Sony A5100 vs RX100 III
The Sony Alpha A5100 and the Sony Cyber-shot DSC-RX100 III are two digital cameras that were revealed to the public, respectively, in August 2014 and May 2014. The A5100 is a mirrorless interchangeable lens camera, while the RX100 III is a fixed lens compact. The cameras are based on an APS-C (A5100) and an one-inch (RX100 III) sensor. The A5100 has a resolution of 24 megapixels, whereas the RX100 III provides 20 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A5100 and the Sony Cyber-shot DSC-RX100 III? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.
An illustration of the physical size and weight of the Sony A5100 and the Sony RX100 III is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth measures are rounded to the nearest millimeter.
The A5100 can be obtained in two different colors (black, white), while the RX100 III is only available in black.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony RX100 III is notably smaller (15 percent) than the Sony A5100. In this context, it is worth noting that neither the A5100 nor the RX100 III are weather-sealed.
The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX100 III has a lens built in, whereas the A5100 is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup. You can compare the optics available for the A5100 and their specifications in the Sony E-Mount Lens Catalog.
Concerning battery life, the A5100 gets 400 shots out of its NP-FW50 battery, while the RX100 III can take 320 images on a single charge of its NP-BX1 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Sony A5100||110 mm||63 mm||36 mm||283 g||400||n||Aug 2014||549|
|2.||Sony RX100 III||102 mm||58 mm||41 mm||290 g||320||n||May 2014||799|
|3.||Canon G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|4.||Sony RX100 VII||102 mm||58 mm||43 mm||302 g||260||n||Jul 2019||1,199|
|5.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|6.||Sony A5000||110 mm||63 mm||36 mm||269 g||420||n||Jan 2014||449|
|7.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|8.||Sony A3000||128 mm||91 mm||85 mm||411 g||470||n||Aug 2013||329|
|9.||Sony NEX-3N||110 mm||62 mm||35 mm||269 g||480||n||Feb 2013||499|
|10.||Sony NEX-5T||111 mm||59 mm||39 mm||276 g||330||n||Aug 2013||699|
|11.||Sony RX100 II||102 mm||58 mm||38 mm||281 g||350||n||Jun 2013||749|
|12.||Sony NEX-F3||117 mm||67 mm||42 mm||314 g||470||n||May 2012||599|
|13.||Sony RX100||102 mm||58 mm||36 mm||240 g||330||n||Jun 2012||649|
|14.||Sony NEX-3||117 mm||62 mm||33 mm||297 g||330||n||May 2010||599|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down.
The size of the imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixels in a sensor of the same technological generation. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Sony A5100 features an APS-C sensor and the Sony RX100 III an one-inch sensor. The sensor area in the RX100 III is 68 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 2.7. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
With 24MP, the A5100 offers a higher resolution than the RX100 III (20MP), but the A5100 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 2.41μm for the RX100 III) due to its larger sensor. Moreover, the A5100 is a somewhat more recent model (by 3 months) than the RX100 III, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.
The resolution advantage of the Sony A5100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A5100 for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Sony RX100 III are 27.4 x 18.2 inches or 69.5 x 46.3 cm for good quality, 21.9 x 14.6 inches or 55.6 x 37.1 cm for very good quality, and 18.2 x 12.2 inches or 46.3 x 30.9 cm for excellent quality prints.
The A5100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Sony Alpha A5100 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Cyber-shot DSC-RX100 III are ISO 100 to ISO 12800, with the possibility to increase the ISO range to 80-25600.
For many cameras, data on sensor performance has been reported by DXO Mark. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under review, the A5100 provides substantially higher image quality than the RX100 III, with an overall score that is 13 points higher. This advantage is based on 1.4 bits higher color depth, 0.4 EV in additional dynamic range, and 1.4 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
| DXO |
|2.||Sony RX100 III||1-inch||20.0||5472||3648||1080/60p||22.4||12.3||495||67|
|3.||Canon G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|4.||Sony RX100 VII||1-inch||20.0||5472||3648||4K/30p||21.8||12.4||418||63|
|5.||Sony RX100 IV||1-inch||20.0||5472||3648||4K/30p||22.8||12.6||591||70|
|11.||Sony RX100 II||1-inch||20.0||5472||3648||1080/60p||22.5||12.4||483||67|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, and both provide the same movie specifications (1080/60p).
Beyond body and sensor, cameras can and do differ across a range of features. For example, the RX100 III has an electronic viewfinder (1440k dots), which can be very helpful when shooting in bright sunlight. In contrast, the A5100 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Sony A5100 and Sony RX100 III in connection with corresponding information for a sample of similar cameras.
|2.||Sony RX100 III||1440||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
|3.||Canon G7 X||none||n||3.0||1040||tilting||Y||1/2000s||6.5||Y||Y|
|4.||Sony RX100 VII||2359||n||3.0||921||tilting||Y||1/2000s||90.0||Y||Y|
|5.||Sony RX100 IV||2359||n||3.0||1228||tilting||n||1/2000s||16.0||Y||Y|
|11.||Sony RX100 II||optional||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A5100 has a touchscreen, while the RX100 III has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.
Concerning the storage of imaging data, both the A5100 and the RX100 III write their files to SDXC or Memory Stick PRO Duo cards. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.
For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Sony Alpha A5100 and Sony Cyber-shot DSC-RX100 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony RX100 III||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|3.||Canon G7 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|4.||Sony RX100 VII||-||stereo||mono||Y||-||micro||2.0||Y||Y||Y|
|5.||Sony RX100 IV||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|11.||Sony RX100 II||Y||stereo||mono||-||-||micro||2.0||Y||Y||-|
The A5100 is a recent model that features in the current product line-up of Sony. In contrast, the RX100 III has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the RX100 III was succeeded by the Sony RX100 IV. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony website.
