Olympus TG-5 vs Pentax 645Z

The Olympus Tough TG-5 and the Pentax 645Z are two digital cameras that were revealed to the public, respectively, in May 2017 and April 2014. The TG-5 is a fixed lens compact, while the 645Z is a DSLR. The cameras are based on a 1/2.3-inch (TG-5) and a medium format (645Z) sensor. The Olympus has a resolution of 12 megapixels, whereas the Pentax provides 51.1 MP.

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

Headline Specifications

Olympus TG-5		Pentax 645Z
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		51.1 MP – Medium Format sensor
4K/30p Video		1080/60i Video
ISO 100-12,800		ISO 100-204,800
No viewfinder, LCD framing		Optical viewfinder
3.0" LCD – 460k dots		3.2" LCD – 1037k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
20 shutter flaps per second		3 shutter flaps per second
In-body stabilization		Lens stabilization only
Waterproof body (15m)		Weathersealed body
340 shots per battery charge		650 shots per battery charge
113 x 66 x 32 mm, 250 g		156 x 117 x 123 mm, 1550 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus Tough TG-5 and the Pentax 645Z? 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-5 and the Pentax 645Z 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 dimensions are rounded to the nearest millimeter.

The TG-5 can be obtained in two different colors (black, red), while the 645Z 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 645Z is considerably larger (145 percent) than the Olympus TG-5. 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-5 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-5 has a lens built in, whereas the 645Z 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-5 gets 340 shots out of its Olympus LI-92B battery, while the 645Z can take 650 images on a single charge of its Pentax D-LI90 power pack. The power pack in the TG-5 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 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 (USD)	Street Price
1.		Olympus TG-5	113 mm	66 mm	32 mm	250 g	340	Y	May 2017	449	ebay.com
2.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
3.		Canon SX740	110 mm	64 mm	40 mm	299 g	265	n	Jul 2018	399	amazon.com
4.		Canon SX730	110 mm	64 mm	40 mm	300 g	250	n	Apr 2017	399	ebay.com
5.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
6.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
7.		Fujifilm XP130	110 mm	71 mm	28 mm	207 g	240	Y	Jan 2018	229	ebay.com
8.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	8,995	ebay.com
9.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
10.		Nikon W300	112 mm	66 mm	29 mm	231 g	280	Y	May 2017	389	ebay.com
11.		Olympus TG-6	113 mm	66 mm	32 mm	253 g	340	Y	May 2019	449	ebay.com
12.		Olympus TG-4	112 mm	66 mm	31 mm	247 g	380	Y	Apr 2015	379	ebay.com
13.		Olympus E-PM1	110 mm	64 mm	34 mm	265 g	330	n	Jun 2011	499	ebay.com
14.		Olympus XZ-1	111 mm	65 mm	42 mm	275 g	320	n	Jan 2011	499	ebay.com
15.		OM System TG-7	114 mm	66 mm	33 mm	249 g	330	Y	Sep 2023	549	amazon.com
16.		Panasonic TS7	117 mm	76 mm	37 mm	319 g	300	Y	May 2018	449	ebay.com
17.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The TG-5 was launched at a lower price than the 645Z, 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. 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Olympus TG-5 features a 1/2.3-inch sensor and the Pentax 645Z a medium format sensor. The sensor area in the 645Z is 5032 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 51.1MP, the 645Z offers a higher resolution than the TG-5 (12MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 1.53μm for the TG-5) due to its larger sensor. However, the TG-5 is a much more recent model (by 3 years and 1 month) than the 645Z, 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 645Z has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Pentax 645Z implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645Z for good quality output (200 dots per inch) amounts to 41.3 x 31 inches or 104.9 x 78.6 cm, for very good quality (250 dpi) 33 x 24.8 inches or 83.9 x 62.9 cm, and for excellent quality (300 dpi) 27.5 x 20.6 inches or 69.9 x 52.4 cm. The corresponding values for the Olympus TG-5 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-5 has a native sensitivity range from ISO 100 to ISO 12800. The corresponding ISO settings for the Pentax 645Z are ISO 100 to ISO 204800 (no boost).

In terms of underlying technology, the TG-5 is build around a BSI-CMOS sensor, while the 645Z 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 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.		Olympus TG-5	1/2.3	12.0	4000	3000	4K/30p	20.5	11.9	934	50
2.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
3.		Canon SX740	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1050	51
4.		Canon SX730	1/2.3	20.2	5184	3888	1080/60p	20.5	11.9	924	50
5.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
6.		Canon 5DS R	Full Frame	50.3	8688	5792	1080/30p	24.6	12.4	2308	86
7.		Fujifilm XP130	1/2.3	15.9	4608	3456	1080/60p	20.6	12.1	1000	51
8.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
9.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
10.		Nikon W300	1/2.3	15.9	4608	3456	4K/30p	20.5	12.0	938	50
11.		Olympus TG-6	1/2.3	12.0	4000	3000	4K/30p	20.7	12.2	1127	52
12.		Olympus TG-4	1/2.3	15.9	4608	3456	1080/30p	20.2	11.6	737	47
13.		Olympus E-PM1	Four Thirds	12.2	4032	3024	1080/60i	21.0	10.3	499	52
14.		Olympus XZ-1	1/1.7	10.1	3664	2752	720/30p	18.8	10.4	117	34
15.		OM System TG-7	1/2.3	12.0	4000	3000	4K/30p	20.9	12.7	1553	54
16.		Panasonic TS7	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1028	51
17.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
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. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the TG-5 provides a higher video resolution than the 645Z. It can shoot video footage at 4K/30p, while the Pentax is limited to 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the 645Z has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the TG-5 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Olympus TG-5 and Pentax 645Z 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.		Olympus TG-5	none	n	3.0 / 460	fixed	n	1/2000s	20.0/s	Y	Y
2.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
3.		Canon SX740	none	n	3.0 / 922	tilting	n	1/3200s	10.0/s	Y	Y
4.		Canon SX730	none	n	3.0 / 922	tilting	n	1/3200s	5.9/s	Y	Y
5.		Canon 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
6.		Canon 5DS R	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
7.		Fujifilm XP130	none	n	3.0 / 920	fixed	n	1/2000s	10.0/s	Y	Y
8.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
9.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
10.		Nikon W300	none	n	3.0 / 921	fixed	n	1/4000s	7.0/s	Y	Y
11.		Olympus TG-6	none	n	3.0 / 1040	fixed	n	1/2000s	20.0/s	Y	Y
12.		Olympus TG-4	none	n	3.0 / 460	fixed	n	1/2000s	5.0/s	Y	Y
13.		Olympus E-PM1	optional	n	3.0 / 460	fixed	n	1/4000s	5.5/s	n	Y
14.		Olympus XZ-1	optional	n	3.0 / 614	fixed	n	1/2000s	2.0/s	Y	Y
15.		OM System TG-7	none	n	3.0 / 1040	fixed	n	1/2000s	20.0/s	Y	Y
16.		Panasonic TS7	1170	n	3.0 / 1040	fixed	n	1/1300s	10.0/s	Y	Y
17.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
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-5 has one, while the 645Z does not. While the built-in flash of the TG-5 is not very powerful, it can at times be useful as a fill-in light.

