Nikon D90 vs Sony A6100

The Nikon D90 and the Sony Alpha A6100 are two digital cameras that were officially introduced, respectively, in August 2008 and August 2019. The D90 is a DSLR, while the A6100 is a mirrorless interchangeable lens camera. Both cameras are equipped with an APS-C sensor. The Nikon 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

Nikon D90		Sony A6100
Digital single lens reflex		Mirrorless system camera
Nikon F mount lenses		Sony E mount lenses
12.2 MP – APS-C sensor		24 MP – APS-C sensor
720/24p Video		4K/30p Video
ISO 200-3,200 (200 - 6,400)		ISO 100-32,000 (100 - 51,200)
Optical viewfinder		Electronic viewfinder (1440k dots)
3.0" LCD – 920k dots		3.0" LCD – 922k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
4.5 shutter flaps per second		11 shutter flaps per second
850 shots per battery charge		420 shots per battery charge
132 x 103 x 77 mm, 703 g		120 x 67 x 59 mm, 396 g

Check D90 offers at
ebay.com
Check A6100 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D90 and the Sony Alpha A6100? 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 D90 and the Sony A6100. 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 A6100 can be obtained in three different colors (black, silver, white), while the D90 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 A6100 is considerably smaller (41 percent) than the Nikon D90. Moreover, the A6100 is substantially lighter (44 percent) than the D90. In this context, it is worth noting that neither the D90 nor the A6100 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. Both cameras have similarly sized sensors, but DSLRs have a larger flange-to-focal plane distance than mirrorless cameras, which imposes contraints on the optical engineering process and generally leads to bigger and heavier lenses. You can compare the optics available for the two cameras in the Nikon Lens Catalog (D90) and the Sony E-Mount Lens Catalog (A6100). Mirrorless cameras, such as the A6100, have moreover the advantage that they can use many lenses from other systems via adapters, as they have a relatively short flange to focal plane distance.

Concerning battery life, the D90 gets 850 shots out of its Nikon EN-EL3e battery, while the A6100 can take 420 images on a single charge of its Sony NP-FW50 power pack. The power pack in the A6100 can be charged via the USB port, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons 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.		Nikon D90	132 mm	103 mm	77 mm	703 g	850	n	Aug 2008	1,299	ebay.com
2.		Sony A6100	120 mm	67 mm	59 mm	396 g	420	n	Aug 2019	749	ebay.com
3.		Canon 40D	146 mm	108 mm	74 mm	822 g	750	n	Aug 2007	1,299	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 D80	132 mm	103 mm	77 mm	668 g	600	n	Aug 2006	999	ebay.com
7.		Nikon D300	147 mm	114 mm	74 mm	925 g	1000	Y	Aug 2007	1,799	ebay.com
8.		Nikon D300S	147 mm	115 mm	81 mm	938 g	950	Y	Jul 2009	1,799	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.		Nikon D5000	127 mm	104 mm	80 mm	590 g	510	n	Apr 2009	749	ebay.com
12.		Nikon D7000	132 mm	105 mm	77 mm	780 g	1050	Y	Sep 2010	1,499	ebay.com
13.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
14.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
15.		Sony A6400	120 mm	67 mm	50 mm	403 g	410	Y	Jan 2019	899	amazon.com
16.		Sony NEX-7	120 mm	67 mm	43 mm	400 g	430	n	Aug 2011	1,349	ebay.com
17.		Sony ZV-E10	115 mm	64 mm	45 mm	343 g	440	n	Jul 2021	699	amazon.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 retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The A6100 was launched at a markedly lower price (by 42 percent) than the D90, 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 sensor inside a digital camera is one of the key determinants of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixels in a sensor of the same technological generation. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its background. On the downside, larger sensors tend to be more expensive and 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 A6100 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 A6100 offers a higher resolution of 24 megapixels, compared with 12.2 MP of the D90. 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 D90). However, it should be noted that the A6100 is much more recent (by 11 years) than the D90, 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 A6100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A6100 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 Nikon D90 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 A6100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Nikon D90 has a native sensitivity range from ISO 200 to ISO 3200, which can be extended to ISO 200-6400. The corresponding ISO settings for the Sony Alpha A6100 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 100-51200.

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.

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 following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Nikon D90	APS-C	12.2	4288	2848	720/24p	22.7	12.5	977	73
2.		Sony A6100	APS-C	24.0	6000	4000	4K/30p	24.1	13.6	1947	84
3.		Canon 40D	APS-C	10.1	3888	2592	none	22.1	11.3	703	64
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 D80	APS-C	10.0	3872	2592	none	22.1	11.2	524	61
7.		Nikon D300	APS-C	12.2	4288	2848	none	22.1	12.0	679	67
8.		Nikon D300S	APS-C	12.2	4288	2848	720/24p	22.5	12.2	787	70
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.		Nikon D5000	APS-C	12.2	4288	2848	720/24p	22.7	12.5	868	72
12.		Nikon D7000	APS-C	16.1	4928	3264	1080/24p	23.5	13.9	1167	80
13.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
14.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
15.		Sony A6400	APS-C	24.0	6000	4000	4K/30p	24.0	13.6	1431	83
16.		Sony NEX-7	APS-C	24.0	6000	4000	1080/60i	24.1	13.4	1016	81
17.		Sony ZV-E10	APS-C	24.0	6000	4000	4K/30p	24.2	13.8	2134	85
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 can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the A6100 provides a better video resolution than the D90. It can shoot movie footage at 4K/30p, while the Nikon is limited to 720/24p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A6100 has an electronic viewfinder (1440k dots), while the D90 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 A6100 offers a wider field of view (100%) than the one in the D90 (96%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A6100 has a higher magnification (0.70x vs 0.63x), 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 D90 and Sony A6100 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 D90	optical	Y	3.0 / 920	fixed	n	1/4000s	4.5/s	Y	n
2.		Sony A6100	1440	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	n
3.		Canon 40D	optical	Y	3.0 / 230	fixed	n	1/8000s	6.5/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 D80	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
7.		Nikon D300	optical	Y	3.0 / 922	fixed	n	1/8000s	6.0/s	Y	n
8.		Nikon D300S	optical	Y	3.0 / 920	fixed	n	1/8000s	7.0/s	Y	n
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.		Nikon D5000	optical	n	2.7 / 230	full-flex	n	1/4000s	4.0/s	Y	n
12.		Nikon D7000	optical	Y	3.0 / 921	fixed	n	1/8000s	6.0/s	Y	n
13.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
14.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
15.		Sony A6400	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	n
16.		Sony NEX-7	2359	n	3.0 / 921	tilting	n	1/4000s	10.0/s	Y	n
17.		Sony ZV-E10	none	n	3.0 / 922	swivel	Y	1/4000s	11.0/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the D90, but is missing on the A6100 is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.

