Panasonic G3 vs Nikon D3100

The Panasonic Lumix DMC-G3 and the Nikon D3100 are two digital cameras that were revealed to the public, respectively, in May 2011 and August 2010. The G3 is a mirrorless interchangeable lens camera, while the D3100 is a DSLR. The cameras are based on a Four Thirds (G3) and an APS-C (D3100) sensor. The Panasonic has a resolution of 15.8 megapixels, whereas the Nikon provides 14.2 MP.

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

Headline Specifications

Panasonic G3		Nikon D3100
Mirrorless system camera		Digital single lens reflex
Micro Four Thirds lenses		Nikon F mount lenses
15.8 MP – Four Thirds sensor		14.2 MP – APS-C sensor
1080/60i Video		1080/24p Video
ISO 160-6,400		ISO 100-3,200 (100 - 12,800)
Electronic viewfinder (1440k dots)		Optical viewfinder
3.0" LCD – 460k dots		3.0" LCD – 230k dots
Swivel touchscreen		Fixed screen (not touch-sensitive)
4 shutter flaps per second		3 shutter flaps per second
270 shots per battery charge		550 shots per battery charge
115 x 84 x 47 mm, 336 g		124 x 96 x 75 mm, 505 g

Check G3 offers at
ebay.com
Check D3100 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DMC-G3 and the Nikon D3100? 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 Panasonic G3 and the Nikon D3100 is provided in the side-by-side display below. 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 measures are rounded to the nearest millimeter.

The G3 can be obtained in four different colors (black, brown, red, white), while the D3100 is available in two color-versions (black, red).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Nikon D3100 is notably larger (23 percent) than the Panasonic G3. Moreover, the D3100 is substantially heavier (50 percent) than the G3. In this context, it is worth noting that neither the G3 nor the D3100 are weather-sealed.

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 Micro Four Thirds Lens Catalog (G3) and the Nikon Lens Catalog (D3100). Mirrorless cameras, such as the Panasonic G3, have moreover the advantage that they have a relatively short flange to focal plane distance and can thus use many lenses from other systems via adapters.

Concerning battery life, the G3 gets 270 shots out of its Panasonic DMW-BLD10 battery, while the D3100 can take 550 images on a single charge of its Nikon EN-EL14 power pack.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.		Panasonic G3	115 mm	84 mm	47 mm	336 g	270	n	May 2011	599	ebay.com
2.		Nikon D3100	124 mm	96 mm	75 mm	505 g	550	n	Aug 2010	599	ebay.com
3.		Nikon D3200	125 mm	96 mm	77 mm	505 g	540	n	Apr 2012	599	ebay.com
4.		Nikon D5100	128 mm	97 mm	79 mm	560 g	660	n	Apr 2011	749	ebay.com
5.		Nikon D7000	132 mm	105 mm	77 mm	780 g	1050	Y	Sep 2010	1,499	ebay.com
6.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	599	ebay.com
7.		Nikon D5000	127 mm	104 mm	80 mm	590 g	510	n	Apr 2009	749	ebay.com
8.		Panasonic G6	122 mm	85 mm	71 mm	390 g	340	n	Apr 2013	599	ebay.com
9.		Panasonic GF6	111 mm	65 mm	38 mm	323 g	340	n	Apr 2013	499	ebay.com
10.		Panasonic G5	120 mm	83 mm	71 mm	396 g	320	n	Jul 2012	599	ebay.com
11.		Panasonic GF3	108 mm	67 mm	32 mm	264 g	300	n	Jun 2011	549	ebay.com
12.		Panasonic GX1	116 mm	68 mm	39 mm	318 g	320	n	Nov 2011	699	ebay.com
13.		Panasonic G10	124 mm	84 mm	74 mm	388 g	380	n	Mar 2010	499	ebay.com
14.		Panasonic G2	124 mm	84 mm	74 mm	428 g	360	n	Mar 2010	599	ebay.com
15.		Panasonic GF2	113 mm	68 mm	33 mm	310 g	300	n	Nov 2010	549	ebay.com
16.		Panasonic GH2	124 mm	90 mm	76 mm	442 g	330	n	Sep 2010	899	ebay.com
17.		Panasonic G1	124 mm	84 mm	45 mm	360 g	410	n	Sep 2008	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

Any camera decision will obviously take relative prices into account. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The two cameras under review were launched at the same price and fall into the same 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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 more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Panasonic G3 features a Four Thirds sensor and the Nikon D3100 an APS-C sensor. The sensor area in the D3100 is 58 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.5. The sensor in the G3 has a native 4:3 aspect ratio, while the one in the D3100 offers a 3:2 aspect.

Despite having a smaller sensor, the Panasonic G3 offers a higher resolution of 15.8 megapixels, compared with 14.2 MP of the Nikon D3100. 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 3.77μm versus 5.01μm for the D3100). However, it should be noted that the G3 is a somewhat more recent model (by 8 months) than the D3100, and its sensor might have benefitted from technological advances during this time that partly offset its pixel-size disadvantage.

