Nikon D3100 vs Pentax Q

The Nikon D3100 and the Pentax Q are two digital cameras that were announced, respectively, in August 2010 and June 2011. The D3100 is a DSLR, while the Pentax Q is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (D3100) and a 1/2.3-inch (Pentax Q) sensor. The Nikon has a resolution of 14.2 megapixels, whereas the Pentax provides 12 MP.

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

Headline Specifications

Nikon D3100		Pentax Q
Digital single lens reflex		Mirrorless system camera
Nikon F mount lenses		Pentax Q mount lenses
14.2 MP – APS-C sensor		12 MP – 1/2.3" sensor
1080/24p Video		1080/30p Video
ISO 100-3,200 (100 - 12,800)		ISO 125-6,400
Optical viewfinder		Viewfinder optional
3.0" LCD – 230k dots		3.0" LCD – 460k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
3 shutter flaps per second		1.5 shutter flaps per second
Lens stabilization only		In-body stabilization
550 shots per battery charge		230 shots per battery charge
124 x 96 x 75 mm, 505 g		98 x 57 x 31 mm, 180 g

Check D3100 offers at
ebay.com
Check Pentax Q offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D3100 and the Pentax Q? 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 Nikon D3100 and the Pentax Q 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 D3100 can be obtained in two different colors (black, red), while the Pentax Q is also available in two color-versions, but different ones (black, white).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax Q is considerably smaller (53 percent) than the Nikon D3100. Moreover, the Pentax Q is substantially lighter (64 percent) than the D3100. In this context, it is worth noting that neither the D3100 nor the Pentax Q 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. 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.

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.		Pentax Q	98 mm	57 mm	31 mm	180 g	230	n	Jun 2011	649	ebay.com
3.		Nikon D40	124 mm	94 mm	64 mm	522 g	470	n	Nov 2006	499	ebay.com
4.		Nikon D40X	124 mm	94 mm	64 mm	522 g	520	n	Mar 2007	729	ebay.com
5.		Nikon D60	126 mm	94 mm	64 mm	522 g	500	n	Jan 2008	629	ebay.com
6.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	599	ebay.com
7.		Nikon D3200	125 mm	96 mm	77 mm	505 g	540	n	Apr 2012	599	ebay.com
8.		Nikon D5000	127 mm	104 mm	80 mm	590 g	510	n	Apr 2009	749	ebay.com
9.		Nikon D5100	128 mm	97 mm	79 mm	560 g	660	n	Apr 2011	749	ebay.com
10.		Nikon D7000	132 mm	105 mm	77 mm	780 g	1050	Y	Sep 2010	1,499	ebay.com
11.		Olympus E-620	130 mm	94 mm	60 mm	521 g	500	n	Feb 2009	699	ebay.com
12.		Olympus E-PL1	115 mm	72 mm	42 mm	334 g	290	n	Feb 2010	599	ebay.com
13.		Olympus E-PL2	114 mm	72 mm	42 mm	362 g	280	n	Jan 2011	599	ebay.com
14.		Olympus E-PL3	110 mm	64 mm	37 mm	313 g	300	n	Jun 2011	599	ebay.com
15.		Olympus XZ-2	113 mm	65 mm	48 mm	346 g	340	n	Sep 2012	599	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

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. The D3100 was somewhat cheaper (by 8 percent) than the Pentax Q at launch, but both cameras fall into the same price category. 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 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Nikon D3100 features an APS-C sensor and the Pentax Q a 1/2.3-inch sensor. The sensor area in the Pentax Q is 92 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 5.6. The sensor in the D3100 has a native 3:2 aspect ratio, while the one in the Pentax Q offers a 4:3 aspect.

With 14.2MP, the D3100 offers a higher resolution than the Pentax Q (12MP), but the D3100 nevertheless has larger individual pixels (pixel pitch of 5.01μm versus 1.53μm for the Pentax Q) due to its larger sensor. However, the Pentax Q is a somewhat more recent model (by 10 months) than the D3100, and its sensor might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels.

