Panasonic S5 vs Pentax K-3 III

The Panasonic Lumix DC-S5 and the Pentax K-3 III are two enthusiast cameras that were revealed to the public, respectively, in September 2020 and March 2021. The S5 is a mirrorless interchangeable lens camera, while the K-3 III is a DSLR. The cameras are based on a full frame (S5) and an APS-C (K-3 III) sensor. The Panasonic has a resolution of 24 megapixels, whereas the Pentax provides 25.6 MP.

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

Headline Specifications

Panasonic S5		Pentax K-3 III
Mirrorless system camera		Digital single lens reflex
Leica L mount lenses		Pentax K mount lenses
24 MP – Full Frame sensor		25.6 MP – APS-C sensor
4K/60p Video		4K/30p Video
ISO 100-51,200 (50 - 204,800)		ISO 100-160,000
Electronic viewfinder (2360k dots)		Optical viewfinder
3.0" LCD – 1840k dots		3.2" LCD – 1620k dots
Swivel touchscreen		Fixed touchscreen
7 shutter flaps per second		12 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
440 shots per battery charge		800 shots per battery charge
133 x 98 x 82 mm, 714 g		135 x 104 x 74 mm, 820 g

Check S5 price at
amazon.com
Check K-3 III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DC-S5 and the Pentax K-3 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 Panasonic S5 and the Pentax K-3 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 measures are rounded to the nearest millimeter.

The K-3 III can be obtained in two different colors (black, silver), while the S5 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 Pentax K-3 III is notably larger (8 percent) than the Panasonic S5. Moreover, the K-3 III is markedly heavier (15 percent) than the S5. 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.

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.

Concerning battery life, the S5 gets 440 shots out of its Panasonic DMW-BLK22 battery, while the K-3 III can take 800 images on a single charge of its Pentax D-LI90 power pack. The power pack in the S5 can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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.		Panasonic S5	133 mm	98 mm	82 mm	714 g	440	Y	Sep 2020	1,999	amazon.com
2.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
3.		Canon R6	138 mm	98 mm	88 mm	680 g	360	Y	Jul 2020	2,499	amazon.com
4.		Fujifilm X-T4	135 mm	93 mm	64 mm	607 g	500	Y	Feb 2020	1,699	ebay.com
5.		Nikon Z6 II	134 mm	101 mm	70 mm	705 g	410	Y	Oct 2020	1,999	amazon.com
6.		Panasonic G9	137 mm	97 mm	92 mm	658 g	400	Y	Nov 2017	1,699	ebay.com
7.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	1,999	ebay.com
8.		Panasonic GH5 II	139 mm	98 mm	87 mm	727 g	400	Y	May 2021	1,699	amazon.com
9.		Panasonic S1	149 mm	110 mm	97 mm	1017 g	400	Y	Feb 2019	2,499	amazon.com
10.		Panasonic S1H	151 mm	114 mm	110 mm	1052 g	400	Y	May 2019	3,999	amazon.com
11.		Panasonic S5 II	134 mm	102 mm	90 mm	740 g	370	Y	Jan 2023	1,999	amazon.com
12.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
13.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
14.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
15.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
16.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	1,799	amazon.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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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 size of the imaging sensor is a crucial determinant 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Panasonic S5 features a full frame sensor and the Pentax K-3 III an APS-C sensor. The sensor area in the K-3 III is 57 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the K-3 III offers a slightly higher resolution of 25.6 megapixels, compared with 24 MP of the S5. 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 3.76μm versus 5.94μm for the S5). However, it should be noted that the K-3 III is a somewhat more recent model (by 6 months) than the S5, and its sensor might have benefitted from technological advances during this time that partly offset its pixel-size disadvantage. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

Both cameras have the capacity to capture high quality composite images by combining multiple shots after shifting the sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

