Sony RX100 III Field Test Part III
Sony RX100 III Field Test Part III
Answering your questions (and mine, too!)
By Mike Tomkins | Posted: 07/22/2014
And so, I've reached the end of my Sony RX100 III Field Test, with the third and final section. For my last report, I wanted to answer some of the reader questions I've received, and to take a look at a few features I'd not yet had the chance to try. Topics for discussion include a look at image stabilization (and how it compares to that of earlier models), some flash testing, and a quick walkthrough of the newly-added PlayMemories Camera Apps. Last of all, I take a look at video capture, an area that has seen some important improvements.
Image stabilization comparison
I'll start with image stabilization, since that's probably the most important feature of the group. I received reader requests to compare the Sony RX100 III's stabilization capability to that of the earlier RX100 and RX100 II, which have apparently drawn some criticism from users since those cameras' launch. (Personally, I haven't found stabilization particularly troublesome on the earlier models, but I think I have a fairly steady hand, which may have helped to bolster my impression.)
I decided to do a reasonably scientific test, or at least as much so as is possible with something so subjective, and without access to a dedicated testing rig. I shot photos of the exact same scene from the same distance with all three cameras, prefocused and using shutter priority and auto ISO sensitivity, and gradually reducing the shutter speed. Exposure wasn't locked, but that wasn't really important given that the shutter speed didn't vary from shot to shot.
All three cameras were fixed to a 50mm-equivalent focal length, shooting a bouquet of flowers from a distance of around 1.5 feet under moderate indoor lighting. Focus was set a bit back from the front of the flowers so that if I didn't get exactly the same distance for each shot, some part of them would still be in focus.
For my stabilization test, I placed a bouquet of cut flowers in a moderately well-lit room, then shot them with the RX100, RX100 II and RX100 III at all shutter speeds from 1/60 to one second, with fixed focus and focal length. The test showed Sony has improved SteadyShot performance in the RX100 III.
Since the flowers were on a table top, I sat down so that I wouldn't have to bend over. To be realistic, I didn't brace the camera or my arms against my body, the table, or anything else. Instead, I shot with my arms outstretched a little. (That might be a bit unfair to the RX100 III, as I could probably have gotten slightly better results with its popup viewfinder, holding the camera to my eye. The same would be true for the RX100 II, though, if using its optional accessory viewfinder.)
I should also note that I'm aware that as much as this was a test of the camera, it was also testing my skills in shooting steadily. (In fact, once I started to get blurred shots at the slower shutter speeds, I usually knew whether a particular shot would be blurred even before I saw the review image on the LCD monitor, just because I could sense my hands moving.) I tried to account for that, though, shooting each camera for five exposures at each shutter speed. I also stepped through the cameras at each shutter speed, so that I wouldn't be significantly more tired when shooting with one model than its rivals come the end of the test. (And for good reason: With a total of 270 shots captured between the three cameras, I'm sure my ability to remain steady was flagging towards the end of the test.)
The exposures started from 1/60 second so I could be sure of a sharp shot, and I tried every shutter speed all the way down to an unrealistically-slow full second. I then made a spreadsheet, assigned a point score from one to three for each shot -- one being perfect, two being at least reasonably near-sharp when viewed 1:1, and three being significantly blurred -- , and averaged to get a score for each shutter speed. I should note here that even quite a few of the shots I called significantly blurred would've been fine or at least usable at smaller print sizes. If a shot showed noticeable doubling rather than just softness when viewed 1:1, though, I gave it a three.
At 1/13 second, 1:1 detail crops from the Sony RX100 III (top left) were predominantly sharp and near-indistinguishable from those at faster shutter speeds. The RX100 II image (top right) shows results more typical from the earlier cameras at the same shutter speed. (This is a result I called as slightly soft, although it'd still be perfectly usable for moderate print sizes.)
Beneath is an image from the RX100 III at 1/60th second for comparison. Note that since the test was of necessity handheld, framing varies a little, as do the point of focus and exposure level. I've cropped with the sharpest area in each image visible, and although brightness varies, all cameras used the same focal length and shutter speed, with similar apertures.
And the results: With the RX100 III, anything down to 1/30 second was perfect. With its predecessors, I started to get the first soft shots at 1/40 second, just a little sooner than the newer camera.
