Fujifilm X-M1 vs Pentax 645D

The Fujifilm X-M1 and the Pentax 645D are two digital cameras that were officially introduced, respectively, in June 2013 and March 2010. The X-M1 is a mirrorless interchangeable lens camera, while the 645D is a DSLR. The cameras are based on an APS-C (X-M1) and a medium format (645D) sensor. The Fujifilm has a resolution of 16 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

Fujifilm X-M1		Pentax 645D
Mirrorless system camera		Digital single lens reflex
Fujifilm X mount lenses		Pentax 645 mount lenses
16 MP – APS-C sensor		39.5 MP – Medium Format sensor
1080/30p Video		no Video
ISO 200-6,400 (100 - 25,600)		ISO 100-1,600
No viewfinder, LCD framing		Optical viewfinder
3.0" LCD – 920k dots		3.0" LCD – 921k dots
Tilting screen (no touchscreen)		Fixed screen (not touch-sensitive)
5.6 shutter flaps per second		1.1 shutter flaps per second
not weather sealed		Weathersealed body
350 shots per battery charge		800 shots per battery charge
117 x 67 x 39 mm, 330 g		156 x 117 x 119 mm, 1480 g

Check X-M1 offers at
ebay.com
Check 645D offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Fujifilm X-M1 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

An illustration of the physical size and weight of the Fujifilm X-M1 and the Pentax 645D is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All width, height and depth measures are rounded to the nearest millimeter.

The X-M1 can be obtained in three different colors (black, silver, brown), 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 (133 percent) than the Fujifilm X-M1. Moreover, the 645D is substantially heavier (348 percent) than the X-M1. It is noteworthy in this context that the 645D is splash and dust-proof, while the X-M1 does not feature any corresponding weather-sealing.

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 X-M1 gets 350 shots out of its Fujifilm NP-W126 battery, while the 645D can take 800 images on a single charge of its Pentax D-LI90 power pack.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Fujifilm X-M1	117 mm	67 mm	39 mm	330 g	350	n	Jun 2013	US$ 699	ebay.com
2.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	US$ 9 995	ebay.com
3.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	US$ 4 999	ebay.com
4.		Canon 1D X	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	US$ 6 799	ebay.com
5.		Fujifilm X-A1	117 mm	67 mm	39 mm	330 g	350	n	Sep 2013	US$ 399	ebay.com
6.		Fujifilm X-A2	117 mm	67 mm	40 mm	350 g	410	n	Jan 2015	US$ 399	ebay.com
7.		Fujifilm X-A10	117 mm	67 mm	40 mm	331 g	410	n	Dec 2016	US$ 399	ebay.com
8.		Fujifilm X-E1	129 mm	75 mm	38 mm	350 g	350	n	Sep 2012	US$ 999	ebay.com
9.		Fujifilm X-E2	129 mm	75 mm	37 mm	350 g	350	n	Oct 2013	US$ 999	ebay.com
10.		Fujifilm X-E2S	129 mm	75 mm	37 mm	350 g	350	n	Jan 2016	US$ 699	ebay.com
11.		Fujifilm X-Pro1	140 mm	82 mm	43 mm	450 g	300	n	Jan 2012	US$ 1 699	ebay.com
12.		Fujifilm X-T10	118 mm	83 mm	41 mm	381 g	350	n	May 2015	US$ 799	ebay.com
13.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	US$ 21 949	ebay.com
14.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	US$ 5 199	ebay.com
15.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	US$ 8 499	ebay.com
16.		Sony NEX-5R	111 mm	59 mm	39 mm	276 g	330	n	Aug 2012	US$ 749	ebay.com
17.		Sony NEX-F3	117 mm	67 mm	42 mm	314 g	470	n	May 2012	US$ 599	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

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 X-M1 was launched at a markedly lower price (by 93 percent) than the 645D, which puts it into a different 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Fujifilm X-M1 features an APS-C sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 295 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 0.79. The sensor in the X-M1 has a native 3:2 aspect ratio, while the one in the 645D offers a 4:3 aspect.

