Sigma fp vs Sony A7 IV

The Sigma fp and the Sony Alpha A7 IV are two digital cameras that were announced, respectively, in July 2019 and October 2021. Both the fp and the A7 IV 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 32.7 MP.

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

Headline Specifications

Sigma fp		Sony A7 IV
Mirrorless system camera		Mirrorless system camera
Leica L mount lenses		Sony E mount lenses
24 MP – Full Frame sensor		32.7 MP – Full Frame sensor
4K/30p Video		4K/60p Video
ISO 100-25,600 (6 - 102,400)		ISO 100-51,200 (50 - 204,800)
Viewfinder optional		Electronic viewfinder (3686k dots)
3.2" LCD – 2100k dots		3.0" LCD – 1037k dots
Fixed touchscreen		Swivel touchscreen
12 shutter flaps per second		10 shutter flaps per second
Lens stabilization only		In-body stabilization
Weathersealed body		Weathersealed body
280 shots per battery charge		580 shots per battery charge
113 x 70 x 45 mm, 422 g		131 x 96 x 80 mm, 659 g

Check fp price at
amazon.com
Check A7 IV price at
amazon.com

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

An illustration of the physical size and weight of the Sigma fp and the Sony A7 IV is provided in the side-by-side display below. 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 A7 IV is considerably larger (59 percent) than the Sigma fp. Moreover, the A7 IV is substantially heavier (56 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.

Concerning battery life, the fp gets 280 shots out of its Sigma BP-51 battery, while the A7 IV can take 580 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 (USD)	Street Price
1.		Sigma fp	113 mm	70 mm	45 mm	422 g	280	Y	Jul 2019	1,899	amazon.com
2.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	2,499	amazon.com
3.		Fujifilm X-Pro3	141 mm	83 mm	46 mm	497 g	440	Y	Oct 2019	1,799	amazon.com
4.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
5.		Nikon D780	144 mm	116 mm	76 mm	840 g	2260	Y	Jan 2020	2,299	amazon.com
6.		Panasonic S1	149 mm	110 mm	97 mm	1017 g	400	Y	Feb 2019	2,499	amazon.com
7.		Panasonic S1H	151 mm	114 mm	110 mm	1052 g	400	Y	May 2019	3,999	amazon.com
8.		Panasonic S5	133 mm	98 mm	82 mm	714 g	440	Y	Sep 2020	1,999	amazon.com
9.		Panasonic TS7	117 mm	76 mm	37 mm	319 g	300	Y	May 2018	449	ebay.com
10.		Sigma fp L	113 mm	70 mm	45 mm	427 g	240	Y	Mar 2021	2,499	amazon.com
11.		Sony A1	129 mm	97 mm	81 mm	737 g	530	Y	Jan 2021	6,499	amazon.com
12.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
13.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
14.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	1,799	amazon.com
15.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	3,199	amazon.com
16.		Sony A7R V	131 mm	97 mm	82 mm	723 g	530	Y	Oct 2022	3,899	amazon.com
17.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	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 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 somewhat lower price (by 24 percent) than the A7 IV, 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 generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have 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 associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature a full frame sensor and have a format factor (sometimes also referred to as "crop factor") of 1.0. Within the spectrum of camera sensors, this places the review cameras among the large-sensor cameras that aim for top notch image quality. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

While the two cameras under review share the same sensor size, the A7 IV offers a higher resolution of 32.7 megapixels, compared with 24 MP of the fp. This megapixels advantage translates into a 17 percent gain in linear resolution. On the other hand, these sensor specs imply that the A7 IV has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 5.12μm versus 5.98μm for the fp). However, it should be noted that the A7 IV is much more recent (by 2 years and 3 months) than the fp, and its sensor will have benefitted from technological advances during this time that compensate for the smaller pixel size. 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 A7 IV implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7 IV for good quality output (200 dots per inch) amounts to 35 x 23.4 inches or 89 x 59.3 cm, for very good quality (250 dpi) 28 x 18.7 inches or 71.2 x 47.5 cm, and for excellent quality (300 dpi) 23.4 x 15.6 inches or 59.3 x 39.6 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 A7 IV has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

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 A7 IV 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.

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 adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

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	Full Frame	24.0	6000	4000	4K/30p	25.2	14.2	2829	94
2.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
3.		Fujifilm X-Pro3	APS-C	26.0	6240	4160	4K/30p	24.1	13.6	1968	84
4.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
5.		Nikon D780	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	2877	95
6.		Panasonic S1	Full Frame	24.0	6000	4000	4K/60p	25.2	14.5	3333	95
7.		Panasonic S1H	Full Frame	24.0	6000	4000	6K/30p	25.2	14.2	2805	94
8.		Panasonic S5	Full Frame	24.0	6000	4000	4K/60p	25.1	14.5	2697	94
9.		Panasonic TS7	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1028	51
10.		Sigma fp L	Full Frame	60.2	9520	6328	4K/30p	25.3	14.4	3001	96
11.		Sony A1	Full Frame	49.8	8640	5760	8k/30p	25.9	14.5	3163	98
12.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
13.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
14.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
15.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
16.		Sony A7R V	Full Frame	60.2	9504	6336	8k/24p	26.5	14.8	3187	100
17.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7 IV provides a faster frame rate than the fp. It can shoot movie footage at 4K/60p, while the Sigma is limited to 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7 IV 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. That said, the fp can be equipped with an optional viewfinder – the EVF-11. The adjacent table lists some of the other core features of the Sigma fp and Sony A7 IV along with similar information for a selection of comparators.

