Fujifilm X100 vs Sony A5100

The Fujifilm FinePix X100 and the Sony Alpha A5100 are two digital cameras that were announced, respectively, in September 2010 and August 2014. The X100 is a fixed lens compact, while the A5100 is a mirrorless interchangeable lens camera. Both cameras are equipped with an APS-C sensor. The Fujifilm has a resolution of 12.2 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

Fujifilm X100		Sony A5100
Fixed lens compact camera		Mirrorless system camera
35mm f/2.0		Sony E mount lenses
12.2 MP – APS-C sensor		24 MP – APS-C sensor
720/30p Video		1080/60p Video
ISO 200-6,400 (100 - 12,800)		ISO 100-25,600
Electronic viewfinder (1440k dots)		No viewfinder, LCD framing
2.8" LCD – 460k dots		3.0" LCD – 922k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
5 shutter flaps per second		6 shutter flaps per second
300 shots per battery charge		400 shots per battery charge
126 x 75 x 54 mm, 445 g		110 x 63 x 36 mm, 283 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Fujifilm FinePix X100 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

An illustration of the physical size and weight of the Fujifilm X100 and the Sony A5100 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 size dimensions are rounded to the nearest millimeter.

The A5100 can be obtained in two different colors (black, white), while the X100 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 (27 percent) than the Fujifilm X100. In this context, it is worth noting that neither the X100 nor the A5100 are weather-sealed.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the X100 has a lens built in, whereas the A5100 is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup. You can compare the optics available for the A5100 and their specifications in the Sony E-Mount Lens Catalog.

Concerning battery life, the X100 gets 300 shots out of its Fujifilm NP-95 battery, while the A5100 can take 400 images on a single charge of its Sony NP-FW50 power pack. The power pack in the A5100 can be charged via the USB port, which can be very convenient when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Fujifilm X100	126 mm	75 mm	54 mm	445 g	300	n	Sep 2010	1,199	ebay.com
2.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
3.		Canon G1 X	117 mm	81 mm	65 mm	534 g	250	n	Jan 2012	799	ebay.com
4.		Fujifilm X30	119 mm	72 mm	60 mm	423 g	470	n	Aug 2014	599	ebay.com
5.		Fujifilm X100S	127 mm	74 mm	54 mm	445 g	330	n	Jan 2013	1,299	ebay.com
6.		Fujifilm X100T	127 mm	74 mm	52 mm	440 g	330	n	Sep 2014	1,299	ebay.com
7.		Fujifilm X100F	127 mm	75 mm	52 mm	469 g	390	n	Jan 2017	1,299	ebay.com
8.		Leica D-LUX Typ 109	118 mm	66 mm	55 mm	405 g	300	n	Sep 2014	1,195	ebay.com
9.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	599	ebay.com
10.		Nikon D3100	124 mm	96 mm	75 mm	505 g	550	n	Aug 2010	599	ebay.com
11.		Panasonic LX100	115 mm	66 mm	55 mm	393 g	300	n	Sep 2014	899	ebay.com
12.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
13.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	449	ebay.com
14.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
15.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	599	ebay.com
16.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	499	ebay.com
17.		Sony NEX-7	120 mm	67 mm	43 mm	400 g	430	n	Aug 2011	1,349	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. 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.

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. 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.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the A5100 is 2 percent smaller. They nevertheless have the same format factor of 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a slightly smaller sensor, the A5100 offers a higher resolution of 24 megapixels, compared with 12.2 MP of the X100. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.91μm versus 5.53μm for the X100). However, it should be noted that the A5100 is much more recent (by 3 years and 10 months) than the X100, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently.

The resolution advantage of the Sony A5100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A5100 for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Fujifilm X100 are 21.4 x 14.2 inches or 54.5 x 36.2 cm for good quality, 17.2 x 11.4 inches or 43.6 x 28.9 cm for very good quality, and 14.3 x 9.5 inches or 36.3 x 24.1 cm for excellent quality prints.