The resolution advantage of the Nikon D3100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the D3100 for good quality output (200 dots per inch) amounts to 23 x 15.4 inches or 58.5 x 39 cm, for very good quality (250 dpi) 18.4 x 12.3 inches or 46.8 x 31.2 cm, and for excellent quality (300 dpi) 15.4 x 10.2 inches or 39 x 26 cm. The corresponding values for the Pentax Q are 20 x 15 inches or 50.8 x 38.1 cm for good quality, 16 x 12 inches or 40.6 x 30.5 cm for very good quality, and 13.3 x 10 inches or 33.9 x 25.4 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 Pentax Q are ISO 125 to ISO 6400 (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 review, the D3100 provides substantially higher image quality than the Pentax Q, with an overall score that is 20 points higher. This advantage is based on 2.3 bits higher color depth, 0.2 EV in additional dynamic range, and 2.3 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.		Nikon D3100	APS-C	14.2	4608	3072	1080/24p	22.5	11.3	919	67
2.		Pentax Q	1/2.3	12.0	4000	3000	1080/30p	20.2	11.1	189	47
3.		Nikon D40	APS-C	6.0	3008	2000	none	21.0	11.0	561	56
4.		Nikon D40X	APS-C	10.0	3872	2592	none	22.4	11.4	516	63
5.		Nikon D60	APS-C	10.0	3872	2592	none	22.5	11.4	562	65
6.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
7.		Nikon D3200	APS-C	24.1	6016	4000	1080/30p	24.1	13.2	1131	81
8.		Nikon D5000	APS-C	12.2	4288	2848	720/24p	22.7	12.5	868	72
9.		Nikon D5100	APS-C	16.1	4928	3264	1080/30p	23.5	13.6	1183	80
10.		Nikon D7000	APS-C	16.1	4928	3264	1080/24p	23.5	13.9	1167	80
11.		Olympus E-620	Four Thirds	12.2	4032	3024	none	21.3	10.3	536	55
12.		Olympus E-PL1	Four Thirds	12.2	4032	3024	720/30p	21.5	10.1	487	54
13.		Olympus E-PL2	Four Thirds	12.2	4032	3024	720/30p	21.4	10.2	573	55
14.		Olympus E-PL3	Four Thirds	12.2	4032	3024	1080/60i	20.9	10.3	499	52
15.		Olympus XZ-2	1/1.7	11.8	3968	2976	1080/30p	20.4	11.3	216	49
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 are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the Pentax Q 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 range of features. For example, the D3100 has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the Pentax Q relies on live view and the rear LCD for framing. That said, the Pentax Q can be equipped with an optional viewfinder – the O-VF1. The table below summarizes some of the other core capabilities of the Nikon D3100 and Pentax Q 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.		Nikon D3100	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
2.		Pentax Q	optional	n	3.0 / 460	fixed	n	1/2000s	1.5/s	Y	Y
3.		Nikon D40	optical	n	2.5 / 230	fixed	n	1/4000s	2.5/s	Y	n
4.		Nikon D40X	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
5.		Nikon D60	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
6.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
7.		Nikon D3200	optical	n	3.0 / 921	fixed	n	1/4000s	4.0/s	Y	n
8.		Nikon D5000	optical	n	2.7 / 230	full-flex	n	1/4000s	4.0/s	Y	n
9.		Nikon D5100	optical	n	3.0 / 921	swivel	n	1/4000s	4.0/s	Y	n
10.		Nikon D7000	optical	Y	3.0 / 921	fixed	n	1/8000s	6.0/s	Y	n
11.		Olympus E-620	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
12.		Olympus E-PL1	optional	n	2.7 / 230	fixed	n	1/2000s	3.0/s	Y	Y
13.		Olympus E-PL2	optional	n	3.0 / 460	fixed	n	1/4000s	3.0/s	Y	Y
14.		Olympus E-PL3	optional	n	3.0 / 460	tilting	n	1/4000s	5.5/s	n	Y
15.		Olympus XZ-2	optional	n	3.0 / 920	tilting	Y	1/2000s	5.0/s	Y	Y
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 feature that differentiates the Pentax Q and the D3100 is in-body image stabilization (IBIS). The Pentax Q reduces the risk of handshake-induced blur with all attached lenses, while the D3100 offers no blur reduction with lenses that themselves do not provide optical image stabilization.

The Pentax Q 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.

