Pentax WG-90 vs Sony A77

The Pentax WG-90 and the Sony Alpha SLT-A77 are two digital cameras that were officially introduced, respectively, in November 2023 and August 2011. The WG-90 is a fixed lens compact, while the A77 is a DSLR. The cameras are based on a 1/2.3-inch (WG-90) and an APS-C (A77) sensor. The Pentax has a resolution of 15.9 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

Pentax WG-90		Sony A77
Fixed lens compact camera		Digital single lens reflex
28-140mm f/3.5-5.5		Sony A mount lenses
15.9 MP – 1/2.3" sensor		24 MP – APS-C sensor
1080/60p Video		1080/60p Video
ISO 125-6,400		ISO 100-16,000 (50 - 25,600)
No viewfinder, LCD framing		Electronic viewfinder (2359k dots)
2.7" LCD – 230k dots		3.0" LCD – 921k dots
Fixed screen (not touch-sensitive)		Fully flexible screen (no touchscreen)
8 shutter flaps per second		12 shutter flaps per second
no shake reduction		In-body stabilization
Waterproof body (14m)		Weathersealed body
300 shots per battery charge		470 shots per battery charge
123 x 62 x 30 mm, 194 g		143 x 104 x 81 mm, 732 g

Check WG-90 price at
amazon.com
Check A77 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax WG-90 and the Sony Alpha SLT-A77? 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 physical size and weight of the Pentax WG-90 and the Sony A77 are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.

The WG-90 can be obtained in two different colors (black, blue), while the A77 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 A77 is considerably larger (95 percent) than the Pentax WG-90. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments. More than that, the WG-90 is water-proof up to 14m and can, thus, be used for underwater photography.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the WG-90 has a lens built in, whereas the A77 is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Pentax WG-90	123 mm	62 mm	30 mm	194 g	300	Y	Nov 2023	US$ 279	amazon.com
2.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	US$ 1 399	ebay.com
3.		Canon SX600	104 mm	61 mm	26 mm	188 g	290	n	Jan 2014	US$ 249	ebay.com
4.		Fujifilm XP120	110 mm	71 mm	28 mm	203 g	210	Y	Jan 2017	US$ 229	ebay.com
5.		Fujifilm XP130	110 mm	71 mm	28 mm	207 g	240	Y	Jan 2018	US$ 229	ebay.com
6.		Fujifilm XP140	110 mm	71 mm	28 mm	207 g	240	Y	Feb 2019	US$ 229	ebay.com
7.		Nikon W300	112 mm	66 mm	29 mm	231 g	280	Y	May 2017	US$ 389	ebay.com
8.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	US$ 1 999	ebay.com
9.		Pentax WG-8	118 mm	66 mm	33 mm	242 g	340	Y	Jun 2024	US$ 399	amazon.com
10.		Pentax WG-1000	116 mm	69 mm	51 mm	220 g	300	Y	Jun 2024	US$ 229	amazon.com
11.		Ricoh WG-60	123 mm	62 mm	30 mm	193 g	300	Y	Oct 2018	US$ 279	ebay.com
12.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	US$ 1 999	ebay.com
13.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	US$ 4 499	ebay.com
14.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	US$ 1 199	ebay.com
15.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	US$ 2 799	ebay.com
16.		Sony RX0	59 mm	41 mm	30 mm	110 g	240	Y	Aug 2017	US$ 699	ebay.com
17.		Sony WX800	102 mm	58 mm	36 mm	233 g	370	n	Oct 2018	US$ 399	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
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The price is, of course, an important factor in any camera decision. 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 WG-90 was launched at a lower price than the A77, despite having a lens built in. 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. 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 more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Pentax WG-90 features a 1/2.3-inch sensor and the Sony A77 an APS-C sensor. The sensor area in the A77 is 1211 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 5.6 and 1.5. The sensor in the WG-90 has a native 4:3 aspect ratio, while the one in the A77 offers a 3:2 aspect.

