Sony A5100 vs Sigma fp

The Sony Alpha A5100 and the Sigma fp are two digital cameras that were officially introduced, respectively, in August 2014 and July 2019. Both the A5100 and the fp are mirrorless interchangeable lens cameras that are based on an APS-C (A5100) and a full frame (fp) sensor. Both cameras offer a resolution of 24 megapixels.

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

Headline Specifications

Sony A5100		Sigma fp
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Leica L mount lenses
24 MP – APS-C sensor		24 MP – Full Frame sensor
1080/60p Video		4K/30p Video
ISO 100-25,600		ISO 100-25,600 (6 - 102,400)
No viewfinder, LCD framing		Viewfinder optional
3.0" LCD – 922k dots		3.2" LCD – 2100k dots
Tilting touchscreen		Fixed touchscreen
6 shutter flaps per second		12 shutter flaps per second
not weather sealed		Weathersealed body
400 shots per battery charge		280 shots per battery charge
110 x 63 x 36 mm, 283 g		113 x 70 x 45 mm, 422 g

Check A5100 offers at
ebay.com
Check fp price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A5100 and the Sigma fp? 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 Sony A5100 and the Sigma fp 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.

The A5100 can be obtained in two different colors (black, white), while the fp 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 Sigma fp is notably larger (14 percent) than the Sony A5100. Moreover, the fp is substantially heavier (49 percent) than the A5100. It is noteworthy in this context that the fp is splash and dust-proof, while the A5100 does not feature any corresponding weather-sealing.

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 A5100 gets 400 shots out of its Sony NP-FW50 battery, while the fp can take 280 images on a single charge of its Sigma BP-51 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
2.		Sigma fp	113 mm	70 mm	45 mm	422 g	280	Y	Jul 2019	1,899	amazon.com
3.		Fujifilm X-Pro3	141 mm	83 mm	46 mm	497 g	440	Y	Oct 2019	1,799	amazon.com
4.		Nikon D780	144 mm	116 mm	76 mm	840 g	2260	Y	Jan 2020	2,299	amazon.com
5.		Panasonic S1	149 mm	110 mm	97 mm	1017 g	400	Y	Feb 2019	2,499	amazon.com
6.		Panasonic S1H	151 mm	114 mm	110 mm	1052 g	400	Y	May 2019	3,999	amazon.com
7.		Panasonic S5	133 mm	98 mm	82 mm	714 g	440	Y	Sep 2020	1,999	amazon.com
8.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
9.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	449	ebay.com
10.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
11.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	599	ebay.com
12.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	499	ebay.com
13.		Sony NEX-5T	111 mm	59 mm	39 mm	276 g	330	n	Aug 2013	699	ebay.com
14.		Sony NEX-F3	117 mm	67 mm	42 mm	314 g	470	n	May 2012	599	ebay.com
15.		Sony RX100	102 mm	58 mm	36 mm	240 g	330	n	Jun 2012	649	ebay.com
16.		Sony RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	749	ebay.com
17.		Sony RX100 IV	102 mm	58 mm	41 mm	298 g	280	n	Jun 2015	999	ebay.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 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 A5100 was launched at a markedly lower price (by 71 percent) than the fp, 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.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony A5100 features an APS-C sensor and the Sigma fp a full frame sensor. The sensor area in the fp is 134 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Even though the fp has a larger sensor, both cameras offer the same resolution of 24 megapixels. This implies that the fp has a lower pixel density and larger individual pixels (with a pixel pitch of 5.98μm versus 3.91μm for the A5100), which gives it a potential advantage in terms of light gathering capacity. In addition, the fp is much more recent (by 4 years and 10 months) than the A5100, and its sensor will have benefitted from technological advances during this time. 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 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 Sigma fp are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 6-102400.

In terms of underlying technology, the A5100 is build around a CMOS sensor, while the fp uses a BSI-CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