Concerning the storage of imaging data, both the D3100 and the Pentax Q 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 Nikon D3100 and Pentax Q 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.		Pentax Q	Y	mono / mono	-	-	mini	2.0	-	-	-
3.		Nikon D40	Y	- / -	-	-	-	2.0	-	-	-
4.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
5.		Nikon D60	Y	- / -	-	-	-	2.0	-	-	-
6.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
7.		Nikon D3200	Y	mono / mono	Y	-	mini	2.0	-	-	-
8.		Nikon D5000	Y	mono / mono	-	-	mini	2.0	-	-	-
9.		Nikon D5100	Y	mono / mono	Y	-	mini	2.0	-	-	-
10.		Nikon D7000	Y	mono / mono	Y	-	mini	2.0	-	-	-
11.		Olympus E-620	Y	- / -	-	-	-	2.0	-	-	-
12.		Olympus E-PL1	Y	stereo / -	-	-	mini	2.0	-	-	-
13.		Olympus E-PL2	Y	stereo / -	-	-	mini	2.0	-	-	-
14.		Olympus E-PL3	Y	stereo / -	-	-	mini	2.0	-	-	-
15.		Olympus XZ-2	Y	stereo / mono	-	-	mini	2.0	-	-	-
16.		Sony NEX-5N	Y	stereo / mono	-	-	mini	2.0	-	-	-
17.		Sony NEX-C3	Y	stereo / mono	-	-	mini	2.0	-	-	-

Both the D3100 and the Pentax Q have been discontinued, but can regularly be found used on ebay. The D3100 was replaced by the Nikon D3200, while the Pentax Q was followed by the Pentax Q10. Further information on the features and operation of the D3100 and Pentax Q can be found, respectively, in the Nikon D3100 Manual (free pdf) or the online Pentax Q Manual.

Review summary

So how do things add up? Is the Nikon D3100 better than the Pentax Q or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Nikon D3100:

• More detail: Offers more megapixels (14.2 vs 12MP) with a 11% higher linear resolution.
• Better image quality: Scores substantially higher (20 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (2.3 bits more color depth).
• Better low-light sensitivity: Requires less light for good images (2.3 stops ISO advantage).
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
• Faster burst: Shoots at higher frequency (3 vs 1.5 flaps/sec) to capture the decisive moment.
• Longer lasting: Can take more shots (550 versus 230) on a single battery charge.
• More heavily discounted: Has been on the market for longer (launched in August 2010).

Reasons to prefer the Pentax Q:

• Better video: Provides higher movie framerates (1080/30p versus 1080/24p).
• More detailed LCD: Has a higher resolution rear screen (460k vs 230k dots).
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (98x57mm vs 124x96mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 325g or 64 percent) and is thus easier to take along.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• More modern: Was introduced somewhat (10 months) more recently.

If the count of individual advantages (bullet points above) is taken as a guide, the D3100 comes out slightly ahead of the Pentax Q (9 : 8 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 Nikon D3100 and the Pentax Q place the cameras among the top in their class? Find out in the latest Best DSLR 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 says little about, for example, the shooting experience and imaging performance of the D3100 and the Pentax Q 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 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.		Pentax Q	3/5	..	..	..	4/5	3.5/5	Jun 2011	649	ebay.com
3.		Nikon D40	..	81/100	..	+ +	o	4.5/5	Nov 2006	499	ebay.com
4.		Nikon D40X	..	79/100	..	+ +	4/5	4/5	Mar 2007	729	ebay.com
5.		Nikon D60	..	80/100	..	+ +	4/5	4.5/5	Jan 2008	629	ebay.com
6.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	599	ebay.com
7.		Nikon D3200	5/5	+ +	..	73/100	4.5/5	4.5/5	Apr 2012	599	ebay.com
8.		Nikon D5000	..	+ +	..	75/100	4/5	4.5/5	Apr 2009	749	ebay.com
9.		Nikon D5100	5/5	+ +	..	76/100	4.5/5	4.5/5	Apr 2011	749	ebay.com
10.		Nikon D7000	4/5	..	..	80/100	4.5/5	4.5/5	Sep 2010	1,499	ebay.com
11.		Olympus E-620	3/5	88/100	..	72/100	4.5/5	5/5	Feb 2009	699	ebay.com
12.		Olympus E-PL1	..	86/100	..	69/100	4/5	4.5/5	Feb 2010	599	ebay.com
13.		Olympus E-PL2	3/5	83/100	..	71/100	4.5/5	4.5/5	Jan 2011	599	ebay.com
14.		Olympus E-PL3	3/5	+ +	..	72/100	4.5/5	4/5	Jun 2011	599	ebay.com
15.		Olympus XZ-2	4/5	+	..	..	4.5/5	4.5/5	Sep 2012	599	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 review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. 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.

Check D3100 offers at
ebay.com
Check Pentax Q offers at
ebay.com

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.

~

Check D3100 offers at
ebay.com
Check Pentax Q 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.