Sigma fp vs Sony A5100

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

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

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

Going beyond this snapshot of core features and characteristics, what are the differences between the Sigma fp and the Sony Alpha A5100? 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 and the Sony A5100. 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 Sony A5100 is notably smaller (12 percent) than the Sigma fp. Moreover, the A5100 is markedly lighter (33 percent) than the fp. It is worth mentioning in this context that the fp is splash and dust resistant, 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 fp gets 280 shots out of its Sigma BP-51 battery, while the A5100 can take 400 images on a single charge of its Sony NP-FW50 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 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 A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.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 A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
12.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	1,799	amazon.com
13.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
14.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	449	ebay.com
15.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
16.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	599	ebay.com
17.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	499	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 naturally be influenced heavily by the price. 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 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. 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.

Of the two cameras under consideration, the Sigma fp features a full frame sensor and the Sony A5100 an APS-C sensor. The sensor area in the A5100 is 57 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. 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 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 A5100 are ISO 100 to ISO 25600 (no boost).

In terms of underlying technology, the fp is build around a BSI-CMOS sensor, while the A5100 uses a 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 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 A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
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 A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
12.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
13.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
14.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
15.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
16.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68
17.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
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 also of capturing video footage. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the fp provides a higher video resolution than the A5100. It can shoot video 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 variety of features. The fp and the A5100 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 following table reports on some other key feature differences and similarities of the Sigma fp, the Sony A5100, and comparable 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	optional	n	3.2 / 2100	fixed	Y	1/8000s	12.0/s	n	n
2.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
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 A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
12.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
13.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
14.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
15.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
16.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
17.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
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 fp writes its imaging data to SDXC cards, while the A5100 uses SDXC or Memory Stick PRO Duo 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 Sigma fp and Sony Alpha A5100 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 A5100	-	stereo / mono	-	-	micro	2.0	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 A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
12.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
13.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
15.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
16.		Sony NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-
17.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-

It is notable that the fp has a hotshoe, while the A5100 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

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 fp and A5100 can be found, respectively, in the Sigma fp Manual (free pdf) or the online Sony A5100 Manual.

Review summary

So how do things add up? Is the Sigma fp better than the Sony A5100 or vice versa? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Sigma fp:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Features a larger and more technologically advanced imaging 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 weather sealed to enable shooting in dusty or wet environments.
• 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.

Arguments in favor 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 will fit more readily into a bag.
• Less heavy: Has a lower weight (by 139g or 33 percent) and is thus easier to take along.
• Longer lasting: Gets more shots (400 versus 280) out of a single battery charge.
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• 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 around for much longer (launched in August 2014).

If the count of relative strengths (bullet points above) is taken as a measure, the fp is the clear winner of the match-up (19 : 12 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision 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 A5100 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 A5100. 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 A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.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 A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
12.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	1,799	amazon.com
13.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
14.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	449	ebay.com
15.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
16.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	599	ebay.com
17.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	499	ebay.com
Note: (+ +) 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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparisons of ratings among very different cameras or across long time periods 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 price at
amazon.com
Check A5100 offers at
ebay.com

Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

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

Did you notice an error on this page? If so, please get in touch, so that we can correct the information.