Nikon D3100 vs Canon 5D Mark III

The Nikon D3100 and the Canon EOS 5D Mark III are two digital cameras that were announced, respectively, in August 2010 and March 2012. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (D3100) and a full frame (5D Mark III) sensor. The Nikon has a resolution of 14.2 megapixels, whereas the Canon provides 22.1 MP.

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

Headline Specifications

Nikon D3100		Canon 5D Mark III
Digital single lens reflex		Digital single lens reflex
Nikon F mount lenses		Canon EF mount lenses
14.2 MP – APS-C sensor		22.1 MP – Full Frame sensor
1080/24p Video		1080/30p Video
ISO 100-3,200 (100 - 12,800)		ISO 100-25,600 (50 - 102,400)
Optical viewfinder		Optical viewfinder
3.0" LCD – 230k dots		3.2" LCD – 1040k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
3 shutter flaps per second		6 shutter flaps per second
not weather sealed		Weathersealed body
550 shots per battery charge		950 shots per battery charge
124 x 96 x 75 mm, 505 g		152 x 116 x 76 mm, 950 g

Check D3100 offers at
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Check 5D Mark III offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D3100 and the Canon EOS 5D Mark 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 Nikon D3100 and the Canon 5D Mark III. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth dimensions are rounded to the nearest millimeter.

The D3100 can be obtained in two different colors (black, red), while the 5D Mark III 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 Canon 5D Mark III is considerably larger (48 percent) than the Nikon D3100. Moreover, the 5D Mark III is substantially heavier (88 percent) than the D3100. It is noteworthy in this context that the 5D Mark III is splash and dust-proof, while the D3100 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. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Nikon Lens Catalog (D3100) and the Canon EF Lens Catalog (5D Mark III).

Concerning battery life, the D3100 gets 550 shots out of its Nikon EN-EL14 battery, while the 5D Mark III can take 950 images on a single charge of its Canon LP-E6 power pack.

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.		Nikon D3100	124 mm	96 mm	75 mm	505 g	550	n	Aug 2010	599	ebay.com
2.		Canon 5D Mark III	152 mm	116 mm	76 mm	950 g	950	Y	Mar 2012	3,499	ebay.com
3.		Canon 5D Mark II	152 mm	114 mm	75 mm	850 g	850	Y	Sep 2008	3,499	ebay.com
4.		Canon 5D Mark IV	151 mm	116 mm	76 mm	890 g	900	Y	Aug 2016	3,499	amazon.com
5.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
6.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
7.		Nikon D40	124 mm	94 mm	64 mm	522 g	470	n	Nov 2006	499	ebay.com
8.		Nikon D40X	124 mm	94 mm	64 mm	522 g	520	n	Mar 2007	729	ebay.com
9.		Nikon D60	126 mm	94 mm	64 mm	522 g	500	n	Jan 2008	629	ebay.com
10.		Nikon D610	141 mm	113 mm	82 mm	850 g	900	Y	Oct 2013	1,999	ebay.com
11.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	599	ebay.com
12.		Nikon D3200	125 mm	96 mm	77 mm	505 g	540	n	Apr 2012	599	ebay.com
13.		Nikon D5000	127 mm	104 mm	80 mm	590 g	510	n	Apr 2009	749	ebay.com
14.		Nikon D5100	128 mm	97 mm	79 mm	560 g	660	n	Apr 2011	749	ebay.com
15.		Nikon D7000	132 mm	105 mm	77 mm	780 g	1050	Y	Sep 2010	1,499	ebay.com
16.		Sony NEX-5N	111 mm	59 mm	38 mm	269 g	460	n	Aug 2011	699	ebay.com
17.		Sony NEX-C3	110 mm	60 mm	33 mm	225 g	400	n	Jun 2011	599	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

The price is, of course, an important factor in any camera decision. 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 D3100 was launched at a markedly lower price (by 83 percent) than the 5D Mark III, 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. 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.

Of the two cameras under consideration, the Nikon D3100 features an APS-C sensor and the Canon 5D Mark III a full frame sensor. The sensor area in the 5D Mark III is 143 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.

With 22.1MP, the 5D Mark III offers a higher resolution than the D3100 (14.2MP), but the 5D Mark III nevertheless has larger individual pixels (pixel pitch of 6.25μm versus 5.01μm for the D3100) due to its larger sensor. Moreover, the 5D Mark III is a somewhat more recent model (by 1 year and 6 months) than the D3100, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Canon 5D Mark III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 5D Mark III for good quality output (200 dots per inch) amounts to 28.8 x 19.2 inches or 73.2 x 48.8 cm, for very good quality (250 dpi) 23 x 15.4 inches or 58.5 x 39 cm, and for excellent quality (300 dpi) 19.2 x 12.8 inches or 48.8 x 32.5 cm. The corresponding values for the Nikon D3100 are 23 x 15.4 inches or 58.5 x 39 cm for good quality, 18.4 x 12.3 inches or 46.8 x 31.2 cm for very good quality, and 15.4 x 10.2 inches or 39 x 26 cm for excellent quality prints.