So how do things add up? Is there a clear favorite between the Sony A5100 and the Sony RX100 III? Which camera is better? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Sony Alpha A5100:
- More detail: Offers more megapixels (24 vs 20MP) with a 10% higher linear resolution.
- Better image quality: Scores substantially higher (13 points) in the DXO overall assessment.
- Richer colors: Generates images with noticeably better colors (1.4 bits more color depth).
- Better low-light sensitivity: Requires less light for good images (1.4 stops ISO advantage).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
- More flexible: Accepts interchangeable lenses, so that lens characteristics can be altered.
- Longer lasting: Can take more shots (400 versus 320) on a single battery charge.
- More modern: Is somewhat more recent (announced 3 months after the RX100 III).
Advantages of the Sony Cyber-shot DSC-RX100 III:
- Easier framing: Has an electronic viewfinder for image composition and settings control.
- More detailed LCD: Has a higher resolution rear screen (1229k vs 922k dots).
- Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
- Ready to shoot: Has an integrated lens, whereas the A5100 necessitates an extra lens.
- More compact: Is smaller (102x58mm vs 110x63mm) and will fit more readily into a bag.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- More heavily discounted: Has been on the market for longer (launched in May 2014).
If the number of relative strengths (bullet points above) is taken as a guide, the A5100 emerges as the winner of the contest (10 : 7 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro shooter. Hence, the decision which camera is best and worth buying is often a very personal one.
How about other alternatives? Do the specifications of the Sony A5100 and the Sony RX100 III place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best Travel-Zoom Camera listings whether the two cameras rank among the cream of the crop.
In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A5100 or the RX100 III. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.
This is why hands-on reviews by experts are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera review sites (amateurphotographer [AP], cameralabs [CL], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.
|1.||Sony A5100||4.5/5||+||..||4.5/5||5/5||Aug 2014||549|
|2.||Sony RX100 III||5/5||+ +||82/100||4.5/5||5/5||May 2014||799|
|3.||Canon G7 X||4/5||+ +||77/100||4.5/5||4.5/5||Sep 2014||699|
|4.||Sony RX100 VII||4.5/5||..||..||4/5||5/5||Jul 2019||1,199|
|5.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|6.||Sony A5000||3/5||+||..||4.5/5||4.5/5||Jan 2014||449|
|7.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|8.||Sony A3000||3/5||+||..||4/5||4/5||Aug 2013||329|
|9.||Sony NEX-3N||3/5||..||..||4.5/5||4.5/5||Feb 2013||499|
|10.||Sony NEX-5T||..||..||..||4.5/5||4.5/5||Aug 2013||699|
|11.||Sony RX100 II||5/5||+ +||79/100||4.5/5||4.5/5||Jun 2013||749|
|12.||Sony NEX-F3||4/5||..||74/100||4.5/5||4.5/5||May 2012||599|
|13.||Sony RX100||5/5||+ +||78/100||4/5||5/5||Jun 2012||649|
|14.||Sony NEX-3||..||..||70/100||4.5/5||4/5||May 2010||599|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
Other camera comparisons
Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just use the search menu below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Sony A5100 vs Sony RX100 III
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Sony A5100||Sony RX100 III|
|Camera Type||Mirrorless system camera||Fixed lens compact camera|
|Camera Lens||Sony E mount lenses||24-70mm f/1.8-2.8|
|Launch Date||August 2014||May 2014|
|Launch Price||USD 549||USD 799|
|Sensor Specs||Sony A5100||Sony RX100 III|
|Sensor Format||APS-C Sensor||1" Sensor|
|Sensor Size||23.5 x 15.6 mm||13.2 x 8.8 mm|
|Sensor Area||366.6 mm2||116.16 mm2|
|Sensor Diagonal||28.2 mm||15.9 mm|
|Sensor Resolution||24 Megapixels||20 Megapixels|
|Image Resolution||6000 x 4000 pixels||5472 x 3648 pixels|
|Pixel Pitch||3.91 μm||2.41 μm|
|Pixel Density||6.55 MP/cm2||17.18 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/60p Video||1080/60p Video|
|ISO Setting||100 - 25,600 ISO||100 - 12,800 ISO|
|ISO Boost||no Enhancement||80 - 25,600 ISO|
|Image Processor||BIONZ X||BIONZ X|
|DXO Sensor Quality (score)||80||67|
|DXO Color Depth (bits)||23.8||22.4|
|DXO Dynamic Range (EV)||12.7||12.3|
|DXO Low Light (ISO)||1347||495|
|Screen Specs||Sony A5100||Sony RX100 III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||1440k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||922k dots||1229k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Sony A5100||Sony RX100 III|
|Focus System||On-Sensor Phase-detect||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/2000s|
|Continuous Shooting||6 shutter flaps/s||10 shutter flaps/s|
|Fill Flash||Built-in Flash||Built-in Flash|
|Storage Medium||MS or SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Single card slot|
|UHS card support||UHS-I||UHS-I|
|Connectivity Specs||Sony A5100||Sony RX100 III|
|External Flash||no Hotshoe||no Hotshoe|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||micro HDMI|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||NFC built-in||NFC built-in|
|Body Specs||Sony A5100||Sony RX100 III|
|Battery Life (CIPA)||400 shots per charge||320 shots per charge|
|In-Camera Charging||USB charging||USB charging|
110 x 63 x 36 mm
(4.3 x 2.5 x 1.4 in)
102 x 58 x 41 mm
(4.0 x 2.3 x 1.6 in)
|Camera Weight||283 g (10.0 oz)||290 g (10.2 oz)|
Did you notice an error on this page? If so, please get in touch, so that we can correct the information.