The Panasonic Lumix DC-S5 has a native sensitivity range from ISO 100 to ISO 51200, which can be extended to ISO 50-204800. The corresponding ISO settings for the Pentax K-3 III are ISO 100 to ISO 160000 (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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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"). 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 S5	Full Frame	24.0	6000	4000	4K/60p	25.1	14.5	2697	94
2.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
3.		Canon R6	Full Frame	20.0	5472	3648	4k/60p	24.2	14.3	3394	90
4.		Fujifilm X-T4	APS-C	26.0	6240	4160	4K/60p	24.1	13.6	1995	84
5.		Nikon Z6 II	Full Frame	24.3	6048	4024	4K/60p	25.0	14.4	3303	94
6.		Panasonic G9	Four Thirds	20.2	5184	3888	4K/60p	23.1	12.8	1138	74
7.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
8.		Panasonic GH5 II	Four Thirds	20.2	5184	3888	4K/60p	23.7	13.1	1136	79
9.		Panasonic S1	Full Frame	24.0	6000	4000	4K/60p	25.2	14.5	3333	95
10.		Panasonic S1H	Full Frame	24.0	6000	4000	6K/30p	25.2	14.2	2805	94
11.		Panasonic S5 II	Full Frame	24.0	6000	4000	6K/30p	25.4	14.6	3158	96
12.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
13.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
14.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
15.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
16.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the S5 provides a higher frame rate than the K-3 III. It can shoot video footage at 4K/60p, while the Pentax is limited to 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the S5 has an electronic viewfinder (2360k dots), while the K-3 III 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the S5 has a higher magnification than the one of the K-3 III (0.74x vs 0.70x), 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 S5, the Pentax K-3 III, 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 S5	2360	n	3.0 / 1840	swivel	Y	1/8000s	7.0/s	n	Y
2.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
3.		Canon R6	3690	n	3.0 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
4.		Fujifilm X-T4	3690	n	3.0 / 1620	swivel	Y	1/8000s	15.0/s	n	Y
5.		Nikon Z6 II	3690	Y	3.2 / 2100	tilting	Y	1/8000s	14.0/s	n	Y
6.		Panasonic G9	3680	Y	3.0 / 1040	swivel	Y	1/8000s	20.0/s	n	Y
7.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
8.		Panasonic GH5 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	12.0/s	n	Y
9.		Panasonic S1	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
10.		Panasonic S1H	5760	Y	3.2 / 2330	swivel	Y	1/8000s	9.0/s	n	Y
11.		Panasonic S5 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	9.0/s	n	Y
12.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
13.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
14.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
15.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
16.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the K-3 III, but is missing on the S5 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 S5 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 Panasonic S5 and the Pentax K-3 III both have 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 S5 and the K-3 III write their files to SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. Both the S5 and the K-3 III support UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s) on the first slot and UHS-I cards (104 MB/s) on the second one.

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 DC-S5 and Pentax K-3 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.		Panasonic S5	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
2.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
3.		Canon R6	Y	mono / mono	Y	Y	micro	3.2	Y	-	Y
4.		Fujifilm X-T4	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
5.		Nikon Z6 II	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
6.		Panasonic G9	Y	stereo / mono	Y	Y	full	3.0	Y	-	Y
7.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
8.		Panasonic GH5 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
9.		Panasonic S1	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
10.		Panasonic S1H	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
11.		Panasonic S5 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
12.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
13.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
14.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
15.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
16.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y

Studio photographers will appreciate that the Pentax K-3 III (unlike the S5) 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 K-3 III has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the S5 and the K-3 III are recent models that are part of the current product line-up. The K-3 III replaced the earlier Pentax K-3 II, while the S5 does not have a direct predecessor. Further information on the features and operation of the S5 and K-3 III can be found, respectively, in the Panasonic S5 Manual (free pdf) or the online Pentax K-3 III Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Panasonic S5 and the Pentax K-3 III? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Panasonic Lumix DC-S5:

• 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 (4K/60p versus 4K/30p).
• More framing info: Has an electronic viewfinder that displays shooting data.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.74x vs 0.70x).
• More detailed LCD: Has a higher resolution rear screen (1840k vs 1620k dots).
• More flexible LCD: Has a swivel 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.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Less heavy: Is lighter (by 106g or 13 percent) and hence easier to carry around.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• More heavily discounted: Has been on the market for longer (launched in September 2020).

Reasons to prefer the Pentax K-3 III:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• 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.
• Faster burst: Shoots at higher frequency (12 vs 7 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (800 versus 440) out of a single battery charge.
• 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.
• More modern: Was introduced somewhat (6 months) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the S5 is the clear winner of the match-up (15 : 8 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Panasonic S5 and the Pentax K-3 III 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the S5 or the K-3 III. 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 where reviews by experts come in. The following table reports the overall ratings of the cameras as published by some of the major 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.		Panasonic S5	4.5/5	+ +	4.5/5	88/100	4.5/5	4.5/5	Sep 2020	1,999	amazon.com
2.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
3.		Canon R6	5/5	+ +	4/5	90/100	4.5/5	5/5	Jul 2020	2,499	amazon.com
4.		Fujifilm X-T4	5/5	+ +	5/5	88/100	5/5	5/5	Feb 2020	1,699	ebay.com
5.		Nikon Z6 II	4.5/5	..	4/5	89/100	4.5/5	4.5/5	Oct 2020	1,999	amazon.com
6.		Panasonic G9	..	+ +	5/5	85/100	5/5	5/5	Nov 2017	1,699	ebay.com
7.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	1,999	ebay.com
8.		Panasonic GH5 II	4.5/5	..	4.5/5	85/100	4.5/5	5/5	May 2021	1,699	amazon.com
9.		Panasonic S1	4.5/5	+ +	4.5/5	88/100	4.5/5	4/5	Feb 2019	2,499	amazon.com
10.		Panasonic S1H	..	..	4/5	90/100	..	..	May 2019	3,999	amazon.com
11.		Panasonic S5 II	4.5/5	+ +	5/5	90/100	4.5/5	5/5	Jan 2023	1,999	amazon.com
12.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
13.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
14.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
15.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
16.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	1,799	amazon.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. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.

Check S5 price at
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Check K-3 III price at
amazon.com

Other camera comparisons

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