Sony Cyber-Shot DSC-RX100: Performance

November 30, 2012 by Jim Keenan Reads (144,299)
Editor's Rating

Ratings Breakdown (1-10)

    • Image/Video Quality
    • 9
    • Features
    • 8
    • Design / Ease of Use
    • 9
    • Performance
    • 9
    • Expandability
    • 8
    • Total Score:
    • 8.60
    • Rating 1 to 10, top score 10


Sony describes the RX100 as an outstanding choice for the DSLR owner looking for a high-quality, pocket-sized second camera. Let’s see how the ad copy stacks up against reality.

Shooting Performance
The RX100 presents a shooting screen about two seconds after power up and I was able to get off a first shot in about 2.75 seconds. Single shot to shot times are basically as quickly as you can take the shot, reacquire focus and shoot again. The camera offers two continuous shooting modes: low and speed priority. Low produced an approximately 2.5 fps rate for about 35 JPEG fine images before the shooting speed slowed. Sony claims speed priority produces up to 10 fps at full resolution, but our studio measurement came up at 11.4 fps, and this for 13 images before shooting slowed. My shooting in the field in speed priority more closely matched the Sony claim as to speed, and the most JPEGs I saw was 9 before shooting slowed. The discrepancy in frames is not surprising as some scenes have much more detail than others, which results in larger files and can affect buffer capacity, but try as I might I couldn’t get the 11+ fps figure. Rest assured that with an appropriately quick shutter speed the RX100 will deliver on that 10 fps claim, if only for about a second.

Write time to completely clear the buffer for those nine images took about 8.75 seconds (using a 16 GB 633x SDHC UHS-1 card), but the camera will allow you to capture more images as soon as there is any room in the buffer. Switch the RX100 into RAW/JPEG mode and you get about four images before things slow at speed priority; low produced nine images before things slowed.

AF Acquisition (press-to-capture, no pre-focus)

Camera Time (seconds)
Fujifilm FinePix F600EXR 0.14
Nikon Coolpix P7100 0.19
Sony Cyber-shot RX100 0.26
Canon G1X 0.65

Continuous Shooting

Camera Frames Framerate
Sony Cyber-shot RX100 13 11.4 fps
Canon G1X 5.6 fps
Fujifilm FinePix F600EXR 4 3.5 fps
Nikon Coolpix P7100 1.2 fps

peak brightness 467 nits
black luminance 0.88 nits
530:1 overall contrast ratio

*Note: Continuous shooting framerates are based on the camera’s fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). “Frames” notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

Shutter lag seemed good in the field and was corroborated by our studio measurement of .01 seconds. Sony claims autofocus acquisition times as quick as .13 seconds, but our studio measurements produced a .26 second time. Frankly, the camera felt faster than this most of the time in good light, and was one of the faster focusing compact digitals I’ve ever reviewed. The camera retains a fairly quick autofocus acquisition capability as light dims and the focus assist lamp worked well out to about 10 feet in virtually pitch black conditions.

Switching into continuous autofocus produced an interesting effect – the image on the monitor would pulsate slightly as you held a half push to acquire and maintain focus, almost like the lens was zooming a tiny bit in and out. Whether that is symptomatic of the RX100 in general or a camera specific behavior of our review model (which clearly had seen some hard use before it reached us based on the scratches adorning the monitor) is not clear, but this didn’t seem to affect continuous autofocus tracking of moving subjects. My wife drove down to the end of the block (about 100 yards) and then began driving towards my position. I acquired focus as she began to move towards me and began shooting in low speed continuous mode with continuous autofocus enabled. I tracked her and the vehicle for a total of 12 frames, covering a distance of about 150 yards with the closest approach to me of about 30 feet, and every frame displayed sharp focus.

Sony doesn’t list a guide number for the built-in flash on the RX100, but claims coverage up to about 56 feet at auto ISO and wide-angle; coverage is up to about 20.7 feet at telephoto. Coverage at 6400 ISO is listed as about 79.3 feet and 29 feet, respectively. Flash recycle times ran a bit over three seconds in automatic shooting modes where the camera was free to set ISO; setting ISO at 80 and aperture priority with the lens stopped completely down to promote a full discharge of the flash resulted in recycle times a bit over five seconds.