The Olympus TG-5 and the Pentax 645Z 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-5 and the 645Z write their files to SDXC cards. The 645Z features dual card slots, which can be very useful in case a memory card fails. In contrast, the TG-5 only has one slot. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.

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-5 and Pentax 645Z 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-5	-	stereo / mono	-	-	micro	2.0	Y	-	-
2.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
3.		Canon SX740	-	stereo / mono	-	-	micro	2.0	Y	-	Y
4.		Canon SX730	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
5.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
6.		Canon 5DS R	Y	mono / mono	Y	-	mini	3.0	-	-	-
7.		Fujifilm XP130	-	mono / mono	-	-	micro	2.0	Y	-	Y
8.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
9.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
10.		Nikon W300	-	stereo / mono	-	-	micro	2.0	Y	-	Y
11.		Olympus TG-6	-	stereo / mono	-	-	micro	2.0	Y	-	-
12.		Olympus TG-4	-	stereo / mono	-	-	micro	2.0	Y	-	-
13.		Olympus E-PM1	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Olympus XZ-1	Y	mono / -	-	-	mini	2.0	-	-	-
15.		OM System TG-7	-	stereo / mono	-	-	micro	2.0	Y	-	-
16.		Panasonic TS7	-	stereo / mono	-	-	micro	2.0	Y	-	-
17.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-

It is notable that the TG-5 offers wifi support, while the 645Z 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 645Z (unlike the TG-5) 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-5 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the TG-5 and the 645Z have been discontinued, but can regularly be found used on ebay. The TG-5 was replaced by the Olympus TG-6, while the 645Z does not have a direct successor. Further information on the features and operation of the TG-5 and 645Z can be found, respectively, in the Olympus TG-5 Manual (free pdf) or the online Pentax 645Z Manual.

Review summary

So how do things add up? Is there a clear favorite between the Olympus TG-5 and the Pentax 645Z? Which camera is better? The listing below highlights the relative strengths of the two models.

Arguments in favor of the Olympus Tough TG-5:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
• Faster burst: Shoots at higher frequency (20 vs 3 flaps/sec) to capture the decisive moment.
• Ready to shoot: Comes with a built-in lens, while the 645Z 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 645Z).
• 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.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 3 years and 1 month of technical progress since the 645Z launch.

Advantages of the Pentax 645Z:

• More detail: Has more megapixels (51.1 vs 12MP), which boosts linear resolution by 106%.
• 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.
• Better sound: Can connect to an external microphone for higher quality sound recording.
• 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.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1037k vs 460k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• 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 (650 versus 340) out of a single battery charge.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• 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 April 2014).

If the number of relative strengths (bullet points above) is taken as a guide, the 645Z is the clear winner of the contest (20 : 14 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 wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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-5 and the Pentax 645Z 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 technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the TG-5 or the 645Z. 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-5	..	+ +	4.5/5	..	4/5	4/5	May 2017	449	ebay.com
2.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
3.		Canon SX740	..	+	3.5/5	..	4/5	4/5	Jul 2018	399	amazon.com
4.		Canon SX730	..	+	..	..	4/5	4/5	Apr 2017	399	ebay.com
5.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	3,699	ebay.com
6.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	3,699	ebay.com
7.		Fujifilm XP130	..	o	..	..	3.5/5	4/5	Jan 2018	229	ebay.com
8.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	8,995	ebay.com
9.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
10.		Nikon W300	..	+	..	..	4/5	4/5	May 2017	389	ebay.com
11.		Olympus TG-6	4/5	+ +	4.5/5	76/100	4/5	4/5	May 2019	449	ebay.com
12.		Olympus TG-4	..	+	..	79/100	4/5	4/5	Apr 2015	379	ebay.com
13.		Olympus E-PM1	..	86/100	..	71/100	4.5/5	4.5/5	Jun 2011	499	ebay.com
14.		Olympus XZ-1	4/5	..	..	74/100	4.5/5	4.5/5	Jan 2011	499	ebay.com
15.		OM System TG-7	4/5	..	4.5/5	..	4/5	4/5	Sep 2023	549	amazon.com
16.		Panasonic TS7	..	+	..	..	..	3.5/5	May 2018	449	ebay.com
17.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated 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 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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