Continuing on down to 1/13 second with the RX100 III, I still managed sharp shots most of the time. Other than a sole outlier at 1/25 second, no shot was significantly blurred, but some of them were a bit soft. With the RX100 and RX100 II, I didn't get as many sharp shots at 1/30th or below, and by 1/15th of a second I was starting to get some significantly blurred shots, as well -- so again, the RX100 III did better than the earlier models.
(Interestingly, to this point the original RX100 also seemed to be doing a little better than the RX100 II, though the difference was fairly slight. There's no obvious reason for this, since they share the same lens and stabilization system. All I can think of to explain this is that I am more familiar with trying to hold that camera's slightly slimmer body steady, since I actually own it.)
At 1/10th of a second or below, sharp shots from the RX100 III were in the minority, but I still got a couple as low as 1/6th second, and only a few were significantly blurred. By contrast, most shots from the RX100 and RX100 II were already unusable at 1/8th of a second or slower, although even these earlier cameras just occasionally managed a sharp shot at fairly low shutter speeds.
All three cameras were capable of sharp handheld exposures at surprisingly low shutter speeds, given five shots in a row to up the odds a little. Here is another 1:1 crop of the slowest sharp image from the RX100 III, shot at 1/6th second.
Overall, the RX100 III turned in more sharp or almost-sharp images at slow shutter speeds than did both earlier models, and it was pretty clear to me that its stabilization system was an improvement.
The slowest shot from the original RX100 showing good detail was at 1/8th second, while the RX100 II -- which seemed to do a fair bit better at really slow shutter speeds -- managed one sharp shot apiece at 1/8th, 1/6th, 1/4, and even 1/2 second. These, though, were rare finds among a morasse of unusably-blurred shots.
While the RX100 III didn't happen to manage any perfectly sharp shots below 1/6th second, I'd put that down more to the luck of the draw than anything else. It got close a few times, scoring a couple of near-misses as slow as 1/2 second, and the shots it captured weren't typically as badly blurred as those from the earlier models at the longer shutter speeds. Arguably, many of them would've been usable for small prints, even a couple that were handheld with a 0.8 second exposure!
So to answer the reader question, yes -- in my opinion I'd say that the RX100 III's stabilization system is noticeably better than that of its siblings. But honestly, I don't see that the earlier models are too shabby, either, as down to say 1/10th or 1/13th second they can still turn in useful shots, and occasionally quite sharp ones at even slower shutter speeds.
I also learned that it's definitely worth shooting several exposures when your shutter speed is slow, even if your subject is quite static. It seemed that in the middle of a five-shot series, I'd usually get better results than I did with the first or last couple of frames. (Which is perfectly logical, as it's harder not to move the camera in anticipation of starting or ending a series, compared to when you've got a rhythm going in the middle of the series.) And these were all captured in single-shot mode -- I'd guess I could've gotten even more usable exposures simply be shooting in continuous mode with the shutter button held down.
Another request from readers was that I discuss the RX100 III's flash options.
Perhaps the most important thing to note is that the hot shoe of the RX100 II is gone, removed in the interests of saving space and making room for the popup viewfinder. Personally, I don't have a problem with that change -- I wouldn't be likely to carry a chunky, external flash strobe when shooting with a small camera like this, as it would negate its portability. And while some cameras come with tiny tilt-up strobes that add little to the camera size, they're typically not much better than built-in strobes in terms of output. At least a built-in strobe won't get left at home by mistake, though.
The popup strobe now sits over the middle of the lens, and that brings it just a little closer to its optical center, but I didn't notice any real difference in terms of red-eye. Like that of the earlier models, it's spring-loaded and can be tilted with a fingertip to serve as a bounce flash -- at least, so long as you have a relatively low ceiling -- although I doubt that it's really an intentional feature of the design.
Since I already had the flowers handy, I used them for a quick test of the RX100 III's flash sync performance too, albeit not the most flatteringly-lit one. Top is a 1/2,000 second exposure with flash, evenly lit across the frame. Beneath is an exposure with identical aperture and shutter speed, but without flash the camera had to push sensitivity from ISO 200 to 6,400, and still couldn't manage the same exposure level.
So yes, dear readers, the RX100 III is still capable of flash sync at all shutter speeds with its internal strobe. Given its lesser-performing strobe and lack of external flash connectivity, though, it's not going to be as useful a feature as with the earlier models.