With 24MP, the A77 offers a higher resolution than the WG-90 (15.9MP), but the A77 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 1.33μm for the WG-90) due to its larger sensor. However, the WG-90 is a much more recent model (by 12 years and 2 months) than the A77, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the WG-90 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A77 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A77 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 Pentax WG-90 are 23 x 17.3 inches or 58.5 x 43.9 cm for good quality, 18.4 x 13.8 inches or 46.8 x 35.1 cm for very good quality, and 15.4 x 11.5 inches or 39 x 29.3 cm for excellent quality prints.

The Pentax WG-90 has a native sensitivity range from ISO 125 to ISO 6400. The corresponding ISO settings for the Sony Alpha SLT-A77 are ISO 100 to ISO 16000, with the possibility to increase the ISO range to 50-25600.

In terms of underlying technology, the WG-90 is build around a BSI-CMOS sensor, while the A77 uses a CMOS imager. 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 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"). 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.		Pentax WG-90	1/2.3	15.9	4608	3456	1080/60p	20.9	12.8	1570	54
2.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
3.		Canon SX600	1/2.3	15.9	4608	3456	1080/30p	20.0	11.4	620	45
4.		Fujifilm XP120	1/2.3	15.9	4608	3456	1080/60p	20.5	11.9	900	49
5.		Fujifilm XP130	1/2.3	15.9	4608	3456	1080/60p	20.6	12.1	1000	51
6.		Fujifilm XP140	1/2.3	15.9	4608	3456	4K/15p	20.7	12.2	1102	52
7.		Nikon W300	1/2.3	15.9	4608	3456	4K/30p	20.5	12.0	938	50
8.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
9.		Pentax WG-8	1/2.3	20.2	5184	3888	4K/30p	20.9	12.8	1626	54
10.		Pentax WG-1000	1/2.3	15.9	4608	3456	1080/30p	20.9	12.8	1626	54
11.		Ricoh WG-60	1/2.3	15.9	4608	3456	1080/60p	20.6	12.2	1072	51
12.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
13.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
14.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
15.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
16.		Sony RX0	1-inch	15.4	4800	3200	1080/60p	22.4	12.4	548	68
17.		Sony WX800	1/2.3	18.0	4896	3672	4K/30p	20.6	12.2	1070	51
Note: DXO values in italics represent estimates based on sensor size and age.

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 A77 provides a faster frame rate than the WG-90. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/60p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the A77 has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the WG-90 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Pentax WG-90 and Sony A77 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.		Pentax WG-90	none	n	2.7 / 230	fixed	n	1/4000s	8.0/s	Y	n
2.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
3.		Canon SX600	none	n	3.0 / 461	fixed	n	1/2000s	3.9/s	Y	Y
4.		Fujifilm XP120	none	n	3.0 / 920	fixed	n	1/2000s	10.0/s	Y	Y
5.		Fujifilm XP130	none	n	3.0 / 920	fixed	n	1/2000s	10.0/s	Y	Y
6.		Fujifilm XP140	none	n	3.0 / 920	fixed	n	1/2000s	10.0/s	Y	Y
7.		Nikon W300	none	n	3.0 / 921	fixed	n	1/4000s	7.0/s	Y	Y
8.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
9.		Pentax WG-8	none	n	3.0 / 1040	fixed	n	1/4000s	8.0/s	Y	n
10.		Pentax WG-1000	none	n	2.7 / 230	fixed	n	1/2000s	8.0/s	Y	n
11.		Ricoh WG-60	none	n	2.7 / 230	fixed	n	1/4000s	8.0/s	Y	n
12.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
14.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
15.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
16.		Sony RX0	none	n	1.5 / 230	fixed	n	..	5.5/s	n	n
17.		Sony WX800	none	n	3.0 / 922	tilting	Y	1/2000s	10.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the A77, but is missing on the WG-90 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 Pentax WG-90 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 WG-90 writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. The A77 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the WG-90 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 Pentax WG-90 and Sony Alpha SLT-A77 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.		Pentax WG-90	-	mono / mono	-	-	micro	2.0	-	-	-
2.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
3.		Canon SX600	-	mono / mono	-	-	micro	2.0	Y	Y	-
4.		Fujifilm XP120	-	mono / mono	-	-	micro	2.0	Y	-	-
5.		Fujifilm XP130	-	mono / mono	-	-	micro	2.0	Y	-	Y
6.		Fujifilm XP140	-	mono / mono	-	-	micro	2.0	Y	-	Y
7.		Nikon W300	-	stereo / mono	-	-	micro	2.0	Y	-	Y
8.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
9.		Pentax WG-8	-	mono / mono	-	-	-	3.0	-	-	-
10.		Pentax WG-1000	-	mono / mono	-	-	-	2.0	-	-	-
11.		Ricoh WG-60	-	mono / mono	-	-	micro	2.0	-	-	-
12.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
14.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
15.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
16.		Sony RX0	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
17.		Sony WX800	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the A77 has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The WG-90 does not feature such a mic input.

