Sigma fp vs Sony A7S III
The Sigma fp and the Sony Alpha 7S III are two digital cameras that were officially introduced, respectively, in July 2019 and July 2020. Both the fp and the A7S III are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The Sigma has a resolution of 24 megapixels, whereas the Sony provides 12 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 Sigma fp and the Sony Alpha 7S 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.
The side-by-side display below illustrates the physical size and weight of the Sigma fp and the Sony A7S III. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth dimensions are rounded to the nearest millimeter.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7S III is considerably larger (56 percent) than the Sigma fp. Moreover, the A7S III is substantially heavier (66 percent) than the fp. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.
The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.
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 would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
|1.||Sigma fp||113 mm||70 mm||45 mm||422 g||280||Y||Jul 2019||1,899|
|2.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|3.||Fujifilm X-Pro3||141 mm||83 mm||46 mm||497 g||440||Y||Oct 2019||1,799|
|4.||Leica M10-P||139 mm||80 mm||39 mm||660 g||210||Y||Aug 2018||7,995|
|5.||Leica SL||147 mm||104 mm||39 mm||847 g||400||Y||Oct 2015||7,450|
|6.||Nikon D780||144 mm||116 mm||76 mm||840 g||2260||Y||Jan 2020||2,299|
|7.||Panasonic S5||133 mm||98 mm||82 mm||714 g||440||Y||Sep 2020||1,999|
|8.||Panasonic S1||149 mm||110 mm||97 mm||1017 g||400||Y||Feb 2019||2,499|
|9.||Panasonic S1H||151 mm||114 mm||110 mm||1052 g||400||Y||May 2019||3,999|
|10.||Panasonic TS7||117 mm||76 mm||37 mm||319 g||300||Y||May 2018||449|
|11.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|12.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|13.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|14.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|15.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|16.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|17.||Sony A7||127 mm||94 mm||48 mm||474 g||340||Y||Oct 2013||1,699|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will naturally be influenced heavily by the price. 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. The fp was launched at a markedly lower price (by 46 percent) than the A7S III, which puts it into a different market segment. 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
The size of the imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better 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.
Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. The sensor area in the A7S III is 1 percent smaller. They nevertheless have the same format factor of 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
Technology-wise, both cameras are equipped with BSI-CMOS (Backside Illuminated Complementary Metal–Oxide–Semiconductor) sensors.
With 24MP, the fp offers a higher resolution than the A7S III (12MP), but the fp has smaller individual pixels (pixel pitch of 5.98μm versus 8.40μm for the A7S III). Moreover, the A7S III is a somewhat more recent model (by 1 year) than the fp, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the fp has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sigma fp implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the fp 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 A7S III are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.
The Sigma fp has a native sensitivity range from ISO 100 to ISO 25600, which can be extended to ISO 6-102400. The corresponding ISO settings for the Sony Alpha 7S III are ISO 80 to ISO 102400, with the possibility to increase the ISO range to 40-409600.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|1.||Sigma fp||Full Frame||24.0||6000||4000||4K/30p||..||..||..||..|
|2.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|4.||Leica M10-P||Full Frame||23.8||5952||3992||none||..||..||..||..|
|5.||Leica SL||Full Frame||24.0||6000||4000||4K/30p||25.0||13.4||1821||88|
|6.||Nikon D780||Full Frame||24.3||6048||4024||4K/30p||..||..||..||..|
|7.||Panasonic S5||Full Frame||24.0||6000||4000||4K/60p||..||..||..||..|
|8.||Panasonic S1||Full Frame||24.0||6000||4000||4K/60p||25.2||14.5||3333||95|
|9.||Panasonic S1H||Full Frame||24.0||6000||4000||6K/30p||..||..||..||..|
|11.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|12.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|13.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|14.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|15.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|16.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|17.||Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
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, but the A7S III provides a faster frame rate than the fp. It can shoot movie footage at 4K/120p, while the Sigma is limited to 4K/30p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7S III has an electronic viewfinder (9440k dots), which can be very helpful when shooting in bright sunlight. In contrast, the fp relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Sigma fp, the Sony A7S III, and comparable cameras.
|2.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|12.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|13.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
One feature that differentiates the A7S III and the fp is in-body image stabilization (IBIS). The A7S III reduces the risk of handshake-induced blur with all attached lenses, while the fp offers no blur reduction with lenses that themselves do not provide optical image stabilization.The A7S III has an articulated screen that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in taking selfies. In contrast, the fp does not have a selfie-screen.
The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, both cameras under consideration feature an electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).
The Sigma fp has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.
The fp writes its imaging data to SDXC cards, while the A7S III uses CFexpress or SDXC cards. The A7S III features dual card slots, which can be very useful in case a memory card fails. In contrast, the fp only has one slot. Moreover, both cameras support UHS-II cards (Ultra High Speed data transfer of up to 312 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 Sigma fp and Sony Alpha 7S III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|12.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|13.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S III offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the fp does not provide wifi capability.