Sony rates the battery life of the RX100 as 330 shots; the battery must be recharged in the camera and full charge of a depleted battery takes approximately 155 minutes. Sony’s press release on the RX100 mentions new accessories including a battery charger, but no such item appears currently on Sony’s website. There are third-party batteries and chargers available on the Internet but we were unable to test their viability. Once again, given the cost of the RX100, one would have hoped that Sony would have opted to forgo the charge in the camera routine and instead provided an external charger.

Lens Performance
Carl Zeiss lenses have typically shown fairly good performance in compact digital cameras that I’ve reviewed, and the Vario-Sonar T in the RX100 kept this string alive. The lens produced a sharp image at wide-angle center with some softness in the edges and corners and perhaps just a tiny bit of light falloff in the corners; telephoto was equally sharp in the center and perhaps even a bit better in the edges and corners than at wide-angle. There was no distortion to speak of at wide-angle, in the middle of the focal range or at telephoto — no worries about horizon lines or other straight lines in images getting bent by lens distortion.

The wide-angle end of the lens showed some chromic aberration (purple fringing) in some high contrast boundary areas, but this defect was most prominent only at enlargements in the 200 to 300+ % enlargement range. The telephoto end of the lens was virtually free of this defect. Admittedly, a 3.6x zoom is a fairly simplified engineering exercise compared to producing a 20 or 30x-plus lens, but the RX100 lens is a very solid performer, one of the best I’ve seen in a compact digital camera.

Video Quality
Full HD video quality out of the RX100 was very good, and the autofocus did a good job of keeping the picture sharp when going from a near to distant subject, and vice versa. The camera is susceptible to wind noise but there is a wind cut feature, and the camera will on occasion record some sounds associated with zooming the lens. Because it utilizes a CMOS sensor, the RX100 can be susceptible to rolling shutter effect but Sony has done a pretty good job of minimizing this defect. Rolling shutter was present during exaggeratedly high speed pans, but these were certainly much faster than would be the norm in most cases. Pan with one of the Blue Angels on a high-speed pass with trees in the background and you might see some distortion, but just about anything else shouldn’t pose a problem.

Image Quality
Default image quality out of the RX100 was quite pleasing with regards to sharpness and color rendition.

JPEG fine quality was quite good, with little if any JPEG artifacts being readily discernible in most cases. As this is written, Adobe products such as Lightroom and Photoshop reportedly do not support the RX100 RAW format (my Photoshop CS5 certainly doesn’t) and there is no in camera raw converter. Sony’s website provides an image data converter that may be downloaded to allow you to process RX100 RAW files, but I have to question why Sony didn’t simply provide this RAW processing capability with a bundled CD. The Sony image data converter allows you to save RX100 RAW images as either JPEG or TIFF files, both of which are recognized by existing software such as Photoshop. Here are two JPEGs – one is a JPEG Fine out of the camera and the second is a RAW file saved as the highest quality JPEG via the Sony image data converter.

The camera also offers a 13 option “picture effect” menu with choices such as toy camera, pop, poster’s Asian color, retro photo, soft high key, partial color (red, green, blue, or yellow), high contrast mono, soft focus (low, mid or high), HDR painting (low, mid or high), rich tone mono, miniature (with the effect applied to the top, middle, or bottom), watercolor, or illustration (low, mid or high). The picture effect menu is not available when the camera is set for either the RAW or RAW/JPEG image capture formats – JPEG fine or standard quality only.

Shooters in the manual modes have access to DRO (dynamic range optimizer) and HDR (high dynamic range) settings (enabled by default) to help expand the apparent dynamic range of the camera. The settings are mutually exclusive- you can enable one or the other, but not both simultaneously – and offer automatic or manually established levels of compensation. It is important to note that with DRO enabled the shutter may stay open for a relatively lengthy period in dimmer lighting conditions; with HDR multiple images are captured and again, in dim light, the shutter on individual images in the sequence may stay open for a long time. Shooting with either of these options enabled in less than bright conditions is best accomplished with a tripod or other means of camera support.