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	optional	n	3.2 / 2100	fixed	Y	1/8000s	12.0/s	n	n
2.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
3.		Fujifilm X-Pro3	3690	n	3.0 / 1620	tilting	Y	1/8000s	8.0/s	n	n
4.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
5.		Nikon D780	optical	Y	3.2 / 2359	tilting	Y	1/8000s	12.0/s	n	n
6.		Panasonic S1	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
7.		Panasonic S1H	5760	Y	3.2 / 2330	swivel	Y	1/8000s	9.0/s	n	Y
8.		Panasonic S5	2360	n	3.0 / 1840	swivel	Y	1/8000s	7.0/s	n	Y
9.		Panasonic TS7	1170	n	3.0 / 1040	fixed	n	1/1300s	10.0/s	Y	Y
10.		Sigma fp L	optional	n	3.2 / 2100	fixed	Y	1/8000s	10.0/s	n	n
11.		Sony A1	9437	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
12.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
13.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
14.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
15.		Sony A7R IIIA	3686	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
16.		Sony A7R V	9440	n	3.2 / 2100	full-flex	Y	1/8000s	10.0/s	n	Y
17.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the A7 IV and the fp is in-body image stabilization (IBIS). The A7 IV 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 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 A7 IV uses CFexpress (type A) or SDXC cards. The A7 IV 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).

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 and Sony Alpha A7 IV 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	Y	stereo / mono	Y	-	micro	3.1	-	-	-
2.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
3.		Fujifilm X-Pro3	Y	stereo / mono	Y	-	-	3.1	Y	-	Y
4.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
5.		Nikon D780	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
6.		Panasonic S1	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
7.		Panasonic S1H	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
8.		Panasonic S5	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
9.		Panasonic TS7	-	stereo / mono	-	-	micro	2.0	Y	-	-
10.		Sigma fp L	Y	stereo / mono	Y	Y	micro	3.2	Y	-	-
11.		Sony A1	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
12.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
14.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
15.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
16.		Sony A7R V	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
17.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y

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

Review summary

So what conclusions can be drawn? Is the Sigma fp better than the Sony A7 IV or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of 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 1037k 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 131x96mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 237g or 36 percent) and hence easier to carry around.
• More affordable: Was introduced into a lower priced segment (24 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in July 2019).

Arguments in favor of the Sony Alpha A7 IV:

• More detail: Has more megapixels (32.7 vs 24MP), which boosts linear resolution by 17%.
• Better video: Provides higher movie framerates (4K/60p versus 4K/30p).
• 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 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 (580 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: Reflects 2 years and 3 months of technical progress since the fp launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A7 IV is the clear winner of the contest (15 : 8 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 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 A7 IV 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 incomplete and does no justice, for example, to the way the fp or the A7 IV perform in practice. 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 hands-on reviews by experts 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 (USD)	Street Price
1.		Sigma fp	4/5	..	4/5	..	4/5	4.5/5	Jul 2019	1,899	amazon.com
2.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	2,499	amazon.com
3.		Fujifilm X-Pro3	4/5	+	4/5	85/100	4/5	..	Oct 2019	1,799	amazon.com
4.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
5.		Nikon D780	5/5	..	5/5	87/100	4.5/5	4.5/5	Jan 2020	2,299	amazon.com
6.		Panasonic S1	4.5/5	+ +	4.5/5	88/100	4.5/5	4/5	Feb 2019	2,499	amazon.com
7.		Panasonic S1H	..	..	4/5	90/100	..	..	May 2019	3,999	amazon.com
8.		Panasonic S5	4.5/5	+ +	4.5/5	88/100	4.5/5	4.5/5	Sep 2020	1,999	amazon.com
9.		Panasonic TS7	..	+	..	..	..	3.5/5	May 2018	449	ebay.com
10.		Sigma fp L	4/5	..	4/5	..	4/5	4/5	Mar 2021	2,499	amazon.com
11.		Sony A1	5/5	o	4.5/5	93/100	4.5/5	5/5	Jan 2021	6,499	amazon.com
12.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
13.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
14.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	1,799	amazon.com
15.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	3,199	amazon.com
16.		Sony A7R V	5/5	+ +	4.5/5	92/100	..	..	Oct 2022	3,899	amazon.com
17.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. 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. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check fp price at
amazon.com
Check A7 IV price at
amazon.com

Other camera comparisons

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