However, it's also rather less powerful than that of the RX100 and RX100 II, perhaps because of the need to cover a 24mm wide-angle instead of the earlier models' 28mm wide-angle. That means you're going to either need to be closer to your subject to get a usable flash exposure, or to use a higher sensitivity, increasing noise levels. If you're a fan of the bounce flash trick, that's a shame because when you bounce off a ceiling, you're effectively increasing the distance to your subject and likely losing a fair bit of your flash output to the fact that the ceiling won't be a perfect reflector. You'll find that trick less useful than with the RX100 III's siblings.
Now, the good news. I tested, and I confirmed that just as with its predecessors, the Sony RX100 III will sync flash at any shutter speed -- even 1/2,000 second. Again, the reduced flash strength means you'll need to be closer than ever to your subject for fill flash to be useful, but if you're close enough, it should work regardless of shutter speed.
And at this point, I wanted to test what would happen if I used a flash-triggered slave strobe to boost the RX100's output, but sadly I couldn't do so. The reason? I was planning on using my extremely aged Digi-Slave Pro strobe, a modified Vivitar 285 HV made by SR Electronics which I've had for close to 15 years. It's sat unused for quite a while, though, and when I took it out of the box I found that it had finally gone to the big flash strobe graveyard in the sky. Ah well, such is life. That pairing (or one like it) should work, though, allowing off-camera flash within a short distance as well. You'll just have to set your exposure manually, as the RX100 III's metering system won't be expecting the extra flash output.
Wi-Fi and PlayMemories Camera Apps
Among the features which the Sony RX100 II added beyond what's available in my RX100 was in-camera Wi-Fi wireless networking connectivity, plus Near-Field Communications for quick setup with Android devices. (Apple still stubbornly refuses to support the standard in its products, which is a shame given how quick and simple it makes Wi-Fi pairing.)
The RX100 III retains the Wi-Fi and NFC support, and adds Sony's proprietary PlayMemories Camera Apps into the mix. I've used them in the past on some of Sony's other cameras, but it's the first time they've been provided in an RX-series model. They're not what you'd typically think of as "apps", in that third parties can't develop them -- only Sony itself can choose which apps to make available for any given camera. And many of their functions are things that other cameras already offer free of charge, straight out of the box.
Still, a few are fairly unusual -- in some cases even unique. As of this writing, Sony offers a choice of 15 apps for the RX100 III, excluding foreign-language equivalents of the standard English on-screen keyboard. Of these 15 apps, the majority are available for a one-time fee that's additional to the cost of the camera itself, although a few apps -- including one which is arguably the most useful of the bunch -- are free.
The Sony RX100 III's new PlayMemories Camera Apps are of varying utility. Personally, I found the Smart Remote Control app by far the most interesting. Through your smartphone's screen it lets the camera do something that, by itself, it can't: touch autofocus!
Three apps are priced at US$10 apiece, and another six cost US$5 each, potentially adding US$60 to the cost of your camera to get these value-added features. (That's 7.5% of the camera's list price!) Of remaining apps, two are uploaders and three are keyboards, so only the My Best Portrait, Smart Remote Control, Picture Effect+ and Photo Retouch add particularly interesting camera features without any extra cost.
I have to say, I think the pricing is a bit on the steep side. Smartphone apps which can potentially do a whole lot more often run as little as US$1-3, and can follow you from device to device without an extra charge. By contrast, Sony's apps are tied solely to its cameras and many of them only serve a single, relatively narrow purpose. You don't have to buy them, though, so I won't complain too strongly.
The full list of apps available right now for Sony RX100 III owners is My Best Portrait (free), Smart Remote Control (free), Star Trail ($10), Smooth Reflection ($5), Liveview Grading ($10), Flickr Add-on (free), Motion Shot ($5), Portrait Lighting ($5), Light Shaft ($5), Bracket Pro ($5), Time-lapse ($10), Multiple Exposure ($5), Picture Effect+ (free), Photo Retouch (free), Direct Upload (free), and four keyboards -- International, Japanese, Chinese and Korean (all free).
To download, update, or use any of these -- even those which are already installed on the camera -- you'll first need to register for an account on Sony's website, and provide a working email address. You have to sign up from your computer first, and then log in on the camera, a process which is unnecessarily clunky and awkward, particularly if you're a big believer in secure passwords.
The Smart Remote Control app provides a live view feed that's smooth and with minimal lag, at least if your smart devices is fairly near the camera. You can change the live view quality if the connection is problematic, however, reducing bandwidth and hopefully improving the situation.