With 39.5MP, the 645D offers a higher resolution than the X-M1 (16MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 4.80μm for the X-M1) due to its larger sensor. However, the X-M1 is a much more recent model (by 3 years and 3 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 neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the 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 Fujifilm X-M1 are 24.5 x 16.3 inches or 62.2 x 41.5 cm for good quality, 19.6 x 13.1 inches or 49.7 x 33.2 cm for very good quality, and 16.3 x 10.9 inches or 41.5 x 27.6 cm for excellent quality prints.

The Fujifilm X-M1 has a native sensitivity range from ISO 200 to ISO 6400, which can be extended to ISO 100-25600. The corresponding ISO settings for the Pentax 645D are ISO 100 to ISO 1600 (no boost).

In terms of underlying technology, the X-M1 is build around a CMOS sensor, while the 645D uses a CCD imager. The X-M1 uses Fujifilm's X-Trans layout of photosites, while the 645D employs the more common Bayer array.

For many cameras, data on sensor performance has been reported by DXO Mark. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. 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.		Fujifilm X-M1	APS-C	16.0	4896	3264	1080/30p	23.4	12.6	1371	76
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.		Fujifilm X-A1	APS-C	16.0	4896	3264	1080/30p	23.4	12.6	1390	76
6.		Fujifilm X-A2	APS-C	16.0	4896	3264	1080/30p	23.6	12.8	1515	79
7.		Fujifilm X-A10	APS-C	16.0	4896	3264	1080/30p	23.9	13.2	1691	81
8.		Fujifilm X-E1	APS-C	16.0	4896	3264	1080/24p	23.2	12.4	1298	75
9.		Fujifilm X-E2	APS-C	16.0	4896	3264	1080/60p	23.4	12.6	1400	77
10.		Fujifilm X-E2S	APS-C	16.0	4896	3264	1080/60p	23.7	13.0	1608	80
11.		Fujifilm X-Pro1	APS-C	16.0	4896	3264	1080/24p	23.1	12.3	1238	74
12.		Fujifilm X-T10	APS-C	16.0	4896	3264	1080/60p	23.7	12.9	1546	79
13.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
14.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
15.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
16.		Sony NEX-5R	APS-C	16.0	4912	3264	1080/60i	23.7	13.1	910	78
17.		Sony NEX-F3	APS-C	16.0	4912	3264	1080/60i	22.7	12.3	1114	73
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 X-M1 indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the X-M1 can use is 1080/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the 645D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the X-M1 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Fujifilm X-M1, 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.		Fujifilm X-M1	none	n	3.0 / 920	tilting	n	1/4000s	5.6/s	Y	n
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.		Fujifilm X-A1	none	n	3.0 / 920	tilting	n	1/4000s	5.6/s	Y	n
6.		Fujifilm X-A2	none	n	3.0 / 920	tilting	n	1/4000s	5.6/s	Y	n
7.		Fujifilm X-A10	none	n	3.0 / 1040	tilting	n	1/4000s	6.0/s	Y	n
8.		Fujifilm X-E1	2360	n	2.8 / 460	fixed	n	1/4000s	6.0/s	Y	n
9.		Fujifilm X-E2	2360	n	3.0 / 1040	fixed	n	1/4000s	7.0/s	Y	n
10.		Fujifilm X-E2S	2360	n	3.0 / 1040	fixed	n	1/4000s	7.0/s	Y	n
11.		Fujifilm X-Pro1	1440	n	3.0 / 1230	fixed	n	1/4000s	6.0/s	n	n
12.		Fujifilm X-T10	2360	n	3.0 / 920	tilting	n	1/4000s	8.0/s	Y	n
13.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
14.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
15.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
16.		Sony NEX-5R	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
17.		Sony NEX-F3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	Y	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 X-M1 has one, while the 645D does not. While the built-in flash of the X-M1 is not very powerful, it can at times be useful as a fill-in light.

The Pentax 645D 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.