The A5100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Fujifilm FinePix X100 has a native sensitivity range from ISO 200 to ISO 6400, which can be extended to ISO 100-12800. The corresponding ISO settings for the Sony Alpha A5100 are ISO 100 to ISO 25600 (no boost).

Technology-wise, both cameras are equipped with CMOS (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 is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under consideration, the A5100 has a markedly higher DXO score than the X100 (overall score 7 points higher), which will translate into better image quality. The advantage is based on 0.9 bits higher color depth, 0.3 EV in additional dynamic range, and 0.4 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Fujifilm X100	APS-C	12.2	4288	2848	720/30p	22.9	12.4	1001	73
2.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
3.		Canon G1 X	1.5-inch	14.2	4352	3264	1080/24p	21.7	10.8	644	60
4.		Fujifilm X30	2/3	12.0	4000	3000	1080/60p	20.4	11.2	-312	49
5.		Fujifilm X100S	APS-C	16.0	4896	3264	1080/60p	23.3	12.5	1329	75
6.		Fujifilm X100T	APS-C	16.0	4896	3264	1080/60p	23.6	12.8	1483	78
7.		Fujifilm X100F	APS-C	24.0	6000	4000	1080/60p	23.9	13.2	1704	81
8.		Leica D-LUX Typ 109	Four Thirds	12.7	4112	3088	4K/30p	22.4	12.1	607	67
9.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
10.		Nikon D3100	APS-C	14.2	4608	3072	1080/24p	22.5	11.3	919	67
11.		Panasonic LX100	Four Thirds	12.7	4112	3088	4K/30p	22.3	12.5	553	67
12.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
13.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
14.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
15.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68
16.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
17.		Sony NEX-7	APS-C	24.0	6000	4000	1080/60i	24.1	13.4	1016	81
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 A5100 provides a better video resolution than the X100. It can shoot movie footage at 1080/60p, while the Fujifilm is limited to 720/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the X100 has an electronic viewfinder (1440k dots), which can be very helpful when shooting in bright sunlight. In contrast, the A5100 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Fujifilm X100 and Sony A5100 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.		Fujifilm X100	1440	n	2.8 / 460	fixed	n	1/4000s	5.0/s	Y	n
2.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
3.		Canon G1 X	optical	n	3.0 / 922	swivel	n	1/4000s	1.9/s	Y	Y
4.		Fujifilm X30	2360	n	3.0 / 920	tilting	n	1/4000s	12.0/s	Y	Y
5.		Fujifilm X100S	2360	n	2.8 / 460	fixed	n	1/4000s	6.0/s	Y	n
6.		Fujifilm X100T	2360	n	3.0 / 1040	fixed	n	1/4000s	6.0/s	Y	n
7.		Fujifilm X100F	2360	n	3.0 / 1040	fixed	n	1/4000s	8.0/s	Y	n
8.		Leica D-LUX Typ 109	2764	n	3.0 / 921	fixed	n	1/4000s	11.0/s	n	Y
9.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
10.		Nikon D3100	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
11.		Panasonic LX100	2764	n	3.0 / 921	fixed	n	1/4000s	11.0/s	n	Y
12.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
13.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
14.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
15.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
16.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
17.		Sony NEX-7	2359	n	3.0 / 921	tilting	n	1/4000s	10.0/s	Y	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A5100 has a touchscreen, while the X100 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The X100 writes its imaging data to SDXC cards, while the A5100 uses SDXC or Memory Stick PRO Duo cards. The A5100 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the X100 cannot take advantage of Ultra High Speed SD cards.