The on-screen keyboard is about as good as it could be, doing its best to make it obvious which letters you've typed, and whether you've typed the same letter twice in a row. Still, it would be so much easier if Sony simply set the system up so that you typed a code shown on the camera's screen using your PC's physical keyboard, rather than having to hunt-and-peck for letters on an onscreen keyboard without a touch screen, by pressing the four-way controller keys dozens or perhaps hundreds of times.
And it's also a bit curious that the sign-in screens look like regular HTML, rather than being tailored to the camera's display. (You even have to scroll up and down the screen to see the password field beneath that for the username!)
I wanted to be able to say that the good news was you only have to enter your username and password once, but sadly that wasn't the case. While there's a checkbox to remember your username, your password isn't stored in the camera, and I found myself forced to log in a second time after updating the remote control app, without ever disconnecting from my Wi-Fi network, powering the camera off, or even leaving it unattended. Why the need to log in twice in the space of less than two minutes, I'm not quite sure.
But enough of that critique, what of the apps themselves? Well of the bunch, by far the most useful in my opinion is Smart Remote Control, which is thankfully also free. This lets you see a remote live view from your smartphone or tablet's screen, so long as you have the free app installed on Android or iOS devices, of course.
Although you can't switch modes from the app itself, you can do so from the camera body, at which point the variables which can be adjusted change from grey to white text. Tap on the variable and it turns orange, with a tape of available values shown above. Drag side to side on the tape to browse, and then tap the figure you want to make a selection. It's simple and intuitive.
There's minimal lag when the two devices are up close to each other, and it didn't start getting a bit stuttery with my HTC One X+ smartphone until I was at a distance of around 10 feet, plenty to help frame a group portrait before firing the shutter remotely. The connection degraded to the point where I felt it unusable once I'd walked around 30 feet, and put an inside wall in between myself and the camera. That range could likely be improved with a third-party Wi-Fi extender, though.
Although the app won't let you control the exposure mode remotely, it will allow exposure variables (shutter speed, aperture and ISO sensitivity) to be adjusted as applicable in the current shooting mode set on the camera body, and you can change modes with the physical mode dial without first disconnecting the camera. The app also allows remote zoom control, touch focus (adding a handy function which the camera body itself lacks!), and remote shutter release.
Through an on-screen menu, you can also control white balance, self timer, review image size, and live view quality (standard or image quality priority). You can also set how long to review images on the phone or tablet, and whether to automatically save the review image, saving you manually transferring images from camera to smart device if you decide you like them.
This app was a whole lot of fun, and pretty useful too. My second favorite was the Picture Effect+ app, which works on the camera's own screen or viewfinder, and provides quite a range of pre-capture filter effects. They're not particularly unusual, and they greatly curtail the options available to you through the menu system -- most significantly, forcing you to shoot in JPEG mode -- but they do provide a lot of creative freedom without having to rely on your smart device. I did wish that browsing through the options was a bit faster, though.
Once an image is captured, a large review image is shown. By default it's 1,616 x 1,080 pixels in size, giving you a good tradeoff between ability to judge focus and swift file transfer. Smartphone paradigms are respected, so you can for example pinch to zoom and drag to pan this review image.
You can set the smartphone app to retain this image, if you don't need the maximum quality for sharing on social networks straight out of the camera. You can also set the app to simply transfer full-res images instead, however.
In full, the list of Picture Effect+ options is Partial Color+ (converts image to black and white except for one or two user-selected color ranges), High Contrast Mono, Soft Focus (three steps), HDR Painting (a true three-shot HDR with three-step strength control), Rich-tone Mono. (black and white three-shot HDR), Miniature+ (miniature effect in three positions horizontally or vertically; can be combined with retro / toy camera effects), Watercolor, Illustration (three steps), Toy Camera+ (normal, cool, warm, green, magenta; combined with lo, mid or high vignetting), Pop Color, Posterization (color or B&W), Retro Photo, and Soft High Key+ (pink, blue, green).
The remaining free apps I didn't find terribly interesting, nor particularly relevant to the target market for a camera at this price point. Photo Retouch works post-capture, and allows a Soft Skin Effect (but only if a face is detected), image resizing and cropping (called "Framing"), rotation (called Horizontal Adjustment, it has very fine steps and a generous range, but is very slow!), brightness control, contrast control, and saturation control.
My Best Portrait, meanwhile, is a mixture of pre- and post-capture processing. It provides an optional seven-step skin brightening function coupled with optional three-step skin softening. These are set once pre-capture (with a chance to preview the effect by capturing an image), and then your chosen settings are remembered for subsequent shots unless you opt to change them.
