Olympus TG-6 vs Pentax 645D

The Olympus Tough TG-6 and the Pentax 645D are two digital cameras that were revealed to the public, respectively, in May 2019 and March 2010. The TG-6 is a fixed lens compact, while the 645D is a DSLR. The cameras are based on a 1/2.3-inch (TG-6) and a medium format (645D) sensor. The Olympus has a resolution of 12 megapixels, whereas the Pentax provides 39.5 MP.

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

Headline Specifications

Olympus TG-6		Pentax 645D
Fixed lens compact camera		Digital single lens reflex
25-100mm f/2.0-4.9		Pentax 645 mount lenses
12 MP – 1/2.3" sensor		39.5 MP – Medium Format sensor
4K/30p Video		no Video
ISO 100-12,800		ISO 100-1,600
No viewfinder, LCD framing		Optical viewfinder
3.0" LCD – 1040k dots		3.0" LCD – 921k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
20 shutter flaps per second		1.1 shutter flaps per second
In-body stabilization		Lens stabilization only
Waterproof body (15m)		Weathersealed body
340 shots per battery charge		800 shots per battery charge
113 x 66 x 32 mm, 253 g		156 x 117 x 119 mm, 1480 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus Tough TG-6 and the Pentax 645D? 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 Olympus TG-6 and the Pentax 645D are illustrated 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 TG-6 can be obtained in two different colors (black, red), while the 645D 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 645D is considerably larger (145 percent) than the Olympus TG-6. 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 TG-6 is water-proof up to 15m and can, thus, be used for underwater photography.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the TG-6 has a lens built in, whereas the 645D is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup.

Concerning battery life, the TG-6 gets 340 shots out of its Olympus LI-92B battery, while the 645D can take 800 images on a single charge of its Pentax D-LI90 power pack. The power pack in the TG-6 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.		Olympus TG-6	113 mm	66 mm	32 mm	253 g	340	Y	May 2019	449	ebay.com
2.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
3.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	4,999	ebay.com
4.		Canon 1D X	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	6,799	ebay.com
5.		Canon SX740	110 mm	64 mm	40 mm	299 g	265	n	Jul 2018	399	amazon.com
6.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
7.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
8.		Nikon W300	112 mm	66 mm	29 mm	231 g	280	Y	May 2017	389	ebay.com
9.		Olympus E-PM1	110 mm	64 mm	34 mm	265 g	330	n	Jun 2011	499	ebay.com
10.		Olympus TG-4	112 mm	66 mm	31 mm	247 g	380	Y	Apr 2015	379	ebay.com
11.		Olympus TG-5	113 mm	66 mm	32 mm	250 g	340	Y	May 2017	449	ebay.com
12.		Olympus XZ-1	111 mm	65 mm	42 mm	275 g	320	n	Jan 2011	499	ebay.com
13.		OM System TG-7	114 mm	66 mm	33 mm	249 g	330	Y	Sep 2023	549	amazon.com
14.		Panasonic TS7	117 mm	76 mm	37 mm	319 g	300	Y	May 2018	449	ebay.com
15.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
16.		Ricoh WG-6	118 mm	66 mm	33 mm	246 g	340	Y	Feb 2019	399	amazon.com
17.		Sony HX99	102 mm	58 mm	36 mm	242 g	370	n	Aug 2018	449	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The TG-6 was launched at a lower price than the 645D, 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.

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. 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 Olympus TG-6 features a 1/2.3-inch sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 5086 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 5.6 and 0.79. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.

With 39.5MP, the 645D offers a higher resolution than the TG-6 (12MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 1.53μm for the TG-6) due to its larger sensor. However, the TG-6 is a much more recent model (by 9 years and 2 months) than the 645D, 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 645D has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Pentax 645D implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645D for good quality output (200 dots per inch) amounts to 36.3 x 27.2 inches or 92.3 x 69.1 cm, for very good quality (250 dpi) 29.1 x 21.8 inches or 73.8 x 55.3 cm, and for excellent quality (300 dpi) 24.2 x 18.1 inches or 61.5 x 46.1 cm. The corresponding values for the Olympus TG-6 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 Olympus Tough TG-6 has a native sensitivity range from ISO 100 to ISO 12800. The corresponding ISO settings for the Pentax 645D are ISO 100 to ISO 1600 (no boost).

