Sigma fp vs Sony A7R III
The Sigma fp and the Sony Alpha A7R III are two digital cameras that were officially introduced, respectively, in July 2019 and October 2017. Both the fp and the A7R 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 42.2 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 A7R 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 Sigma fp and the Sony A7R III is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All width, height and depth measures 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 A7R III is considerably larger (54 percent) than the Sigma fp. Moreover, the A7R III is substantially heavier (54 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 table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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 A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|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.||Nikon Z7||134 mm||101 mm||67 mm||675 g||330||Y||Aug 2018||3,399|
|8.||Panasonic S5||133 mm||98 mm||82 mm||714 g||440||Y||Sep 2020||1,999|
|9.||Panasonic S1||149 mm||110 mm||97 mm||1017 g||400||Y||Feb 2019||2,499|
|10.||Panasonic S1H||151 mm||114 mm||110 mm||1052 g||400||Y||May 2019||3,999|
|11.||Panasonic TS7||117 mm||76 mm||37 mm||319 g||300||Y||May 2018||449|
|12.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|13.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|14.||Sony A99 II||143 mm||104 mm||76 mm||849 g||490||Y||Sep 2016||3,199|
|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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The fp was launched at a markedly lower price (by 41 percent) than the A7R III, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its 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. 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.
In terms of underlying technology, both cameras are build around BSI-CMOS sensors.
With 42.2MP, the A7R III offers a higher resolution than the fp (24MP), but the A7R III has smaller individual pixels (pixel pitch of 4.52μm versus 5.98μm for the fp). It is noteworthy in this context that the fp is a somewhat more recent model (by 1 year and 8 months) than the A7R III, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.
The resolution advantage of the Sony A7R III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R III for good quality output (200 dots per inch) amounts to 39.8 x 26.5 inches or 101 x 67.4 cm, for very good quality (250 dpi) 31.8 x 21.2 inches or 80.8 x 53.9 cm, and for excellent quality (300 dpi) 26.5 x 17.7 inches or 67.3 x 44.9 cm. The corresponding values for the Sigma fp are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.
The A7R III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the fp, the A7R III has the capacity to capture high quality composite images by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).
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 A7R III are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.
For many cameras, data on sensor performance has been reported by DXO Mark. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. 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 A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|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.||Nikon Z7||Full Frame||45.4||8256||5504||4K/30p||26.3||14.6||2668||99|
|8.||Panasonic S5||Full Frame||24.0||6000||4000||4K/60p||..||..||..||..|
|9.||Panasonic S1||Full Frame||24.0||6000||4000||4K/60p||25.2||14.5||3333||95|
|10.||Panasonic S1H||Full Frame||24.0||6000||4000||6K/30p||..||..||..||..|
|12.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|13.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|14.||Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||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 are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (4K/30p).
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7R III has an electronic viewfinder (3686k 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 table below summarizes some of the other core capabilities of the Sigma fp and Sony A7R III in connection with corresponding information for a sample of similar cameras.
|2.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||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 A7R III and the fp is in-body image stabilization (IBIS). The A7R 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 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 and the Sony A7R III both have 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 A7R III uses SDXC or Memory Stick PRO Duo cards. The A7R III features dual card slots, which can be very useful in case a memory card fails. In contrast, the fp only has one slot. Both the fp and the A7R III support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 MB/s (the second slot of the A7R III only offers slower UHS-I transfer rates, though).
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 A7R III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||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 A7R 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.
Studio photographers will appreciate that the Sony A7R III (unlike the fp) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The fp is a recent model that features in the current product line-up of Sigma. In contrast, the A7R III has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A7R III was succeeded by the Sony A7R IV. 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 is the bottom line? Which of the two cameras – the Sigma fp or the Sony A7R III – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Sigma fp:
- 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.
- More compact: Is smaller (113x70mm vs 127x96mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 228g or 35 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced category (41 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 1 year and 8 months after the A7R III).
Advantages of the Sony Alpha A7R III:
- More detail: Has more megapixels (42.2 vs 24MP), which boosts linear resolution by 33%.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 tilting screen for odd-angle shots in landscape orientation.
- Longer lasting: Gets more shots (650 versus 280) out of a single battery charge.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- More heavily discounted: Has been on the market for longer (launched in October 2017).
If the count of relative strengths (bullet points above) is taken as a measure, the A7R III is the clear winner of the contest (14 : 7 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Sigma fp and the Sony A7R 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the fp and the A7R III in practical situations. 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 A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|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.||Nikon Z7||5/5||+||89/100||4.5/5||5/5||Aug 2018||3,399|
|8.||Panasonic S5||4.5/5||+ +||..||4.5/5||4.5/5||Sep 2020||1,999|
|9.||Panasonic S1||4.5/5||+ +||88/100||4.5/5||4/5||Feb 2019||2,499|
|10.||Panasonic S1H||..||..||90/100||..||..||May 2019||3,999|
|11.||Panasonic TS7||..||+||..||..||3.5/5||May 2018||449|
|12.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|13.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|14.||Sony A99 II||..||..||85/100||4.5/5||4.5/5||Sep 2016||3,199|
|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.|
The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, please note that some of the review sites have changed their methodology and reporting over time.
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 your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Sigma fp vs Sony A7R 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 A7R III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Leica L mount lenses||Sony E mount lenses|
|Launch Date||July 2019||October 2017|
|Launch Price||USD 1,899||USD 3,199|
|Sensor Specs||Sigma fp||Sony A7R III|
|Sensor Format||Full Frame Sensor||Full Frame Sensor|
|Sensor Size||35.9 x 23.9 mm||35.9 x 24.0 mm|
|Sensor Area||858.01 mm2||861.6 mm2|
|Sensor Diagonal||43.1 mm||43.2 mm|
|Sensor Resolution||24 Megapixels||42.2 Megapixels|
|Image Resolution||6000 x 4000 pixels||7952 x 5304 pixels|
|Pixel Pitch||5.98 μm||4.52 μm|
|Pixel Density||2.80 MP/cm2||4.90 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||4K/30p Video||4K/30p Video|
|ISO Setting||100 - 25,600 ISO||100 - 32,000 ISO|
|ISO Boost||6 - 102,400 ISO||50 - 102,400 ISO|
|DXO Sensor Quality (score)||..||100|
|DXO Color Depth (bits)||..||26.0|
|DXO Dynamic Range (EV)||..||14.7|
|DXO Low Light (ISO)||..||3523|
|Screen Specs||Sigma fp||Sony A7R III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2inch||3.0inch|
|LCD Resolution||2100k dots||1440k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Shooting Specs||Sigma fp||Sony A7R III|
|Focus System||Contrast-detect AF||On-Sensor Phase-detect|
|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||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-II||Single UHS-II|
|Connectivity Specs||Sigma fp||Sony A7R III|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 3.1||USB 3.1|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Sigma fp||Sony A7R III|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||280 shots per charge||650 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 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
|Camera Weight||422 g (14.9 oz)||650 g (22.9 oz)|
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