Post-capture, you can then add catch-lights to your subject's eyes. There are seven catchlight types (a couple of useful ones, plus a somewhat schmaltzy selection of hearts, stars and so forth), and you can adjust the size, brightness, and position (this last is tweaked separately for each eye). The app doesn't attempt to detect the edge of the eye, so will happily overlap a catchlight onto your subject's eyelids if you let it. The user interface shows you a wider view of your subject's face cropped in to the eye area, as well as closeups of each eye, so you can see reasonably well where you're placing each catch-light.
If I were to buy the camera, I'd probably only bother installing the first two apps, and skip the others -- at least, unless any of the paid apps caught my eye. Those two apps do make the overall feature worthwhile, though, so I'm glad it's been added even if I'm not a huge fan of paying so much for first-party apps on a single-purpose device.
Sony has overhauled the RX100 III's feature set, and it now offers an alluring combination: Much better video quality, and handier performance to boot. Cool! Here, we're looking at a Full HD clip shot at 60 frames per second with XAVC S compression.
Download RX100 III XAVC S-compressed Original
And so we come to the final feature I wanted to test: Video. Here, Sony has made quite a few changes. Perhaps most significantly, the Sony RX100 III now reads off the whole sensor when recording video, and then downsamples post-capture. Most cameras -- the RX100 and RX100 II included -- only read off a small portion of the sensor area, skipping lines in between to reduce the amount of data which needs to be read off and encoded.
It's an approach that saves processor power (and thus money), but it also noticeably degrades image quality, introducing aliasing artifacts and moire. The RX100 III promises much higher-quality video because it doesn't throw data away on readout -- instead, it downsamples the sensor image and crops to match the output aspect, making the best of the available data to maximize image quality.
Unfortunately, this change is accompanied by one significant drawback: There's a focal length crop applied to all high-def video shot with the RX100 III, even if you switch back to AVCHD capture and disable SteadyShot Active stabilization. Of course, the RX100 III's lens is wider than that of earlier models, so in the end it's not as big of a disadvantage as it could have been, but it's still a shame if you're a fan of wide-angle video.
Focal length crop: All three video frames shown here were captured from much the same location. At top is a frame grab from the Sony RX100 II's video. Beneath are RX100 III frame grabs, both 60p (middle) and 120p (bottom).
Even with the RX100 III's wider lens, the earlier camera can capture a wider view because it's using the full sensor width, whereas the newer model crops to a smaller window in the middle of the sensor.
The RX100 III also introduces a new XAVC S video format to the existing AVCHD and MPEG-4 compression options. Again, it promises much higher quality thanks to a huge increase in the bitrates, but you'll need to explicitly enable it, as the camera still defaults to AVCHD. Should you do so, though, you'll gain access to 50MBps capture at 120, 60, 30 or 24 frames per second, where AVCHD mode is limited to 60p / 60i / 24p capture at anywhere from 17 to 28Mbps, depending on the frame rate.
Note, though, that the 120fps mode has an even stronger focal length crop than does regular video shot with the RX100 III. It's also limited to a resolution of 1,280 x 720 pixels, and prevents use of SteadyShot Active-mode stabilization.
Video image quality: Here, we're comparing video quality shot at approximately the same focal length with the RX100 II (left), RX100 III in AVCHD mode (middle) and RX100 III in XAVC S mode (right).
The difference between AVCHD and XAVC S is pretty subtle, but there's a big difference between Sony RX100 II and III video, despite both cameras sharing much the same backside-illuminated sensor design. That difference makes the focal length crop a whole lot easier to live with.
But enough of the theory, would the difference between XAVC S and AVCHD compression be noticeable? That's what I wanted to know, so I took the Sony RX100 III and its predecessor, the RX100 II, to downtown Knoxville for some side-by-side shooting.
Compared to standard AVCHD at its maximum bitrate of 28Mbps, the RX100 III's 50Mbps XAVC S video compression brings a very subtle improvement in image quality, but it's noticeable if you look very carefully. (I found it easiest to notice in fine, repeating patterns like bricks, textures in fabric, etc.) Surprisingly, the difference was still noticeable even after being uploaded to YouTube and recompressed, although again, it was a very subtle difference indeed.