The Panasonic Lumix DMC-G3 has a native sensitivity range from ISO 160 to ISO 6400. The corresponding ISO settings for the Nikon D3100 are ISO 100 to ISO 3200, with the possibility to increase the ISO range to 100-12800.

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 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. Of the two cameras under consideration, the D3100 offers substantially better image quality than the G3 (overall score 11 points higher). The advantage is based on 1.5 bits higher color depth, 0.7 EV in additional dynamic range, and 0.5 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.		Panasonic G3	Four Thirds	15.8	4592	3448	1080/60i	21.0	10.6	667	56
2.		Nikon D3100	APS-C	14.2	4608	3072	1080/24p	22.5	11.3	919	67
3.		Nikon D3200	APS-C	24.1	6016	4000	1080/30p	24.1	13.2	1131	81
4.		Nikon D5100	APS-C	16.1	4928	3264	1080/30p	23.5	13.6	1183	80
5.		Nikon D7000	APS-C	16.1	4928	3264	1080/24p	23.5	13.9	1167	80
6.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
7.		Nikon D5000	APS-C	12.2	4288	2848	720/24p	22.7	12.5	868	72
8.		Panasonic G6	Four Thirds	15.9	4608	3456	1080/60p	21.3	11.5	639	61
9.		Panasonic GF6	Four Thirds	15.8	4592	3448	1080/60i	20.7	10.6	622	54
10.		Panasonic G5	Four Thirds	15.9	4608	3456	1080/60p	21.4	11.6	618	61
11.		Panasonic GF3	Four Thirds	12.0	4000	3000	1080/60i	20.6	10.1	459	50
12.		Panasonic GX1	Four Thirds	15.8	4592	3448	1080/60p	20.8	10.6	703	55
13.		Panasonic G10	Four Thirds	12.0	4000	3000	720/30p	21.2	10.1	411	52
14.		Panasonic G2	Four Thirds	12.0	4000	3000	720/30p	21.2	10.3	493	53
15.		Panasonic GF2	Four Thirds	12.0	4000	3000	1080/60i	21.2	10.3	506	54
16.		Panasonic GH2	Four Thirds	15.9	4608	3456	1080/60i	21.2	11.3	655	60
17.		Panasonic G1	Four Thirds	12.0	4000	3000	none	21.1	10.3	463	53

Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the G3 provides a higher frame rate than the D3100. It can shoot video footage at 1080/60i, while the Nikon is limited to 1080/24p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the G3 has an electronic viewfinder (1440k dots), while the D3100 has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinder in the G3 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 G3 has a higher magnification (0.70x vs 0.53x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The following table reports on some other key feature differences and similarities of the Panasonic G3, the Nikon D3100, 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.		Panasonic G3	1440	n	3.0 / 460	swivel	Y	1/4000s	4.0/s	Y	n
2.		Nikon D3100	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
3.		Nikon D3200	optical	n	3.0 / 921	fixed	n	1/4000s	4.0/s	Y	n
4.		Nikon D5100	optical	n	3.0 / 921	swivel	n	1/4000s	4.0/s	Y	n
5.		Nikon D7000	optical	Y	3.0 / 921	fixed	n	1/8000s	6.0/s	Y	n
6.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
7.		Nikon D5000	optical	n	2.7 / 230	full-flex	n	1/4000s	4.0/s	Y	n
8.		Panasonic G6	1440	n	3.0 / 1036	swivel	Y	1/4000s	7.0/s	Y	n
9.		Panasonic GF6	none	n	3.0 / 1040	tilting	Y	1/4000s	4.2/s	Y	n
10.		Panasonic G5	1440	n	3.0 / 920	swivel	Y	1/4000s	6.0/s	Y	n
11.		Panasonic GF3	none	n	3.0 / 460	fixed	Y	1/4000s	3.2/s	Y	n
12.		Panasonic GX1	optional	n	3.0 / 460	fixed	Y	1/4000s	4.2/s	Y	n
13.		Panasonic G10	202	n	3.0 / 460	fixed	n	1/4000s	2.6/s	Y	n
14.		Panasonic G2	1440	n	3.0 / 460	swivel	Y	1/4000s	2.6/s	Y	n
15.		Panasonic GF2	optional	n	3.0 / 460	fixed	Y	1/4000s	2.6/s	Y	n
16.		Panasonic GH2	1534	n	3.0 / 460	swivel	n	1/4000s	3.0/s	Y	n
17.		Panasonic G1	1440	n	3.0 / 460	swivel	n	1/4000s	3.0/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 G3 has a touchscreen, while the D3100 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