Concerning the storage of imaging data, both the X-M1 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 X-M1 only has one slot. The X-M1 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 Fujifilm X-M1 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.		Fujifilm X-M1	Y	stereo / mono	-	-	mini	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.		Fujifilm X-A1	Y	stereo / mono	-	-	mini	2.0	Y	-	-
6.		Fujifilm X-A2	Y	stereo / mono	-	-	mini	2.0	Y	-	-
7.		Fujifilm X-A10	-	stereo / mono	-	-	micro	2.0	Y	-	-
8.		Fujifilm X-E1	Y	stereo / mono	Y	-	mini	2.0	-	-	-
9.		Fujifilm X-E2	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
10.		Fujifilm X-E2S	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
11.		Fujifilm X-Pro1	Y	stereo / mono	-	-	mini	2.0	-	-	-
12.		Fujifilm X-T10	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
13.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
14.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
15.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
16.		Sony NEX-5R	Y	stereo / mono	-	-	mini	2.0	Y	-	-
17.		Sony NEX-F3	Y	stereo / mono	-	-	mini	2.0	-	-	-

It is notable that the X-M1 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 X-M1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the X-M1 and the 645D have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the X-M1 does not have a direct successor. Further information on the features and operation of the X-M1 and 645D can be found, respectively, in the Fujifilm X-M1 Manual (free pdf) or the online Pentax 645D Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Fujifilm X-M1 or the Pentax 645D – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Fujifilm X-M1:

• 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.
• Faster burst: Shoots at higher frequency (5.6 vs 1.1 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (117x67mm vs 156x117mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 1150g or 78 percent) and hence easier to carry around.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• 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 into a lower priced category (93 percent cheaper at launch).
• More modern: Reflects 3 years and 3 months of technical progress since the 645D launch.

Reasons to prefer the Pentax 645D:

• More detail: Has more megapixels (39.5 vs 16MP), which boosts linear resolution by 54%.
• 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.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Gets more shots (800 versus 350) 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 number of relative strengths (bullet points above) is taken as a guide, the 645D emerges as the winner of the match-up (13 : 11 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 Fujifilm X-M1 and the Pentax 645D 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 technical specifications can provide a useful overview of the capabilities of different cameras, it remains incomplete and does no justice, for example, to the way the X-M1 or the 645D perform in practice. 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 expert reviews 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.		Fujifilm X-M1	3/5	+	..	77/100	4.5/5	4.5/5	Jun 2013	US$ 699	ebay.com
2.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	US$ 9 995	ebay.com
3.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	US$ 4 999	ebay.com
4.		Canon 1D X	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	US$ 6 799	ebay.com
5.		Fujifilm X-A1	..	..	..	..	4.5/5	4.5/5	Sep 2013	US$ 399	ebay.com
6.		Fujifilm X-A2	4/5	..	..	..	4.5/5	4.5/5	Jan 2015	US$ 399	ebay.com
7.		Fujifilm X-A10	..	..	..	..	4/5	4/5	Dec 2016	US$ 399	ebay.com
8.		Fujifilm X-E1	4/5	+ +	..	79/100	4.5/5	4.5/5	Sep 2012	US$ 999	ebay.com
9.		Fujifilm X-E2	4/5	..	..	80/100	4.5/5	5/5	Oct 2013	US$ 999	ebay.com
10.		Fujifilm X-E2S	4.5/5	..	..	77/100	4.5/5	4.5/5	Jan 2016	US$ 699	ebay.com
11.		Fujifilm X-Pro1	5/5	+ +	..	79/100	4.5/5	4.5/5	Jan 2012	US$ 1 699	ebay.com
12.		Fujifilm X-T10	4.5/5	+ +	..	80/100	5/5	5/5	May 2015	US$ 799	ebay.com
13.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	US$ 21 949	ebay.com
14.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	US$ 5 199	ebay.com
15.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	US$ 8 499	ebay.com
16.		Sony NEX-5R	..	..	..	..	4.5/5	4.5/5	Aug 2012	US$ 749	ebay.com
17.		Sony NEX-F3	4/5	..	..	74/100	4.5/5	4.5/5	May 2012	US$ 599	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. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, please note that some of the review sites have changed their methodology and reporting over time.

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Other camera comparisons

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