Studio photographers will appreciate that the Sony A77 (unlike the WG-90) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Travel and landscape photographers will find it useful that the A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The WG-90 is a recent model that features in the current product line-up of Pentax. In contrast, the A77 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the A77 was succeeded by the Sony A77 II. Further information on the features and operation of the WG-90 and A77 can be found, respectively, in the Pentax WG-90 Manual (free pdf) or the online Sony A77 Manual.

Review summary

So what is the bottom line? Is there a clear favorite between the Pentax WG-90 and the Sony A77? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Pentax WG-90:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Ready to shoot: Comes with a built-in lens, while the A77 requires a separate lens.
• More compact: Is smaller (123x62mm vs 143x104mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the A77).
• Water-proof: Is rugged and sealed and can thus be used for underwater photography (up to 14m).
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 12 years and 2 months of technical progress since the A77 launch.

Reasons to prefer the Sony Alpha SLT-A77:

• More detail: Has more megapixels (24 vs 15.9MP), which boosts linear resolution by 25%.
• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
• Richer colors: The pixel size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
• Better video: Provides higher movie framerates (1080/60p versus 1080/60p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.0" vs 2.7") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (921k vs 230k dots).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 8 flaps/sec) to capture the decisive moment.
• More flexible: Makes it possible to change lenses and thus to use specialty optics.
• Longer lasting: Gets more shots (470 versus 300) out of a single battery charge.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More heavily discounted: Has been around for much longer (launched in August 2011).

If the number of relative strengths (bullet points above) is taken as a guide, the A77 is the clear winner of the contest (24 : 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 Pentax WG-90 and the Sony A77 place the cameras among the top in their class? Find out in the latest Best Travel-Zoom Camera and Best DSLR 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 WG-90 or the A77. 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	Street Price
1.		Pentax WG-90	..	..	..	..	..	..	Nov 2023	US$ 279	amazon.com
2.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	US$ 1 399	ebay.com
3.		Canon SX600	..	+	..	..	4/5	4/5	Jan 2014	US$ 249	ebay.com
4.		Fujifilm XP120	..	o	..	..	3.5/5	4/5	Jan 2017	US$ 229	ebay.com
5.		Fujifilm XP130	..	o	..	..	3.5/5	4/5	Jan 2018	US$ 229	ebay.com
6.		Fujifilm XP140	..	+	..	..	3.5/5	4/5	Feb 2019	US$ 229	ebay.com
7.		Nikon W300	..	+	..	..	4/5	4/5	May 2017	US$ 389	ebay.com
8.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	US$ 1 999	ebay.com
9.		Pentax WG-8	..	..	..	..	..	..	Jun 2024	US$ 399	amazon.com
10.		Pentax WG-1000	..	..	..	..	..	..	Jun 2024	US$ 229	amazon.com
11.		Ricoh WG-60	..	..	..	..	..	..	Oct 2018	US$ 279	ebay.com
12.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	US$ 1 999	ebay.com
13.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	US$ 4 499	ebay.com
14.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	US$ 1 199	ebay.com
15.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	US$ 2 799	ebay.com
16.		Sony RX0	..	..	..	..	3.5/5	4/5	Aug 2017	US$ 699	ebay.com
17.		Sony WX800	..	..	..	..	..	..	Oct 2018	US$ 399	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. Thus, a score needs to be put into the context of the launch date and the launch price 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

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