Both the fp and the A7S III are recent models that are part of the current product line-up. The A7S III replaced the earlier Sony A7S II, while the fp does not have a direct predecessor. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sigma and Sony websites.
So what conclusions can be drawn? Which of the two cameras – the Sigma fp or the Sony A7S III – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Sigma fp:
- More detail: Offers more megapixels (24 vs 12MP) with a 41% higher linear resolution.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- More detailed LCD: Has a higher resolution rear screen (2100k vs 1440k dots).
- Faster burst: Shoots at higher frequency (12 vs 10 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (113x70mm vs 127x97mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 277g or 40 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced category (46 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in July 2019).
Arguments in favor of the Sony Alpha 7S III:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better video: Provides higher movie framerates (4K/120p versus 4K/30p).
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- Easier framing: Has an electronic viewfinder for image composition and settings control.
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Longer lasting: Gets more shots (600 versus 280) out of a single battery charge.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Faster data transfer: Supports a more advanced USB protocol (3.2 vs 3.1).
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- More modern: Was introduced somewhat (1 year) more recently.
If the number of relative strengths (bullet points above) is taken as a guide, the A7S III is the clear winner of the contest (14 : 10 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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 Sigma fp and the Sony A7S III place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera listing whether the two cameras rank among the cream of the crop.
In any case, while the specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the fp or the A7S III. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.
This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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.||Sigma fp||4/5||..||..||4/5||4.5/5||Jul 2019||1,899|
|2.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|3.||Fujifilm X-Pro3||4/5||+||85/100||4/5||..||Oct 2019||1,799|
|4.||Leica M10-P||..||..||..||..||4/5||Aug 2018||7,995|
|5.||Leica SL||4/5||..||84/100||4.5/5||4/5||Oct 2015||7,450|
|6.||Nikon D780||5/5||..||87/100||4.5/5||4.5/5||Jan 2020||2,299|
|7.||Panasonic S5||4.5/5||+ +||..||4.5/5||4.5/5||Sep 2020||1,999|
|8.||Panasonic S1||4.5/5||+ +||88/100||4.5/5||4/5||Feb 2019||2,499|
|9.||Panasonic S1H||..||..||90/100||..||..||May 2019||3,999|
|10.||Panasonic TS7||..||+||..||..||3.5/5||May 2018||449|
|11.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|12.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|13.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|14.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|15.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|16.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|17.||Sony A7||5/5||+ +||80/100||5/5||5/5||Oct 2013||1,699|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, 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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
Other camera comparisons
Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Sigma fp vs Sony A7S 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||Sigma fp||Sony A7S III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Leica L mount lenses||Sony E mount lenses|
|Launch Date||July 2019||July 2020|
|Launch Price||USD 1,899||USD 3,499|
|Sensor Specs||Sigma fp||Sony A7S III|
|Sensor Format||Full Frame Sensor||Full Frame Sensor|
|Sensor Size||35.9 x 23.9 mm||35.6 x 23.8 mm|
|Sensor Area||858.01 mm2||847.28 mm2|
|Sensor Diagonal||43.1 mm||42.8 mm|
|Sensor Resolution||24 Megapixels||12 Megapixels|
|Image Resolution||6000 x 4000 pixels||4240 x 2832 pixels|
|Pixel Pitch||5.98 μm||8.40 μm|
|Pixel Density||2.80 MP/cm2||1.42 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/120p Video|
|ISO Setting||100 - 25,600 ISO||80 - 102,400 ISO|
|ISO Boost||6 - 102,400 ISO||40 - 409,600 ISO|
|DXO Sensor Quality (score)||..||86|
|DXO Color Depth (bits)||..||23.7|
|DXO Dynamic Range (EV)||..||13.9|
|DXO Low Light (ISO)||..||2520|
|Screen Specs||Sigma fp||Sony A7S III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||9440k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2inch||3.0inch|
|LCD Resolution||2100k dots||1440k dots|
|LCD Attachment||Fixed screen||Swivel screen|
|Shooting Specs||Sigma fp||Sony A7S III|
|Focus System||Contrast-detect AF||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||12 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||up to 1/8000s||YES|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||CFexpress or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-II||Dual UHS-II|
|Connectivity Specs||Sigma fp||Sony A7S III|
|USB Connector||USB 3.1||USB 3.2|
|HDMI Port||micro HDMI||full HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Sigma fp||Sony A7S III|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||280 shots per charge||600 shots per charge|
|In-Camera Charging||USB charging||USB charging|
113 x 70 x 45 mm
(4.4 x 2.8 x 1.8 in)
127 x 97 x 81 mm
(5.0 x 3.8 x 3.2 in)
|Camera Weight||422 g (14.9 oz)||699 g (24.7 oz)|
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