Sigma fp L vs Sony A7 III

The Sigma fp L and the Sony Alpha A7 III are two digital cameras that were revealed to the public, respectively, in March 2021 and February 2018. Both the fp L and the A7 III are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The Sigma has a resolution of 60.2 megapixels, whereas the Sony provides 24 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications

Sigma fp L		Sony A7 III
Mirrorless system camera		Mirrorless system camera
Leica L mount lenses		Sony E mount lenses
60.2 MP – Full Frame sensor		24 MP – Full Frame sensor
4K/30p Video		4K/30p Video
ISO 100-25,600 (6 - 102,400)		ISO 100-51,200 (50 - 204,800)
Viewfinder optional		Electronic viewfinder (2359k dots)
3.2" LCD – 2100k dots		3.0" LCD – 922k dots
Fixed touchscreen		Tilting touchscreen
10 shutter flaps per second		10 shutter flaps per second
Lens stabilization only		In-body stabilization
Weathersealed body		Weathersealed body
240 shots per battery charge		610 shots per battery charge
113 x 70 x 45 mm, 427 g		127 x 96 x 74 mm, 650 g

Check fp L price at
amazon.com
Check A7 III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sigma fp L and the Sony Alpha A7 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.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Sigma fp L and the Sony A7 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 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 A7 III is considerably larger (54 percent) than the Sigma fp L. Moreover, the A7 III is substantially heavier (52 percent) than the fp L. 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.

Concerning battery life, the fp L gets 240 shots out of its Sigma BP-51 battery, while the A7 III can take 610 images on a single charge of its Sony NP-FZ100 power pack. 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.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Sigma fp L	113 mm	70 mm	45 mm	427 g	240	Y	Mar 2021	US$ 2 499	amazon.com
2.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	US$ 1 999	amazon.com
3.		Canon R6	138 mm	98 mm	88 mm	680 g	360	Y	Jul 2020	US$ 2 499	amazon.com
4.		Fujifilm X100V	128 mm	75 mm	53 mm	478 g	420	Y	Feb 2020	US$ 1 399	ebay.com
5.		Leica M11	139 mm	80 mm	39 mm	640 g	700	Y	Jan 2022	US$ 8 999	amazon.com
6.		Nikon D6	160 mm	163 mm	92 mm	1270 g	3580	Y	Feb 2020	US$ 6 499	amazon.com
7.		Nikon D780	144 mm	116 mm	76 mm	840 g	2260	Y	Jan 2020	US$ 2 299	amazon.com
8.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	US$ 1 999	ebay.com
9.		Sigma fp	113 mm	70 mm	45 mm	422 g	280	Y	Jul 2019	US$ 1 899	amazon.com
10.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	US$ 1 999	ebay.com
11.		Sony A7C R	124 mm	71 mm	63 mm	520 g	520	Y	Aug 2023	US$ 2 999	amazon.com
12.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	US$ 2 299	ebay.com
13.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	US$ 3 199	ebay.com
14.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	US$ 3 499	ebay.com
15.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	US$ 2 499	ebay.com
16.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	US$ 4 499	ebay.com
17.		Sony RX1R III	113 mm	68 mm	88 mm	498 g	300	Y	Jul 2025	US$ 5 099	amazon.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

Any camera decision will obviously take relative prices into account. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The A7 III was launched at a somewhat lower price (by 20 percent) than the fp L, which makes it more attractive for photographers on a tight budget. 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.

Sensor comparison

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. 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 associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. The sensor area in the A7 III is 2 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.

With 60.2MP, the fp L offers a higher resolution than the A7 III (24MP), but the fp L has smaller individual pixels (pixel pitch of 3.79μm versus 5.94μm for the A7 III). However, the fp L is a much more recent model (by 3 years) than the A7 III, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels.

The resolution advantage of the Sigma fp L implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the fp L for good quality output (200 dots per inch) amounts to 47.6 x 31.6 inches or 120.9 x 80.4 cm, for very good quality (250 dpi) 38.1 x 25.3 inches or 96.7 x 64.3 cm, and for excellent quality (300 dpi) 31.7 x 21.1 inches or 80.6 x 53.6 cm. The corresponding values for the Sony A7 III 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 A7 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Sigma fp L 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 A7 III are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.

Technology-wise, both cameras are equipped with BSI-CMOS (Backside Illuminated Complementary Metal–Oxide–Semiconductor) sensors. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Sigma fp L	Full Frame	60.2	9520	6328	4K/30p	25.3	14.4	3001	96
2.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
3.		Canon R6	Full Frame	20.0	5472	3648	4k/60p	24.2	14.3	3394	90
4.		Fujifilm X100V	APS-C	26.0	6240	4160	4K/30p	24.2	13.6	1996	84
5.		Leica M11	Full Frame	60.3	9528	6328	none	26.3	14.8	3376	100
6.		Nikon D6	Full Frame	20.7	5568	3712	4K/30p	25.3	14.3	2886	95
7.		Nikon D780	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	2877	95
8.		Nikon Z6	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	3299	95
9.		Sigma fp	Full Frame	24.0	6000	4000	4K/30p	25.2	14.2	2829	94
10.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
11.		Sony A7C R	Full Frame	60.2	9504	6336	4K/60p	25.4	14.7	3227	96
12.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
13.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
14.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
15.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
16.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
17.		Sony RX1R III	Full Frame	60.2	9504	6336	4K/30p	25.4	14.9	3417	97
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. 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).