You pay a hefty price for that slightly better video though, because file sizes are literally doubled compared to 28Mbps AVCHD. And your flash card must be fast enough to support XAVC S recording in the first place, too; I tried a Class 6 card out of curiosity, and on trying to change file type, received a warning that "This memory card does not support recording of XAVC S movies." At least the warning is immediate, rather than a last-minute surprise when you capture a video. (Smart move, Sony!)
The RX100 III features Sony's SteadyShot Active stabilization (or at 120 fps, standard SteadyShot). At wide-angle, SteadyShot Active can steady significant motion such as walking pretty easily; once you zoom in it struggles to keep things steady.
Personally, I don't think I'd bother with XAVC S most of the time, but if I thought there was any chance of wanting to extract a still image later, or of needing to crop the video significantly -- perhaps to stabilize further in software beyond what the camera itself can already do -- I might switch to XAVC S on a case-by-case basis.
The difference between the RX100 III's XAVC S or AVCHD modes and the AVCHD output of the RX100 II using much the same sensor, though, was much more noticeable. Comparing still frames, the RX100 III is just a little sharper than its sibling. Watch live video, though, and that slight improvement in sharpness feels like somebody's just switched off a soft-focus filter. Everything suddenly seems clearer and more high-definition, and little artifacts in fine patterns like bricks that you didn't notice in the still image comparison -- but which were quite obvious in video -- suddenly vanish.
As for the 120-fps, 720p video, I also gave that a try. I already mentioned its drawbacks -- a reduction in resolution, an even stronger focal length crop, and an inability to use SteadyShot Active stabilization -- but the plus is either smoother motion (albeit sometimes accompanied by a perception of stuttering because the faster shutter speeds prevent your subject having as much motion blur), or the ability to slow down your video while retaining a high frame rate. You can manage 0.5x slow-motion playback while still retaining smooth 60p motion, or drop all the way to 30p for 0.25x slow-motion, and it's nice to have that option.
The RX100 III's 120 fps mode plays at full speed by default, but if your software allows, you can slow it to 60 fps for a 0.5x slow-mo effect, or 30 fps for a 0.25x slow-mo.
All things considered, I think these changes make the Sony RX100 III a much more interesting proposition for video than its predecessors, even if it applies a greater focal length crop than they do. There's one change I'm not so keen on, though.
The Sony RX100 III's flash card folder structure is more ludicrously convoluted than ever. Just placing a card in the camera and formatting it will use 52MB of card space, before you've shot a single image or movie clip. (OK, flash card space is cheap these days, but it still feels wasteful.)
Browse the just-formatted card and you'll find a total of at least 11 folders, seven of them nested three folders deep. Shoot a single image, and five more folders will appear. Depending on the file format, your videos are stored in one of three different locations. It's as if somebody intentionally planned to make the card layout confusing, in the hopes of persuading you to use an app to offload your data, rather than doing it by hand.
Night video shot at 60 frames per second with the Sony RX100 III in AVCHD mode.
The new XAVC S videos all come accompanied both by an XML file detailing things like camera model, duration and frame count, and a 1,280 x 720 pixel downsampled frame from the start of the video, each consuming around 300-500KB apiece. Again, that can burn through space quickly if you shoot a lot of short video clips.
These are, it has to be said, relatively minor criticisms, however. All things considered, the improvement in sharpness on offer from the Sony RX100 III's video is noticeable enough that if you're a fan of HD video and don't need an extreme wide-angle, I'd recommend this camera over the RX100 or RX100 II in a heartbeat. Video from the RX100 III is simply more pleasant to watch, even if you forgo its XAVC S video compression.
As always, my final word will come in the conclusion of this review. Before I wrap up this final Field Test, however, I wanted to share a few closing thoughts.
When I started this review, I noted that I owned the RX100 III's earliest predecessor, the RX100. There's a lot that's changed between those two cameras, and I have to say that I appreciate most of those changes. While the new camera is a little bulkier than its siblings, and its lens doesn't have as much reach, I found that I mostly forgot about those drawbacks pretty quickly.
Compared to the earlier cameras, though, there's a big step forward in the camera's performance and capabilities, and the brighter lens really pays dividends towards telephoto in low light.
Were I in the market for a new camera today, I'd definitely look to the Sony RX100 III, rather than the earlier models -- at least if I could afford the extra cost. As an RX100 owner, I must admit that I'm tempted to upgrade. If I could afford to do so right now, I probably would.
If you're considering an RX-series camera, my advice to you is to go for the RX100 III, and get shooting already. It's a lot of fun shooting with a camera this compact and convenient, and yet getting such great images!