Sony RX100 Sample Image
Auto White Balance, 5500k fluorescent light

I used auto white balance for all the images captured for this review and in general it did a good job across a variety of lighting including daylight, cloud, open shade and flash. In addition to the automatic setting there are daylight, shade, cloudy, incandescent, four fluorescent (warm, cool, day white and daylight) and flash presets along with color temperature and custom settings.

Multi metering is the default setting and appropriate for most situations; I used the default for all the images captured for this review. This setting worked well overall but in some instances of high contrast could clip highlights, a not uncommon occurrence for compact digital cameras. There are center weighted and spot metering options available for shooters in the manual modes.

While I generally avoid even discussing digital zoom features on compact cameras, the RX100 offers what Sony calls Clear Image Zoom in addition to the typical digital zoom. Where the typical digital zoom performs an electronic crop to magnify pixel size and create a longer telephoto effect (lowering sharpness and producing image degradation), the Sony system performs an electronic crop, but then analyzes the image to digitally create pixels and match patterns, a process which Sony says retains pixel numbers and the image quality of an optical zoom. A Sony training bulletin backs off the image claim just a bit, describing image degradation as “almost imperceptible.”

Pixel peeping on the original images I found the clear image zoom shots didn’t look quite as good as the optical images, but they did look better than typical digital zoom captures. If all else failed and you had to have a closer perspective I’d use the clear image zoom, but good as it is it still falls a bit short of a true optical capture.

Sony RX100 Sample Image
ISO 100
Sony RX100 Sample Image
ISO 100, 100% crop
Sony RX100 Sample Image
ISO 200
Sony RX100 Sample Image
ISO 200, 100% crop
Sony RX100 Sample Image
ISO 400
Sony RX100 Sample Image
ISO 400, 100% crop
Sony RX100 Sample Image
ISO 800
Sony RX100 Sample Image
ISO 800, 100% crop
Sony RX100 Sample Image
ISO 1600
Sony RX100 Sample Image
ISO 1600, 100% crop
Sony RX100 Sample Image
ISO 3200
Sony RX100 Sample Image
ISO 3200, 100% crop
Sony RX100 Sample Image
ISO 6400
Sony RX100 Sample Image
ISO 6400, 100% crop

While the RX100’s native ISO range includes low end sensitivities of 80, 100 and 125, in practice these three settings are virtually identical and impossible to tell apart so we chose to use 100 as the starting point for our ISO comparison. With a sensor the same size as that of my Nikon 1 but carrying twice the resolution, I was naturally curious what Sony had accomplished in the high ISO noise performance arena with an extra nine months plus of additional development time before bringing the RX100 to market. The answer, it would seem, is quite a bit.

Besides the obvious doubling of resolution, the RX100’s 6400 ISO sensitivity is a complete EV greater than the Nikon’s 3200. In a simple comparison of noise at 1600 and 3200 the Nikon 1 and the RX100 are really quite similar, but all that extra resolution in the Sony holds some of the fine details better than the Nikon. So, considering it’s the same size but with twice the resolution of the Nikon 1 sensor, Sony has done a terrific job with the RX100 sensor, even with it being a later generation technology.

Looking at the individual ISO sensitivities in the Sony alone, 100, 200 and 400 are virtually indistinguishable and can be shot interchangeably. 800 shows just a hint of graininess here and there, with a few fine details impacted slightly. 1600 shows a bit more pronounced grain and some fine details are beginning to fall off a bit more, although this sensitivity is still quite good overall. 3200 is a bit grainier than 1600 and some fine details are impacted just a bit more, but 1600 and 3200 are actually quite comparable to my eye. 6400 represents a fairly dramatic deterioration from 3200, with increased graininess and fine details are now being smudged in most places on the image. 6400 is best left for those occasions when that sensitivity is the only way to make a viable picture.

Additional Sample Images

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