In terms of underlying technology, the TG-6 is build around a BSI-CMOS sensor, while the 645D uses a CCD 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 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.		Olympus TG-6	1/2.3	12.0	4000	3000	4K/30p	20.7	12.2	1127	52
2.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
3.		Canon 1D Mark IV	APS-H	16.0	4896	3264	1080/30p	22.8	12.0	1320	74
4.		Canon 1D X	Full Frame	17.9	5184	3456	1080/30p	23.8	11.8	2786	82
5.		Canon SX740	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1050	51
6.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
7.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
8.		Nikon W300	1/2.3	15.9	4608	3456	4K/30p	20.5	12.0	938	50
9.		Olympus E-PM1	Four Thirds	12.2	4032	3024	1080/60i	21.0	10.3	499	52
10.		Olympus TG-4	1/2.3	15.9	4608	3456	1080/30p	20.2	11.6	737	47
11.		Olympus TG-5	1/2.3	12.0	4000	3000	4K/30p	20.5	11.9	934	50
12.		Olympus XZ-1	1/1.7	10.1	3664	2752	720/30p	18.8	10.4	117	34
13.		OM System TG-7	1/2.3	12.0	4000	3000	4K/30p	20.9	12.7	1553	54
14.		Panasonic TS7	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1028	51
15.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
16.		Ricoh WG-6	1/2.3	20.2	5184	3888	4K/30p	20.7	12.2	1104	52
17.		Sony HX99	1/2.3	18.0	4896	3672	4K/30p	20.6	12.1	1058	51
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 also of capturing video footage. The TG-6 indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the TG-6 can use is 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the 645D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the TG-6 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Olympus TG-6, the Pentax 645D, 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.		Olympus TG-6	none	n	3.0 / 1040	fixed	n	1/2000s	20.0/s	Y	Y
2.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
3.		Canon 1D Mark IV	optical	Y	3.0 / 920	fixed	n	1/8000s	10.0/s	n	n
4.		Canon 1D X	optical	Y	3.2 / 1040	fixed	n	1/8000s	14.0/s	n	n
5.		Canon SX740	none	n	3.0 / 922	tilting	n	1/3200s	10.0/s	Y	Y
6.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
7.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
8.		Nikon W300	none	n	3.0 / 921	fixed	n	1/4000s	7.0/s	Y	Y
9.		Olympus E-PM1	optional	n	3.0 / 460	fixed	n	1/4000s	5.5/s	n	Y
10.		Olympus TG-4	none	n	3.0 / 460	fixed	n	1/2000s	5.0/s	Y	Y
11.		Olympus TG-5	none	n	3.0 / 460	fixed	n	1/2000s	20.0/s	Y	Y
12.		Olympus XZ-1	optional	n	3.0 / 614	fixed	n	1/2000s	2.0/s	Y	Y
13.		OM System TG-7	none	n	3.0 / 1040	fixed	n	1/2000s	20.0/s	Y	Y
14.		Panasonic TS7	1170	n	3.0 / 1040	fixed	n	1/1300s	10.0/s	Y	Y
15.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
16.		Ricoh WG-6	none	n	3.0 / 1040	fixed	n	1/4000s	1.0/s	Y	n
17.		Sony HX99	638	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 difference between the cameras concerns the presence of an on-board flash. The TG-6 has one, while the 645D does not. While the built-in flash of the TG-6 is not very powerful, it can at times be useful as a fill-in light.

