Olympus XZ-2 vs Pentax 645D

The Olympus XZ-2 and the Pentax 645D are two digital cameras that were revealed to the public, respectively, in September 2012 and March 2010. The XZ-2 is a fixed lens compact, while the 645D is a DSLR. The cameras are based on a 1/1.7-inch (XZ-2) and a medium format (645D) sensor. The Olympus has a resolution of 11.8 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 XZ-2		Pentax 645D
Fixed lens compact camera		Digital single lens reflex
28-112mm f/1.8-2.5		Pentax 645 mount lenses
11.8 MP – 1/1.7" sensor		39.5 MP – Medium Format sensor
1080/30p Video		no Video
ISO 100-12,800		ISO 100-1,600
Viewfinder optional		Optical viewfinder
3.0" LCD – 920k dots		3.0" LCD – 921k dots
Tilting touchscreen		Fixed screen (not touch-sensitive)
5 shutter flaps per second		1.1 shutter flaps per second
In-body stabilization		Lens stabilization only
not weather sealed		Weathersealed body
340 shots per battery charge		800 shots per battery charge
113 x 65 x 48 mm, 346 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 XZ-2 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 side-by-side display below illustrates the physical size and weight of the Olympus XZ-2 and the Pentax 645D. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth dimensions are rounded to the nearest millimeter.

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 (148 percent) than the Olympus XZ-2. It is noteworthy in this context that the 645D is splash and dust-proof, while the XZ-2 does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the XZ-2 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.

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 XZ-2	113 mm	65 mm	48 mm	346 g	340	n	Sep 2012	599	ebay.com
2.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
3.		Canon G16	109 mm	76 mm	40 mm	356 g	360	n	Aug 2013	549	ebay.com
4.		Canon G15	107 mm	76 mm	40 mm	352 g	350	n	Sep 2012	499	ebay.com
5.		Canon 1D X	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	6,799	ebay.com
6.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	4,999	ebay.com
7.		Fujifilm X10	117 mm	70 mm	57 mm	350 g	270	n	Sep 2011	599	ebay.com
8.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
9.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
10.		Olympus Stylus 1	116 mm	87 mm	57 mm	402 g	410	n	Oct 2013	699	ebay.com
11.		Olympus E-P3	122 mm	69 mm	34 mm	369 g	330	n	Jun 2011	799	ebay.com
12.		Olympus E-PL2	114 mm	72 mm	42 mm	362 g	280	n	Jan 2011	599	ebay.com
13.		Olympus E-PL3	110 mm	64 mm	37 mm	313 g	300	n	Jun 2011	599	ebay.com
14.		Olympus XZ-1	111 mm	65 mm	42 mm	275 g	320	n	Jan 2011	499	ebay.com
15.		Panasonic LX7	111 mm	68 mm	46 mm	298 g	330	n	Jul 2012	499	ebay.com
16.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
17.		Pentax MX-1	122 mm	61 mm	51 mm	391 g	290	n	Jan 2013	499	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 obviously take relative prices into account. 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 XZ-2 was launched at a lower price than the 645D, despite having a lens built in. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 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. 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 associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Olympus XZ-2 features a 1/1.7-inch sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 3277 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 4.4 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 XZ-2 (11.8MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 1.91μm for the XZ-2) due to its larger sensor. However, the XZ-2 is a much more recent model (by 2 years and 6 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 XZ-2 are 19.8 x 14.9 inches or 50.4 x 37.8 cm for good quality, 15.9 x 11.9 inches or 40.3 x 30.2 cm for very good quality, and 13.2 x 9.9 inches or 33.6 x 25.2 cm for excellent quality prints.

The Olympus XZ-2 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 XZ-2 is build around a 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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"). Of the two cameras under consideration, the 645D offers substantially better image quality than the XZ-2 (overall score 33 points higher). The advantage is based on 4.2 bits higher color depth, 1.3 EV in additional dynamic range, and 2.5 stops in additional low light sensitivity. 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 XZ-2	1/1.7	11.8	3968	2976	1080/30p	20.4	11.3	216	49
2.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
3.		Canon G16	1/1.7	12.0	4000	3000	1080/60p	21.0	11.7	230	54
4.		Canon G15	1/1.7	12.0	4000	3000	1080/24p	19.9	11.5	165	46
5.		Canon 1D X	Full Frame	17.9	5184	3456	1080/30p	23.8	11.8	2786	82
6.		Canon 1D Mark IV	APS-H	16.0	4896	3264	1080/30p	22.8	12.0	1320	74
7.		Fujifilm X10	2/3	12.0	4000	3000	1080/30p	20.5	11.3	245	50
8.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
9.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
10.		Olympus Stylus 1	1/1.7	11.8	3968	2976	1080/30p	20.7	11.6	179	51
11.		Olympus E-P3	Four Thirds	12.2	4032	3024	1080/60i	20.8	10.1	536	51
12.		Olympus E-PL2	Four Thirds	12.2	4032	3024	720/30p	21.4	10.2	573	55
13.		Olympus E-PL3	Four Thirds	12.2	4032	3024	1080/60i	20.9	10.3	499	52
14.		Olympus XZ-1	1/1.7	10.1	3664	2752	720/30p	18.8	10.4	117	34
15.		Panasonic LX7	1/1.7	10.0	3648	2736	1080/60p	20.7	11.7	147	50
16.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
17.		Pentax MX-1	1/1.7	12.0	4000	3000	1080/30p	20.4	11.3	208	49

Many modern cameras cannot only take still pictures, but also record videos. The XZ-2 indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the XZ-2 can use is 1080/30p.

