Testing: Sony RX100 MK III Compact Camera

By Norman Chan

Ending my quest to find a perfect pocket camera to complement my DSLR.

I've been on the hunt for a pocket camera to complement my DSLR, and spent time with cameras with sensors ranging from micro 4/3 to full-frame. My test of Sony's RX100 Mark II made me seriously consider the trade off between body size and sensor size. There were several things that held it back from being ideal for my day to day use, but I realized that getting a compact camera with an APS-C or Full-Frame sensor would compete too directly with my DSLR. Going for portability made more sense for a secondary camera. So for my recent birthday, I ended up buying Sony's RX100 Mark III, based on the praise other photographers have given it. It arrived a little over a week ago, and I've been shooting a lot with it since. And even though I've already committed to the camera, I'm still running it through the practical testing that I would give any new camera to gauge its strengths and weakness, and to relay that experience to you. So here's what that shooting experience has been like so far.

One of the reasons I felt I would be comfortable buying the RX100 III before using it is because it inherits almost all of the great things I like about the RX100 II. That includes size, weight, tilting LCD, image quality, manual controls, and wi-fi features. The size and weight are perfect for these cameras to be stowed in a jacket pocket (though the MK III is slightly thicker and heavier than both previous models). I was already satisfied with the RAW and JPEG image quality from Sony's 20MP 1" -type sensor, even if the lens on the MK II was a little lacking. And I have been very impressed with the Wi-Fi connectivity of Sony's cameras, which I used extensively on the a7 and RX100 II. In using this 3rd-generation RX100 the things I wanted to specifically test for were the new zoom lens and autofocus speed, as well as the digital viewfinder.

The OLED viewfinder is probably the most noticeable addition to the RX100 line, and surprisingly doesn't add to the heft or bulk of the camera. There's still a built-in flash, and the only thing you lose is a hotshoe that was on the MK II. This EVF pops up on the left side and needs to be extended a little bit before use, so you can't switch to it as instantaneously as you would a fixed EVF like on the Fuji cameras. The eye proximity sensor has proven to be accurate, though. I found the 800x600 resolution (100% coverage, .59x magnification) sufficient for framing and focusing, since I use digital peaking assists anyway for finding focus. I know some people who only use EVFs for their shooting, but I typically can't stand the latency--my brain wants the response of an optical viewfinder. But I have been using the EVF on this MKIII outdoors and even for reviewing photos. If Sony offered a version of the MK III without the EVF for a lower price, I would've gone with that one. But the $150 price difference between the models accounts for the EVF, the new lens, and new processor.

Below are my sample photos taken so far, with notes on what they say about the camera. The photos were not post-processed at all, just RAW files ingested in Lightroom and resized/exported as JPEGs. Click each of them to enlarge.

Testing Photos and Notes

Macro shot at f/1.8, ISO 125

One of the first things I do with every new camera is test it at my desk, in a macro photo. Here's my obligatory toy photo, shot wide open at f/1.8 and the lowest ISO setting. I do this to test a few things: the minimum focus distance (how close I can bring the lens to the subject), the sharpness at widest aperture, and the image quality at lowest ISO. The RX100 III can get inches away from the subject at 24mm, bokeh looks good with the 1"-type sensor and f/1.8, and ISO 125 is extremely clean, as expected. Luigi is pleased so far.

One thing I noticed when taking a few more macro shots is that the sharpness does decrease as you widen the aperture. A macro photo taken at f/1.8 below shows some fuzziness in the edges, even at the places where the photo is supposed to be in focus (look at the letters in the app names).

This isn't uncommon in wide-aperture lenses--my Sigma 50mm f/1.4 does the same thing. Stopping down to f/2.8 or 3.2 improves sharpness dramatically. The photo below is shot at f/3.2 and looks great. I found that f/2.8 was a good sweet spot for the lens, and only stopped down to f/1.8 when I needed to get more light and didn't want to raise the ISO.

The new lens in the RX100 III is a LOT better than the one in the MK II. The focal range of the lens has changed from 28-100mm to 24-70mm (35mm equivalent), so it doesn't zoom as far. But the benefit is that the aperture only drops down to f/2.8 when zooming in, as opposed to the f/4.9 of the previous models. With f/2.8, I could take low-light photos indoors without having to crank the ISO past 1600 or keep the lens wide at 24mm. The photo below was taken at f/2.8 and ISO 800 at 1/30s. I shot in burst drive to compensate for the relatively slow shutter and didn't get many blurry shots.

For most of my indoor shots, auto-ISO kept the camera at around 1600-2000 ISO at night. The next series of photos shows some high ISO testing, capped at ISO 6400. Again, I didn't do any post processing to these yet to reduce noise, and still find that ISO 2000 looks good.

ISO 2000 Indoors:

ISO 2000 outdoors:

ISO 3200 at 1/400s to capture the liquid nitrogen steam. Still usable at this point.

ISO 6400, which starts to look pretty gnarly:

I also did some testing of the continuous shooting capabilities of the camera for subjects in motion. I normally don't shoot in continuous drive with Speed Priority, so am still getting used to what shutter speeds to use for different types of moving subjects. For example, I thought that 1/200s would be sufficient for a dog in motion, but still got some blurring in the paws:

A good test opportunity came about this past weekend when I went to the racetrack with some friends. I experimented shooting at 1/1600s shutter to catch the race, using the Speed Priority mode to bump the RAW recording framerate from 2.7fps to about 6fps. If you just save as JPEGs, the RX100 III can shoot up to 10fps. Shooting in Speed Priority means the exposure and focus are locked from the first shot, which was fine for stationary shooting of the track. I was pleased by the images I got:

I'll have more thoughts about shooting in Speed Priority in a future column, but one thing I wish this camera had was the ability to set a minimum shutter speed with the auto-ISO setting. I like shooting in Aperture Priority (camera always chooses widest aperture for exposure), and bracket my auto-ISO to avoid the noiser settings. But that often sets the shutter to 1/30 as a floor before the camera bumps up ISO, when I'd prefer to be able to configure that floor for different situations (eg. 1/80 for portraits, 1/320 for animals). Some of you have recommended that I shoot in full Manual mode with auto-ISO, but that doesn't let me choose to exposure compensate when I would prefer to have the trade-off between underexposing by a third of two-thirds stop to keep ISO low. I like the system the Canon 5D III has for its auto-ISO and min. shutter settings.

More Testing to Come

I've been using the RX100 III a lot in the past week, often choosing it over my Canon for daily tasks like taking product photos for posts on the site. The new lens makes a big difference in shooting, and f/2.8 at 70mm looks really good. I'll be doing more testing before shooting a video review, but am feeling pretty happy with the purchase so far. And of course, the camera takes great derpy dog photos.