The Olympus TG-6 and the Pentax 645D 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 TG-6 and the 645D write their files to SDXC cards. The 645D features dual card slots, which can be very useful in case a memory card fails. In contrast, the TG-6 only has one slot. The TG-6 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the 645D 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 Olympus Tough TG-6 and Pentax 645D 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.		Olympus TG-6	-	stereo / mono	-	-	micro	2.0	Y	-	-
2.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-
3.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
4.		Canon 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
5.		Canon SX740	-	stereo / mono	-	-	micro	2.0	Y	-	Y
6.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
7.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
8.		Nikon W300	-	stereo / mono	-	-	micro	2.0	Y	-	Y
9.		Olympus E-PM1	Y	stereo / mono	-	-	mini	2.0	-	-	-
10.		Olympus TG-4	-	stereo / mono	-	-	micro	2.0	Y	-	-
11.		Olympus TG-5	-	stereo / mono	-	-	micro	2.0	Y	-	-
12.		Olympus XZ-1	Y	mono / -	-	-	mini	2.0	-	-	-
13.		OM System TG-7	-	stereo / mono	-	-	micro	2.0	Y	-	-
14.		Panasonic TS7	-	stereo / mono	-	-	micro	2.0	Y	-	-
15.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
16.		Ricoh WG-6	-	mono / mono	-	-	micro	3.0	-	-	-
17.		Sony HX99	-	stereo / mono	-	-	micro	2.0	Y	Y	Y

It is notable that the TG-6 offers wifi support, while the 645D does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Studio photographers will appreciate that the Pentax 645D (unlike the TG-6) 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 TG-6 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the TG-6 and the 645D have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the TG-6 was followed by the OM System TG-7. Further information on the features and operation of the TG-6 and 645D can be found, respectively, in the Olympus TG-6 Manual (free pdf) or the online Pentax 645D Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Olympus TG-6 and the Pentax 645D? Which camera is better? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Olympus Tough TG-6:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Broader imaging potential: Can record not only still images but also 4K/30p movies.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
• Faster burst: Shoots at higher frequency (20 vs 1.1 flaps/sec) to capture the decisive moment.
• Ready to shoot: Comes with a built-in lens, while the 645D requires a separate lens.
• More compact: Is smaller (113x66mm vs 156x117mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the 645D).
• Easier travel charging: Can be conveniently charged via its USB port.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Water-proof: Is rugged and sealed and can thus be used for underwater photography (up to 15m).
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 9 years and 2 months of technical progress since the 645D launch.

Arguments in favor of the Pentax 645D:

• More detail: Has more megapixels (39.5 vs 12MP), which boosts linear resolution by 82%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• 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.
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
• More flexible: Makes it possible to change lenses and thus to use specialty optics.
• Longer lasting: Gets more shots (800 versus 340) out of a single battery charge.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More heavily discounted: Has been around for much longer (launched in March 2010).

If the count of individual advantages (bullet points above) is taken as a guide, the TG-6 comes out slightly ahead of the 645D (16 : 15 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 Olympus TG-6 and the Pentax 645D 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 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 TG-6 or the 645D. 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 why hands-on reviews by experts are important. 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.		Olympus TG-6	4/5	+ +	4.5/5	76/100	4/5	4/5	May 2019	449	ebay.com
2.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
3.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	4,999	ebay.com
4.		Canon 1D X	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	6,799	ebay.com
5.		Canon SX740	..	+	3.5/5	..	4/5	4/5	Jul 2018	399	amazon.com
6.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
7.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
8.		Nikon W300	..	+	..	..	4/5	4/5	May 2017	389	ebay.com
9.		Olympus E-PM1	..	86/100	..	71/100	4.5/5	4.5/5	Jun 2011	499	ebay.com
10.		Olympus TG-4	..	+	..	79/100	4/5	4/5	Apr 2015	379	ebay.com
11.		Olympus TG-5	..	+ +	4.5/5	..	4/5	4/5	May 2017	449	ebay.com
12.		Olympus XZ-1	4/5	..	..	74/100	4.5/5	4.5/5	Jan 2011	499	ebay.com
13.		OM System TG-7	4/5	..	4.5/5	..	4/5	4/5	Sep 2023	549	amazon.com
14.		Panasonic TS7	..	+	..	..	..	3.5/5	May 2018	449	ebay.com
15.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
16.		Ricoh WG-6	..	..	..	..	3.5/5	3.5/5	Feb 2019	399	amazon.com
17.		Sony HX99	..	..	..	..	4/5	4.5/5	Aug 2018	449	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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Other camera comparisons

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