Concerning the storage of imaging data, both the G3 and the D3100 write their files to SDXC 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 Panasonic Lumix DMC-G3 and Nikon D3100 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.		Panasonic G3	Y	stereo / mono	-	-	mini	2.0	-	-	-
2.		Nikon D3100	Y	mono / mono	-	-	mini	2.0	-	-	-
3.		Nikon D3200	Y	mono / mono	Y	-	mini	2.0	-	-	-
4.		Nikon D5100	Y	mono / mono	Y	-	mini	2.0	-	-	-
5.		Nikon D7000	Y	mono / mono	Y	-	mini	2.0	-	-	-
6.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
7.		Nikon D5000	Y	mono / mono	-	-	mini	2.0	-	-	-
8.		Panasonic G6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
9.		Panasonic GF6	-	stereo / mono	-	-	mini	2.0	Y	Y	-
10.		Panasonic G5	Y	stereo / mono	-	-	mini	2.0	-	-	-
11.		Panasonic GF3	-	stereo / mono	-	-	mini	2.0	-	-	-
12.		Panasonic GX1	Y	stereo / mono	-	-	mini	2.0	-	-	-
13.		Panasonic G10	Y	mono / -	-	-	mini	2.0	-	-	-
14.		Panasonic G2	Y	stereo / mono	-	-	mini	2.0	-	-	-
15.		Panasonic GF2	Y	stereo / mono	-	-	mini	2.0	-	-	-
16.		Panasonic GH2	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Panasonic G1	Y	- / -	-	-	mini	2.0	-	-	-

Both the G3 and the D3100 have been discontinued, but can regularly be found used on ebay. The D3100 was replaced by the Nikon D3200, while the G3 was followed by the Panasonic G5. Further information on the features and operation of the G3 and D3100 can be found, respectively, in the Panasonic G3 Manual (free pdf) or the online Nikon D3100 Manual.

Review summary

So how do things add up? Is the Panasonic G3 better than the Nikon D3100 or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Panasonic Lumix DMC-G3:

• Better video: Provides higher movie framerates (1080/60i versus 1080/24p).
• More framing info: Has an electronic viewfinder that displays shooting data.
• 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 (0.70x vs 0.53x).
• More detailed LCD: Has a higher resolution rear screen (460k vs 230k dots).
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (4 vs 3 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (115x84mm vs 124x96mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 169g or 33 percent) and hence easier to carry around.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• More modern: Is somewhat more recent (announced 8 months after the D3100).

Reasons to prefer the Nikon D3100:

• Better image quality: Scores substantially higher (11 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.5 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (0.7 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (0.5 stops ISO advantage).
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Longer lasting: Gets more shots (550 versus 270) out of a single battery charge.
• More heavily discounted: Has been on the market for longer (launched in August 2010).

If the number of relative strengths (bullet points above) is taken as a guide, the G3 is the clear winner of the match-up (13 : 7 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 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 Panasonic G3 and the Nikon D3100 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR Camera listings 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 says little about, for example, the shooting experience and imaging performance of the G3 and the D3100 in practical situations. 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 hands-on reviews by experts 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.		Panasonic G3	3/5	+ +	..	75/100	4.5/5	5/5	May 2011	599	ebay.com
2.		Nikon D3100	5/5	+ +	..	72/100	4.5/5	4.5/5	Aug 2010	599	ebay.com
3.		Nikon D3200	5/5	+ +	..	73/100	4.5/5	4.5/5	Apr 2012	599	ebay.com
4.		Nikon D5100	5/5	+ +	..	76/100	4.5/5	4.5/5	Apr 2011	749	ebay.com
5.		Nikon D7000	4/5	..	..	80/100	4.5/5	4.5/5	Sep 2010	1,499	ebay.com
6.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	599	ebay.com
7.		Nikon D5000	..	+ +	..	75/100	4/5	4.5/5	Apr 2009	749	ebay.com
8.		Panasonic G6	4/5	+ +	..	..	5/5	4.5/5	Apr 2013	599	ebay.com
9.		Panasonic GF6	..	+ +	..	..	4.5/5	4.5/5	Apr 2013	499	ebay.com
10.		Panasonic G5	3/5	+ +	..	..	4.5/5	4.5/5	Jul 2012	599	ebay.com
11.		Panasonic GF3	3/5	82/100	..	71/100	4.5/5	4/5	Jun 2011	549	ebay.com
12.		Panasonic GX1	3/5	+	..	77/100	4.5/5	4.5/5	Nov 2011	699	ebay.com
13.		Panasonic G10	3/5	..	..	70/100	4/5	4/5	Mar 2010	499	ebay.com
14.		Panasonic G2	..	..	..	72/100	4/5	4.5/5	Mar 2010	599	ebay.com
15.		Panasonic GF2	3/5	82/100	..	70/100	4.5/5	4.5/5	Nov 2010	549	ebay.com
16.		Panasonic GH2	5/5	+ +	..	79/100	4.5/5	5/5	Sep 2010	899	ebay.com
17.		Panasonic G1	..	+ +	..	70/100	4/5	4.5/5	Sep 2008	599	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date 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 G3 offers at
ebay.com
Check D3100 offers at
ebay.com

Other camera comparisons

Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

~

Check G3 offers at
ebay.com
Check D3100 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.