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 XZ-2 relies on live view and the rear LCD for framing. That said, the XZ-2 can be equipped with an optional viewfinder – the VF-2. The adjacent table lists some of the other core features of the Olympus XZ-2 and Pentax 645D 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 XZ-2	optional	n	3.0 / 920	tilting	Y	1/2000s	5.0/s	Y	Y
2.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
3.		Canon G16	optical	n	3.0 / 922	fixed	n	1/4000s	2.2/s	Y	Y
4.		Canon G15	optical	n	3.0 / 922	fixed	n	1/4000s	2.1/s	Y	Y
5.		Canon 1D X	optical	Y	3.2 / 1040	fixed	n	1/8000s	14.0/s	n	n
6.		Canon 1D Mark IV	optical	Y	3.0 / 920	fixed	n	1/8000s	10.0/s	n	n
7.		Fujifilm X10	optical	n	2.8 / 460	fixed	n	1/4000s	10.0/s	Y	Y
8.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
9.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
10.		Olympus Stylus 1	1440	n	3.0 / 1040	tilting	Y	1/2000s	7.0/s	Y	Y
11.		Olympus E-P3	optional	n	3.0 / 614	fixed	Y	1/4000s	3.0/s	Y	Y
12.		Olympus E-PL2	optional	n	3.0 / 460	fixed	n	1/4000s	3.0/s	Y	Y
13.		Olympus E-PL3	optional	n	3.0 / 460	tilting	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.		Panasonic LX7	optional	n	3.0 / 920	fixed	n	1/4000s	11.0/s	Y	Y
16.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
17.		Pentax MX-1	none	n	3.0 / 920	tilting	n	1/8000s	1.0/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 XZ-2 has one, while the 645D does not. While the built-in flash of the XZ-2 is not very powerful, it can at times be useful as a fill-in light.

The Olympus XZ-2 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 XZ-2 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 XZ-2 only has one slot.

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 XZ-2 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 XZ-2	Y	stereo / mono	-	-	mini	2.0	-	-	-
2.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-
3.		Canon G16	Y	stereo / mono	-	-	mini	2.0	Y	-	-
4.		Canon G15	Y	stereo / mono	-	-	mini	2.0	-	-	-
5.		Canon 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
6.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
7.		Fujifilm X10	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
9.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
10.		Olympus Stylus 1	Y	stereo / mono	-	-	micro	2.0	Y	-	-
11.		Olympus E-P3	Y	stereo / -	-	-	mini	2.0	-	-	-
12.		Olympus E-PL2	Y	stereo / -	-	-	mini	2.0	-	-	-
13.		Olympus E-PL3	Y	stereo / -	-	-	mini	2.0	-	-	-
14.		Olympus XZ-1	Y	mono / -	-	-	mini	2.0	-	-	-
15.		Panasonic LX7	Y	stereo / mono	-	-	mini	2.0	-	-	-
16.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
17.		Pentax MX-1	-	stereo / mono	-	-	mini	2.0	-	-	-

Studio photographers will appreciate that the Pentax 645D (unlike the XZ-2) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the XZ-2 and the 645D have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the XZ-2 does not have a direct successor. Further information on the features and operation of the XZ-2 and 645D can be found, respectively, in the Olympus XZ-2 Manual (free pdf) or the online Pentax 645D Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Olympus XZ-2 or the Pentax 645D – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.

Advantages of the Olympus XZ-2:

• 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 1080/30p movies.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Faster burst: Shoots at higher frequency (5 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 (113x65mm 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).
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 2 years and 6 months of technical progress since the 645D launch.

Arguments in favor of the Pentax 645D:

• More detail: Has more megapixels (39.5 vs 11.8MP), which boosts linear resolution by 83%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores substantially higher (33 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (4.2 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (2.5 stops ISO advantage).
• 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 sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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 645D emerges as the winner of the match-up (15 : 12 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 Olympus XZ-2 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 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 XZ-2 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 expert reviews are important. 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.		Olympus XZ-2	4/5	+	..	..	4.5/5	4.5/5	Sep 2012	599	ebay.com
2.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
3.		Canon G16	4/5	+	..	..	4.5/5	4.5/5	Aug 2013	549	ebay.com
4.		Canon G15	4/5	+	..	76/100	4.5/5	4.5/5	Sep 2012	499	ebay.com
5.		Canon 1D X	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	6,799	ebay.com
6.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	4,999	ebay.com
7.		Fujifilm X10	..	..	..	76/100	4/5	4.5/5	Sep 2011	599	ebay.com
8.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
9.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
10.		Olympus Stylus 1	..	+ +	..	..	4.5/5	4.5/5	Oct 2013	699	ebay.com
11.		Olympus E-P3	..	83/100	..	74/100	4.5/5	4.5/5	Jun 2011	799	ebay.com
12.		Olympus E-PL2	3/5	83/100	..	71/100	4.5/5	4.5/5	Jan 2011	599	ebay.com
13.		Olympus E-PL3	3/5	+ +	..	72/100	4.5/5	4/5	Jun 2011	599	ebay.com
14.		Olympus XZ-1	4/5	..	..	74/100	4.5/5	4.5/5	Jan 2011	499	ebay.com
15.		Panasonic LX7	3/5	+ +	..	75/100	4/5	4.5/5	Jul 2012	499	ebay.com
16.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
17.		Pentax MX-1	3/5	..	..	74/100	4/5	4/5	Jan 2013	499	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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date 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

Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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