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A7 III has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the fp L relies on live view and the rear LCD for framing. That said, the fp L can be equipped with an optional viewfinder – the EVF-11. The table below summarizes some of the other core capabilities of the Sigma fp L and Sony A7 III in connection with corresponding information for a sample of similar cameras.

Core Features

		Camera Model	Viewfinder (Type or 000 dots)	Control Panel (yes/no)	LCD Specifications (inch/000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Max Shutter Speed *	Max Shutter Flaps *	Built-in Flash (yes/no)	Built-in Image Stab
1.		Sigma fp L	optional	n	3.2 / 2100	fixed	Y	1/8000s	10.0/s	n	n
2.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
3.		Canon R6	3690	n	3.0 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
4.		Fujifilm X100V	3690	n	3.0 / 1620	tilting	Y	1/4000s	11.0/s	n	n
5.		Leica M11	optical	n	3.0 / 2333	fixed	Y	1/4000s	4.5/s	n	n
6.		Nikon D6	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
7.		Nikon D780	optical	Y	3.2 / 2359	tilting	Y	1/8000s	12.0/s	n	n
8.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
9.		Sigma fp	optional	n	3.2 / 2100	fixed	Y	1/8000s	12.0/s	n	n
10.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
11.		Sony A7C R	2360	n	3.0 / 1037	swivel	Y	1/4000s	8.0/s	n	Y
12.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
13.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
14.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
15.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
16.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
17.		Sony RX1R III	2360	n	3.0 / 2360	fixed	Y	1/4000s	5.0/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the A7 III and the fp L is in-body image stabilization (IBIS). The A7 III reduces the risk of handshake-induced blur with all attached lenses, while the fp L 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 L and the Sony A7 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 L writes its imaging data to SDXC cards, while the A7 III uses SDXC or Memory Stick PRO Duo cards. The A7 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the fp L only has one slot. Both the fp L and the A7 III support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 MB/s (the second slot of the A7 III only offers slower UHS-I transfer rates, though).

Connectivity comparison

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 L and Sony Alpha A7 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Sigma fp L	Y	stereo / mono	Y	Y	micro	3.2	Y	-	-
2.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
3.		Canon R6	Y	mono / mono	Y	Y	micro	3.2	Y	-	Y
4.		Fujifilm X100V	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
5.		Leica M11	Y	- / -	-	-	-	3.2	Y	-	Y
6.		Nikon D6	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
7.		Nikon D780	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
8.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
9.		Sigma fp	Y	stereo / mono	Y	-	micro	3.1	-	-	-
10.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
11.		Sony A7C R	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
12.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
14.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
15.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
17.		Sony RX1R III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y

Both the fp L and the A7 III are recent models that are part of the current product line-up. The A7 III replaced the earlier Sony A7 II, while the fp L does not have a direct predecessor. Further information on the features and operation of the fp L and A7 III can be found, respectively, in the Sigma fp L Manual (free pdf) or the online Sony A7 III Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Sigma fp L or the Sony A7 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.

Advantages of the Sigma fp L:

• More detail: Offers more megapixels (60.2 vs 24MP) with a 59% higher linear resolution.
• 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 922k dots).
• More compact: Is smaller (113x70mm vs 127x96mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 223g or 34 percent) and hence easier to carry around.
• Faster data transfer: Supports a more advanced USB protocol (3.2 vs 3.1).
• More modern: Reflects 3 years of technical progress since the A7 III launch.

Reasons to prefer the Sony Alpha A7 III:

• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• 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 (610 versus 240) out of a single battery charge.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• 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 affordable: Was released into a lower priced segment (20 percent cheaper at launch).
• More heavily discounted: Has been around for much longer (launched in February 2018).

If the count of individual advantages (bullet points above) is taken as a guide, the A7 III emerges as the winner of the match-up (10 : 7 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 L and the Sony A7 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 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 fp L or the A7 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.

Expert reviews

This is why expert reviews are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], 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.

Expert Camera Reviews

		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price	Street Price
1.		Sigma fp L	4/5	..	4/5	..	4/5	4/5	Mar 2021	US$ 2 499	amazon.com
2.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	US$ 1 999	amazon.com
3.		Canon R6	5/5	+ +	4/5	90/100	4.5/5	5/5	Jul 2020	US$ 2 499	amazon.com
4.		Fujifilm X100V	5/5	+ +	4.5/5	86/100	5/5	4.5/5	Feb 2020	US$ 1 399	ebay.com
5.		Leica M11	4.5/5	..	4.5/5	..	4.5/5	4.5/5	Jan 2022	US$ 8 999	amazon.com
6.		Nikon D6	..	..	4/5	..	4.5/5	4.5/5	Feb 2020	US$ 6 499	amazon.com
7.		Nikon D780	5/5	..	5/5	87/100	4.5/5	4.5/5	Jan 2020	US$ 2 299	amazon.com
8.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	US$ 1 999	ebay.com
9.		Sigma fp	4/5	..	4/5	..	4/5	4.5/5	Jul 2019	US$ 1 899	amazon.com
10.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	US$ 1 999	ebay.com
11.		Sony A7C R	4/5	..	4/5	88/100	..	4/5	Aug 2023	US$ 2 999	amazon.com
12.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	US$ 2 299	ebay.com
13.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	US$ 3 199	ebay.com
14.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	US$ 3 499	ebay.com
15.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	US$ 2 499	ebay.com
16.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	US$ 4 499	ebay.com
17.		Sony RX1R III	..	..	..	..	..	..	Jul 2025	US$ 5 099	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated 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 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.

Check fp L price at
amazon.com
Check A7 III price at
amazon.com

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. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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Check fp L price at
amazon.com
Check A7 III price at
amazon.com

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