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 A6100 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 Sony A6100 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 D90 writes its imaging data to SDHC cards, while the A6100 uses SDXC or Memory Stick PRO Duo cards. The A6100 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the D90 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 Nikon D90 and Sony Alpha A6100 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 D90	Y	mono / mono	-	-	mini	2.0	-	-	-
2.		Sony A6100	Y	stereo / mono	Y	-	micro	2.0	Y	Y	Y
3.		Canon 40D	Y	- / -	-	-	-	2.0	-	-	-
4.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
5.		Nikon D60	Y	- / -	-	-	-	2.0	-	-	-
6.		Nikon D80	Y	- / -	-	-	-	2.0	-	-	-
7.		Nikon D300	Y	- / -	-	-	mini	2.0	-	-	-
8.		Nikon D300S	Y	stereo / mono	Y	-	mini	2.0	-	-	-
9.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
10.		Nikon D3100	Y	mono / mono	-	-	mini	2.0	-	-	-
11.		Nikon D5000	Y	mono / mono	-	-	mini	2.0	-	-	-
12.		Nikon D7000	Y	mono / mono	Y	-	mini	2.0	-	-	-
13.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
15.		Sony A6400	Y	stereo / mono	Y	-	micro	2.0	Y	Y	Y
16.		Sony NEX-7	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony ZV-E10	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y

It is notable that the A6100 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the D90 does not provide wifi capability.

Both the D90 and the A6100 have been discontinued, but can regularly be found used on ebay. The D90 was replaced by the Nikon D7000, while the A6100 was followed by the Sony A6600. Further information on the features and operation of the D90 and A6100 can be found, respectively, in the Nikon D90 Manual (free pdf) or the online Sony A6100 Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Nikon D90 and the Sony A6100? Which camera is better? The listing below highlights the relative strengths of the two models.

Advantages of the Nikon D90:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• Longer lasting: Can take more shots (850 versus 420) on a single battery charge.
• More heavily discounted: Has been available for much longer (launched in August 2008).

Arguments in favor of the Sony Alpha A6100:

• More detail: Has more megapixels (24 vs 12.2MP), which boosts linear resolution by 40%.
• Better video: Provides higher definition movie capture (4K/30p vs 720/24p).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Better sound: Can connect to an external microphone for higher quality sound recording.
• 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 96%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.70x vs 0.63x).
• 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 (11 vs 4.5 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.
• More compact: Is smaller (120x67mm vs 132x103mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 307g or 44 percent) and is thus easier to take along.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• 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.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More affordable: Was introduced into a lower priced category (42 percent cheaper at launch).
• More modern: Reflects 11 years of technical progress since the D90 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A6100 is the clear winner of the contest (23 : 4 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 Nikon D90 and the Sony A6100 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 remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the D90 or the A6100. 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 where reviews by experts come in. The adjacent summary-table relays the overall verdicts of several of the most popular 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.		Nikon D90	..	+ +	..	+ +	4/5	4.5/5	Aug 2008	1,299	ebay.com
2.		Sony A6100	..	..	4/5	82/100	4/5	5/5	Aug 2019	749	ebay.com
3.		Canon 40D	..	+ +	..	+ +	4.5/5	4.5/5	Aug 2007	1,299	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 D80	..	+	..	+ +	o	4.5/5	Aug 2006	999	ebay.com
7.		Nikon D300	..	+ +	..	+ +	5/5	4.5/5	Aug 2007	1,799	ebay.com
8.		Nikon D300S	5/5	+ +	..	82/100	4/5	4.5/5	Jul 2009	1,799	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.		Nikon D5000	..	+ +	..	75/100	4/5	4.5/5	Apr 2009	749	ebay.com
12.		Nikon D7000	4/5	..	..	80/100	4.5/5	4.5/5	Sep 2010	1,499	ebay.com
13.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
14.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
15.		Sony A6400	4/5	+	4/5	85/100	4.5/5	4/5	Jan 2019	899	amazon.com
16.		Sony NEX-7	5/5	+ +	..	81/100	4.5/5	5/5	Aug 2011	1,349	ebay.com
17.		Sony ZV-E10	4/5	..	4/5	82/100	4.5/5	4.5/5	Jul 2021	699	amazon.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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check D90 offers at
ebay.com
Check A6100 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 D90 offers at
ebay.com
Check A6100 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.