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 Fujifilm FinePix X100 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.		Fujifilm X100	Y	stereo / -	-	-	mini	2.0	-	-	-
2.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
3.		Canon G1 X	Y	stereo / mono	-	-	mini	2.0	-	-	-
4.		Fujifilm X30	Y	stereo / mono	-	-	micro	2.0	Y	-	-
5.		Fujifilm X100S	Y	stereo / mono	-	-	micro	2.0	-	-	-
6.		Fujifilm X100T	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
7.		Fujifilm X100F	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
8.		Leica D-LUX Typ 109	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
9.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
10.		Nikon D3100	Y	mono / mono	-	-	mini	2.0	-	-	-
11.		Panasonic LX100	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
12.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
13.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
14.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
15.		Sony NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-
16.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-
17.		Sony NEX-7	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the X100 has a hotshoe, while the A5100 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

Both the X100 and the A5100 have been discontinued, but can regularly be found used on ebay. The X100 was replaced by the Fujifilm X100S, while the A5100 does not have a direct successor. Further information on the features and operation of the X100 and A5100 can be found, respectively, in the Fujifilm X100 Manual (free pdf) or the online Sony A5100 Manual.

Review summary

So how do things add up? Is the Fujifilm X100 better than the Sony A5100 or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Fujifilm FinePix X100:

• Easier framing: Has an electronic viewfinder for image composition and settings control.
• Ready to shoot: Has a lens built-in, whereas the A5100 requires a separate lens.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• More heavily discounted: Has been available for much longer (launched in September 2010).

Reasons to prefer the Sony Alpha A5100:

• More detail: Has more megapixels (24 vs 12.2MP), which boosts linear resolution by 40%.
• Better image quality: Scores markedly higher (7 points) in the DXO overall evaluation.
• Better low-light sensitivity: Can shoot in dim conditions (0.4 stops ISO advantage).
• Better video: Provides higher definition movie capture (1080/60p vs 720/30p).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Larger screen: Has a bigger rear LCD (3.0" vs 2.8") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (922k vs 460k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (6 vs 5 flaps/sec) to capture the decisive moment.
• More flexible: Takes interchangeable lenses and can thus be used with specialty optics.
• More compact: Is smaller (110x63mm vs 126x75mm) and will fit more readily into a bag.
• Longer lasting: Gets more shots (400 versus 300) out of a single battery charge.
• Easier travel charging: Can be conveniently charged via its USB port.
• 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.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Reflects 3 years and 10 months of technical progress since the X100 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A5100 is the clear winner of the contest (19 : 4 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 wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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 Fujifilm X100 and the Sony A5100 place the cameras among the top in their class? Find out in the latest Best Prime Lens Compact Camera and Best Mirrorless Interchangeable Lens Camera listings 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 X100 or the A5100. 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.

Expert reviews

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], 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.		Fujifilm X100	3/5	..	..	75/100	4/5	5/5	Sep 2010	1,199	ebay.com
2.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
3.		Canon G1 X	5/5	+	..	76/100	4/5	4.5/5	Jan 2012	799	ebay.com
4.		Fujifilm X30	4/5	..	..	76/100	4.5/5	4.5/5	Aug 2014	599	ebay.com
5.		Fujifilm X100S	5/5	+ +	..	81/100	4.5/5	5/5	Jan 2013	1,299	ebay.com
6.		Fujifilm X100T	5/5	+	..	81/100	4.5/5	5/5	Sep 2014	1,299	ebay.com
7.		Fujifilm X100F	5/5	+	3.9/5	83/100	4.5/5	4.5/5	Jan 2017	1,299	ebay.com
8.		Leica D-LUX Typ 109	..	..	..	..	4.5/5	4.5/5	Sep 2014	1,195	ebay.com
9.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	599	ebay.com
10.		Nikon D3100	5/5	+ +	..	72/100	4.5/5	4.5/5	Aug 2010	599	ebay.com
11.		Panasonic LX100	5/5	+ +	..	85/100	5/5	5/5	Sep 2014	899	ebay.com
12.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
13.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	449	ebay.com
14.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
15.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	599	ebay.com
16.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	499	ebay.com
17.		Sony NEX-7	5/5	+ +	..	81/100	4.5/5	5/5	Aug 2011	1,349	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 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.

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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.

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