The Nikon D3100 has a native sensitivity range from ISO 100 to ISO 3200, which can be extended to ISO 100-12800. The corresponding ISO settings for the Canon EOS 5D Mark III are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-102400.

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.

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"). Of the two cameras under consideration, the 5D Mark III offers substantially better image quality than the D3100 (overall score 14 points higher). The advantage is based on 1.5 bits higher color depth, 0.4 EV in additional dynamic range, and 1.3 stops in additional low light sensitivity. 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.		Nikon D3100	APS-C	14.2	4608	3072	1080/24p	22.5	11.3	919	67
2.		Canon 5D Mark III	Full Frame	22.1	5760	3840	1080/30p	24.0	11.7	2293	81
3.		Canon 5D Mark II	Full Frame	21.0	5616	3744	1080/30p	23.7	11.9	1815	79
4.		Canon 5D Mark IV	Full Frame	30.1	6720	4480	4K/30p	24.8	13.6	2995	91
5.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
6.		Canon 5DS R	Full Frame	50.3	8688	5792	1080/30p	24.6	12.4	2308	86
7.		Nikon D40	APS-C	6.0	3008	2000	none	21.0	11.0	561	56
8.		Nikon D40X	APS-C	10.0	3872	2592	none	22.4	11.4	516	63
9.		Nikon D60	APS-C	10.0	3872	2592	none	22.5	11.4	562	65
10.		Nikon D610	Full Frame	24.2	6016	4016	1080/30p	25.1	14.4	2925	94
11.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
12.		Nikon D3200	APS-C	24.1	6016	4000	1080/30p	24.1	13.2	1131	81
13.		Nikon D5000	APS-C	12.2	4288	2848	720/24p	22.7	12.5	868	72
14.		Nikon D5100	APS-C	16.1	4928	3264	1080/30p	23.5	13.6	1183	80
15.		Nikon D7000	APS-C	16.1	4928	3264	1080/24p	23.5	13.9	1167	80
16.		Sony NEX-5N	APS-C	16.0	4912	3264	1080/60i	23.6	12.7	1079	77
17.		Sony NEX-C3	APS-C	16.0	4912	3264	720/30p	22.7	12.2	1083	73

Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the 5D Mark III provides a faster frame rate than the D3100. It can shoot movie footage at 1080/30p, while the Nikon is limited to 1080/24p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The D3100 and the 5D Mark III are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinder in the 5D Mark III offers a wider field of view (100%) than the one in the D3100 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the 5D Mark III has a higher magnification (0.71x vs 0.53x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Nikon D3100 and Canon 5D Mark III 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.		Nikon D3100	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
2.		Canon 5D Mark III	optical	Y	3.2 / 1040	fixed	n	1/8000s	6.0/s	n	n
3.		Canon 5D Mark II	optical	Y	3.0 / 920	fixed	n	1/8000s	3.9/s	n	n
4.		Canon 5D Mark IV	optical	Y	3.2 / 1620	fixed	Y	1/8000s	7.0/s	n	n
5.		Canon 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
6.		Canon 5DS R	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
7.		Nikon D40	optical	n	2.5 / 230	fixed	n	1/4000s	2.5/s	Y	n
8.		Nikon D40X	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
9.		Nikon D60	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
10.		Nikon D610	optical	Y	3.2 / 921	fixed	n	1/4000s	6.0/s	Y	n
11.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
12.		Nikon D3200	optical	n	3.0 / 921	fixed	n	1/4000s	4.0/s	Y	n
13.		Nikon D5000	optical	n	2.7 / 230	full-flex	n	1/4000s	4.0/s	Y	n
14.		Nikon D5100	optical	n	3.0 / 921	swivel	n	1/4000s	4.0/s	Y	n
15.		Nikon D7000	optical	Y	3.0 / 921	fixed	n	1/8000s	6.0/s	Y	n
16.		Sony NEX-5N	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
17.		Sony NEX-C3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	n	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 D3100 has one, while the 5D Mark III does not. While the built-in flash of the D3100 is not very powerful, it can at times be useful as a fill-in light.

The D3100 writes its imaging data to SDXC cards, while the 5D Mark III uses Compact Flash or SDXC cards. The 5D Mark III features dual card slots, which can be very useful in case a memory card fails. In contrast, the D3100 only has one slot.

