but working backwards from the claimed 30-meter wide-angle flash range at ISO 12,800 suggests a guide number of about 4.8 meters.
So you'll have to remember to bring the strobe with you, but it will easily slip in a pants pocket and will give you more range than that of the RX100 III, so long as you do remember to bring it along.
If you're gunning for a spontaneous shot and want to capture it through the viewfinder, the Panasonic LX100 has a distinct edge over the RX100 III -- its electronic viewfinder is right there, always available so long as the camera is switched on. That makes it quicker to access than the pop-up, pull-out viewfinder of the Sony, even if the latter switches on the camera automatically at the same time the viewfinder is raised.
It's also easier on the eye, thanks to a higher resolution of 1,280 x 720 pixels, compared to the 800 x 600 pixel resolution of the Sony, and has higher 0.7x magnification as well, where the RX100 III is limited to 0.59x magnification.
That's offset somewhat by the LX100 viewfinder's wide 16:9 aspect ratio. With the more typical 3:2 aspect ratio you'll likely use for much of your still image shooting, the black bars at left and right of the LX100's display will greatly reduce the size of the viewfinder image, and even more so for 4:3-aspect shooting. By contrast, the RX100 III's 4:3-aspect viewfinder is better-suited to the most common still image aspect ratios, and so you'll lose less to black bars.
Even were that not the case, though, we'd probably have to give this one to the Sony RX100 III for the much greater versatility of its LCD monitor. For one thing, while pixel resolution is identical to that of the LX100, the RX100 III's display has an extra white subpixel for every RGB triplet of the LX100's screen. That means a brighter, easier-to-see display outdoors, and lower power consumption indoors. The RX100 III's display also tilts upwards 180 degrees for selfie or low-to-the-hip shooting, or downwards 45 degrees for shooting above your head. The LX100's screen, though, is fixed in place -- and that will make framing from unusual angles a rather less satisfying spray-and-pray experience.
Panasonic has a big win in the video-capture arena, with support for shooting at 4K resolution with a rate of up to 30 frames per second. You may not have a 4K display yet, but there's a big push in the industry for you to upgrade, and there's a good chance that at some point in the future you'll do so. If that happens -- or if you just want to crop and stabilize video in software post-capture, 4K could be a big deal for you, and the Sony RX100 III doesn't offer it.
However, Panasonic once again doesn't have an outright victory here. For one thing, we don't yet know whether it captures video using the entire sensor area, or uses striped readout as many cameras do to reduce the load (and generally manufacturers are quick to publicize features that flatter their products). Its rival, the RX100 III, has full-sensor readout that translates to better-than-average video image quality. Sony also offers a higher framerate of up to 120 fps for Full HD (1,920 x 1,080 pixel; 1080p) video, where the Panasonic LX100 is limited to 60p capture. And Sony also offers the ability to shoot 17-megapixel, 16:9-aspect still images during video capture, where stills extracted from the LX100's 4K video have a maximum resolution of 8.3 megapixels.
Both the Sony RX100 III and Panasonic LX100 have good battery life by compact camera standards, if you shoot using the LCD monitor. With that said, to CIPA testing standards you'll get an extra 20 shots out of the Sony, with the Panasonic expiring after some 300 frames with 50% flash usage.
However, switch to the electronic viewfinder and there's a clear advantage for the Panasonic. Here, it will last 270 shots, a full 40 frames more than RX100 III shooters can expect.
And there's another advantage for the LX100, as well: We believe the retail package will include an external battery charger, which means you can be shooting with one pack while recharging another. Sony, by contrast, relies on USB charging in-camera, and that means you'll need to buy a separate charger if you don't want downtime while recharging.
Both cameras have fairly generous connectivity options, including 802.11b/g/n Wi-Fi wireless networking with NFC setup. The latter is still Android-only, though, as despite the fact that Apple's latest phones now include NFC hardware, the company hasn't opened it up to third-party use. (That's Apple's fault, though; there's nothing Sony or Panasonic can do about it.) Both cameras also include USB 2.0 High Speed data connectivity and Type-D MicroHDMI high-def video output.
There is one slight advantage for the Panasonic, though: While the RX100 III lacks any standard-definition video output, Panasonic still includes a composite output which shares the same jack as the camera's USB data connection. It's NTSC-only on US-market cameras, and chances are most photographers will never need it at this point, but it's nice to know it's there, nevertheless.
As of this writing, the Sony RX100 III has a distinct advantage over its new rival. It's already on sale, and priced at just US$800 -- admittedly fairly pricey for a fixed-lens compact camera, but not unreasonable for its category. By contrast, Panasonic has not yet officially stated pricing in the US market, but the LX100 is expected to ship in late October.
However, retailers here are already listing the Panasonic at US$900, a premium of US$100 over the cost of the Sony. Assuming that price holds true, that gives the RX100 III an 11% advantage over the new challenger. It's not a night-and-day difference, but it's enough to put a couple of extra accessories in your camera bag -- or perhaps to buy the camera bag itself. And you can buy it today, as well, where it may be a little while until the Panasonic LX100 is readily available at retail.
And that about wraps things up for this comparison. To recap -- and bearing in mind that we've not yet completed our Panasonic LX100 testing, so we'll likely have more to say soon -- we'd say that the LX100 is the camera to go for if you're a frequent available-light shooter, mainly shoot through the electronic viewfinder, want external flash or more manual controls, or have / plan to buy a 4K display on which to view ultra high-def movies. If pocketability, high resolution for larger print sizes, an approachable consumer-friendly design, or the almighty dollar are more important, then the Sony RX100 III is the camera for you.
And if you haven't made your mind up yet, then it's going to be a tough call to select between these cameras, because they're otherwise pretty closely-matched. Our real-world and lab testing will likely turn up some more advantages and disadvantages for each, though, so watch this space!
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This comparison review, along with the in-progress Panasonic LX100 review and Sony RX100 III review represent hundreds of hours of testing, discussion, writing and editing. So please, support this content by purchasing the LX100 or RX100 III (or any other products) through one of the links below.
Maximum effective ISO is an estimate of the highest sensitivity at which a camera can capture excellent quality photos.
Cameras with higher effective ISO will be better choices for indoor photography, night shooting, and indoor sports photography, especially if you intend to make large prints.
You can learn more at our glossary entry.
Maximum effective ISO test data courtesy of DxO Mark.LX100 test data on DxO Mark RX100 III test data on DxO Mark
Pocket-friendly design; Popup electronic viewfinder; Bright lens across the zoom range; Great performance with very fast autofocus; Very high resolution gives lots of detail in good light; High ISO noise levels much better than most pocket camera rivals; Wi-Fi wireless networking
Feels a little unbalanced without an accessory grip; Not as much telephoto reach as its siblings; Noise processing is heavier-handed than in earlier models; Quite pricey for a fixed-lens camera
Very good image quality; Great performance in most respects; Bright zoom lens with good macro performance; Photographer-friendly body easily fits in a coat pocket or small bag; Roomy, high-res built-in viewfinder; Decent battery life
Won't fit in a pants pocket; Relatively low resolution by modern standards; Zoom lens has only a modest telephoto; Soft corners at wide or tele positions; Aperture dial is too easily bumped; Bundled flash is fairly weak