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.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
2.		Sigma fp	Full Frame	24.0	6000	4000	4K/30p	25.2	14.2	2829	94
3.		Fujifilm X-Pro3	APS-C	26.0	6240	4160	4K/30p	24.1	13.6	1968	84
4.		Nikon D780	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	2877	95
5.		Panasonic S1	Full Frame	24.0	6000	4000	4K/60p	25.2	14.5	3333	95
6.		Panasonic S1H	Full Frame	24.0	6000	4000	6K/30p	25.2	14.2	2805	94
7.		Panasonic S5	Full Frame	24.0	6000	4000	4K/60p	25.1	14.5	2697	94
8.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
9.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
10.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
11.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68
12.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
13.		Sony NEX-5T	APS-C	16.0	4912	3264	1080/60p	23.6	13.0	1015	78
14.		Sony NEX-F3	APS-C	16.0	4912	3264	1080/60i	22.7	12.3	1114	73
15.		Sony RX100	1-inch	20.0	5472	3648	1080/60p	22.6	12.4	390	66
16.		Sony RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
17.		Sony RX100 IV	1-inch	20.0	5472	3648	4K/30p	22.8	12.6	591	70
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 fp provides a better video resolution than the A5100. It can shoot movie footage at 4K/30p, while the Sony is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The A5100 and the fp are similar in the sense that neither of the two has a viewfinder. The images are, thus, framed using live view on the rear LCD. That said, the fp can be equipped with an optional viewfinder – the EVF-11. The table below summarizes some of the other core capabilities of the Sony A5100 and Sigma fp 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.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
2.		Sigma fp	optional	n	3.2 / 2100	fixed	Y	1/8000s	12.0/s	n	n
3.		Fujifilm X-Pro3	3690	n	3.0 / 1620	tilting	Y	1/8000s	8.0/s	n	n
4.		Nikon D780	optical	Y	3.2 / 2359	tilting	Y	1/8000s	12.0/s	n	n
5.		Panasonic S1	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
6.		Panasonic S1H	5760	Y	3.2 / 2330	swivel	Y	1/8000s	9.0/s	n	Y
7.		Panasonic S5	2360	n	3.0 / 1840	swivel	Y	1/8000s	7.0/s	n	Y
8.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
9.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
10.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
11.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
12.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
13.		Sony NEX-5T	optional	n	3.0 / 922	tilting	Y	1/4000s	10.0/s	n	n
14.		Sony NEX-F3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	Y	n
15.		Sony RX100	none	n	3.0 / 1229	fixed	n	1/2000s	10.0/s	Y	Y
16.		Sony RX100 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
17.		Sony RX100 IV	2359	n	3.0 / 1228	tilting	n	1/2000s	16.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The A5100 has one, while the fp does not. While the built-in flash of the A5100 is not very powerful, it can at times be useful as a fill-in light.

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, the fp is one of those camera that have an additional 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 A5100 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the fp uses SDXC cards. The fp supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the A5100 can use UHS-I cards (up to 104 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 Sony Alpha A5100 and Sigma fp 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.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
2.		Sigma fp	Y	stereo / mono	Y	-	micro	3.1	-	-	-
3.		Fujifilm X-Pro3	Y	stereo / mono	Y	-	-	3.1	Y	-	Y
4.		Nikon D780	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
5.		Panasonic S1	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
6.		Panasonic S1H	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
7.		Panasonic S5	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
8.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
9.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
10.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
11.		Sony NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-
12.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-
13.		Sony NEX-5T	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
14.		Sony NEX-F3	Y	stereo / mono	-	-	mini	2.0	-	-	-
15.		Sony RX100	-	stereo / mono	-	-	micro	2.0	-	-	-
16.		Sony RX100 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
17.		Sony RX100 IV	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the A5100 offers wifi support, while the fp does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

The fp is a recent model that features in the current product line-up of Sigma. In contrast, the A5100 has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the A5100 from Sony. Further information on the features and operation of the A5100 and fp can be found, respectively, in the Sony A5100 Manual (free pdf) or the online Sigma fp Manual.

Review summary

So what conclusions can be drawn? Is the Sony A5100 better than the Sigma fp or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Sony Alpha A5100:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• More compact: Is smaller (110x63mm vs 113x70mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 139g or 33 percent) and hence easier to carry around.
• Longer lasting: Can take more shots (400 versus 280) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• 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.
• More affordable: Was introduced into a lower priced category (71 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in August 2014).

Reasons to prefer the Sigma fp:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Is equipped with a larger and more technologically advanced sensor.
• Richer colors: The sensor size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• More framing options: Can be equipped with a hotshoe-mounted accessory-viewfinder.
• 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).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 6 flaps/sec) to capture the decisive moment.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More modern: Reflects 4 years and 10 months of technical progress since the A5100 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the fp is the clear winner of the contest (19 : 12 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 Sony A5100 and the Sigma fp 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 A5100 or the fp 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.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
2.		Sigma fp	4/5	..	4/5	..	4/5	4.5/5	Jul 2019	1,899	amazon.com
3.		Fujifilm X-Pro3	4/5	+	4/5	85/100	4/5	..	Oct 2019	1,799	amazon.com
4.		Nikon D780	5/5	..	5/5	87/100	4.5/5	4.5/5	Jan 2020	2,299	amazon.com
5.		Panasonic S1	4.5/5	+ +	4.5/5	88/100	4.5/5	4/5	Feb 2019	2,499	amazon.com
6.		Panasonic S1H	..	..	4/5	90/100	..	..	May 2019	3,999	amazon.com
7.		Panasonic S5	4.5/5	+ +	4.5/5	88/100	4.5/5	4.5/5	Sep 2020	1,999	amazon.com
8.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
9.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	449	ebay.com
10.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
11.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	599	ebay.com
12.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	499	ebay.com
13.		Sony NEX-5T	..	..	..	..	4.5/5	4.5/5	Aug 2013	699	ebay.com
14.		Sony NEX-F3	4/5	..	..	74/100	4.5/5	4.5/5	May 2012	599	ebay.com
15.		Sony RX100	5/5	+ +	..	78/100	4/5	5/5	Jun 2012	649	ebay.com
16.		Sony RX100 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	749	ebay.com
17.		Sony RX100 IV	4.5/5	+ +	..	85/100	4/5	4.5/5	Jun 2015	999	ebay.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.

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Other camera comparisons

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