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 Nikon D3100 and Canon EOS 5D Mark 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.		Nikon D3100	Y	mono / mono	-	-	mini	2.0	-	-	-
2.		Canon 5D Mark III	Y	mono / mono	Y	Y	mini	2.0	-	-	-
3.		Canon 5D Mark II	Y	mono / mono	Y	-	mini	2.0	-	-	-
4.		Canon 5D Mark IV	Y	mono / mono	Y	Y	mini	3.0	Y	Y	-
5.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
6.		Canon 5DS R	Y	mono / mono	Y	-	mini	3.0	-	-	-
7.		Nikon D40	Y	- / -	-	-	-	2.0	-	-	-
8.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
9.		Nikon D60	Y	- / -	-	-	-	2.0	-	-	-
10.		Nikon D610	Y	mono / mono	Y	Y	mini	2.0	-	-	-
11.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
12.		Nikon D3200	Y	mono / mono	Y	-	mini	2.0	-	-	-
13.		Nikon D5000	Y	mono / mono	-	-	mini	2.0	-	-	-
14.		Nikon D5100	Y	mono / mono	Y	-	mini	2.0	-	-	-
15.		Nikon D7000	Y	mono / mono	Y	-	mini	2.0	-	-	-
16.		Sony NEX-5N	Y	stereo / mono	-	-	mini	2.0	-	-	-
17.		Sony NEX-C3	Y	stereo / mono	-	-	mini	2.0	-	-	-

It is notable that the 5D Mark III has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The D3100 lacks such a headphone port.

Studio photographers will appreciate that the Canon 5D Mark III (unlike the D3100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the D3100 and the 5D Mark III have been discontinued, but can regularly be found used on ebay. The D3100 was replaced by the Nikon D3200, while the 5D Mark III was followed by the Canon 5D Mark IV. Further information on the features and operation of the D3100 and 5D Mark III can be found, respectively, in the Nikon D3100 Manual (free pdf) or the online Canon 5D Mark III Manual.

Review summary

So how do things add up? Which of the two cameras – the Nikon D3100 or the Canon 5D Mark III – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Nikon D3100:

• More compact: Is smaller (124x96mm vs 152x116mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 445g or 47 percent) and hence easier to carry around.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (83 percent cheaper at launch).
• More heavily discounted: Has been on the market for longer (launched in August 2010).

Advantages of the Canon EOS 5D Mark III:

• More detail: Has more megapixels (22.1 vs 14.2MP), which boosts linear resolution by 25%.
• Better image quality: Scores substantially higher (14 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.5 bits more color depth).
• Better low-light sensitivity: Can shoot in dim conditions (1.3 stops ISO advantage).
• Better video: Provides higher movie framerates (1080/30p versus 1080/24p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• More complete view: Has a viewfinder with a larger field of view (100% vs 95%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.53x).
• Easier setting verification: Features a control panel on top to check shooting parameters.
• 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 (1040k vs 230k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (6 vs 3 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (950 versus 550) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More modern: Was introduced somewhat (1 year and 6 months) more recently.

If the count of individual advantages (bullet points above) is taken as a guide, the 5D Mark III is the clear winner of the contest (19 : 5 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 Nikon D3100 and the Canon 5D Mark III place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing whether the two cameras rank among the cream of the crop.

In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the D3100 and the 5D Mark III in practical situations. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

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.		Nikon D3100	5/5	+ +	..	72/100	4.5/5	4.5/5	Aug 2010	599	ebay.com
2.		Canon 5D Mark III	..	+ +	..	82/100	4.5/5	4.5/5	Mar 2012	3,499	ebay.com
3.		Canon 5D Mark II	4/5	91/100	..	79/100	4/5	..	Sep 2008	3,499	ebay.com
4.		Canon 5D Mark IV	4.5/5	+ +	4/5	87/100	4.5/5	4.5/5	Aug 2016	3,499	amazon.com
5.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	3,699	ebay.com
6.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	3,699	ebay.com
7.		Nikon D40	..	81/100	..	+ +	o	4.5/5	Nov 2006	499	ebay.com
8.		Nikon D40X	..	79/100	..	+ +	4/5	4/5	Mar 2007	729	ebay.com
9.		Nikon D60	..	80/100	..	+ +	4/5	4.5/5	Jan 2008	629	ebay.com
10.		Nikon D610	4/5	+ +	..	87/100	4.5/5	4.5/5	Oct 2013	1,999	ebay.com
11.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	599	ebay.com
12.		Nikon D3200	5/5	+ +	..	73/100	4.5/5	4.5/5	Apr 2012	599	ebay.com
13.		Nikon D5000	..	+ +	..	75/100	4/5	4.5/5	Apr 2009	749	ebay.com
14.		Nikon D5100	5/5	+ +	..	76/100	4.5/5	4.5/5	Apr 2011	749	ebay.com
15.		Nikon D7000	4/5	..	..	80/100	4.5/5	4.5/5	Sep 2010	1,499	ebay.com
16.		Sony NEX-5N	3/5	+ +	..	79/100	4.5/5	4.5/5	Aug 2011	699	ebay.com
17.		Sony NEX-C3	3/5	+ +	..	74/100	4.5/5	4/5	Jun 2011	599	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. A score, therefore, has to be seen in close connection to the price and market introduction time 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.

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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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