Olympus E-420 vs Pentax 645Z

The Olympus E-420 and the Pentax 645Z are two digital cameras that were revealed to the public, respectively, in March 2008 and April 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a Four Thirds (E-420) and a medium format (645Z) sensor. The Olympus has a resolution of 10 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 E-420		Pentax 645Z
Digital single lens reflex		Digital single lens reflex
Four Thirds lenses		Pentax 645 mount lenses
10 MP – Four Thirds sensor		51.1 MP – Medium Format sensor
no Video		1080/60i Video
ISO 100-1,600		ISO 100-204,800
Optical viewfinder		Optical viewfinder
2.7" LCD – 215k dots		3.2" LCD – 1037k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
3.5 shutter flaps per second		3 shutter flaps per second
not weather sealed		Weathersealed body
500 shots per battery charge		650 shots per battery charge
130 x 91 x 53 mm, 440 g		156 x 117 x 123 mm, 1550 g

Check E-420 offers at
ebay.com
Check 645Z offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus E-420 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

An illustration of the physical size and weight of the Olympus E-420 and the Pentax 645Z 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 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 645Z is considerably larger (54 percent) than the Olympus E-420. Moreover, the 645Z is substantially heavier (252 percent) than the E-420. It is noteworthy in this context that the 645Z is splash and dust-proof, while the E-420 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 E-420 gets 500 shots out of its Olympus BLS-1 battery, while the 645Z can take 650 images on a single charge of its Pentax D-LI90 power pack.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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	Street Price
1.		Olympus E-420	130 mm	91 mm	53 mm	440 g	500	n	Mar 2008	US$ 599	ebay.com
2.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	US$ 8 499	ebay.com
3.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	US$ 3 699	ebay.com
4.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	US$ 3 699	ebay.com
5.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	US$ 8 995	ebay.com
6.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	US$ 7 449	ebay.com
7.		Nikon D40X	124 mm	94 mm	64 mm	522 g	520	n	Mar 2007	US$ 729	ebay.com
8.		Nikon D60	126 mm	94 mm	64 mm	522 g	500	n	Jan 2008	US$ 629	ebay.com
9.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	US$ 599	ebay.com
10.		Olympus E-400	130 mm	91 mm	53 mm	435 g	500	n	Sep 2006	US$ 699	ebay.com
11.		Olympus E-410	130 mm	91 mm	53 mm	435 g	500	n	Mar 2007	US$ 699	ebay.com
12.		Olympus E-450	130 mm	91 mm	53 mm	440 g	500	n	Mar 2009	US$ 499	ebay.com
13.		Olympus E-520	136 mm	92 mm	68 mm	535 g	750	n	May 2008	US$ 699	ebay.com
14.		Olympus E-600	130 mm	94 mm	60 mm	535 g	500	n	Aug 2009	US$ 449	ebay.com
15.		Olympus E-620	130 mm	94 mm	60 mm	521 g	500	n	Feb 2009	US$ 699	ebay.com
16.		Panasonic L10	135 mm	96 mm	78 mm	556 g	450	n	Aug 2007	US$ 599	ebay.com
17.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	US$ 9 995	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The E-420 was launched at a markedly lower price (by 93 percent) than the 645Z, 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. 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 generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Olympus E-420 features a Four Thirds sensor and the Pentax 645Z a medium format sensor. The sensor area in the 645Z is 539 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 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 E-420 (10MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 4.74μm for the E-420) due to its larger sensor. Moreover, the 645Z is a much more recent model (by 6 years and 1 month) than the E-420, and its sensor will have benefitted from technological advances during this time that further 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 E-420 are 18.2 x 13.7 inches or 46.3 x 34.7 cm for good quality, 14.6 x 10.9 inches or 37.1 x 27.8 cm for very good quality, and 12.2 x 9.1 inches or 30.9 x 23.2 cm for excellent quality prints.

The Olympus E-420 has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Pentax 645Z are ISO 100 to ISO 204800 (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"). Of the two cameras under consideration, the 645Z offers substantially better image quality than the E-420 (overall score 45 points higher). The advantage is based on 4.5 bits higher color depth, 4.3 EV in additional dynamic range, and 3.1 stops in additional low light sensitivity. 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 E-420	Four Thirds	10.0	3648	2736	none	21.5	10.4	527	56
2.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
3.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
4.		Canon 5DS R	Full Frame	50.3	8688	5792	1080/30p	24.6	12.4	2308	86
5.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
6.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
7.		Nikon D40X	APS-C	10.0	3872	2592	none	22.4	11.4	516	63
8.		Nikon D60	APS-C	10.0	3872	2592	none	22.5	11.4	562	65
9.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
10.		Olympus E-400	Four Thirds	10.0	3648	2736	none	21.0	10.6	127	53
11.		Olympus E-410	Four Thirds	10.0	3648	2736	none	21.1	10.0	494	51
12.		Olympus E-450	Four Thirds	10.0	3648	2736	none	21.5	10.5	512	56
13.		Olympus E-520	Four Thirds	10.0	3648	2736	none	21.4	10.4	548	55
14.		Olympus E-600	Four Thirds	12.2	4032	3024	none	21.5	10.3	541	55
15.		Olympus E-620	Four Thirds	12.2	4032	3024	none	21.3	10.3	536	55
16.		Panasonic L10	Four Thirds	10.0	3648	2736	none	21.3	10.8	429	55
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 are not only capable of taking still images, but also of capturing video footage. The 645Z indeed provides for movie recording, while the E-420 does not. The highest resolution format that the 645Z can use is 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The E-420 and the 645Z are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinder in the 645Z offers a wider field of view (98%) than the one in the E-420 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the 645Z has a higher magnification (0.78x vs 0.46x), 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 Olympus E-420, the Pentax 645Z, 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 E-420	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
2.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
3.		Canon 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
4.		Canon 5DS R	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
5.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
6.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
7.		Nikon D40X	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
8.		Nikon D60	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
9.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
10.		Olympus E-400	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
11.		Olympus E-410	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
12.		Olympus E-450	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
13.		Olympus E-520	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	Y
14.		Olympus E-600	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
15.		Olympus E-620	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
16.		Panasonic L10	optical	n	2.5 / 207	swivel	n	1/4000s	3.0/s	Y	n
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 E-420 has one, while the 645Z does not. While the built-in flash of the E-420 is not very powerful, it can at times be useful as a fill-in light.

The Pentax 645Z 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.

The E-420 writes its imaging data to Compact Flash or xD Picture cards, while the 645Z uses SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.

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 E-420 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 E-420	Y	- / -	-	-	-	2.0	-	-	-
2.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
3.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
4.		Canon 5DS R	Y	mono / mono	Y	-	mini	3.0	-	-	-
5.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
6.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
7.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
8.		Nikon D60	Y	- / -	-	-	-	2.0	-	-	-
9.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
10.		Olympus E-400	Y	- / -	-	-	-	2.0	-	-	-
11.		Olympus E-410	Y	- / -	-	-	-	2.0	-	-	-
12.		Olympus E-450	Y	- / -	-	-	-	2.0	-	-	-
13.		Olympus E-520	Y	- / -	-	-	-	2.0	-	-	-
14.		Olympus E-600	Y	- / -	-	-	-	2.0	-	-	-
15.		Olympus E-620	Y	- / -	-	-	-	2.0	-	-	-
16.		Panasonic L10	Y	- / -	-	-	-	2.0	-	-	-
17.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-

Studio photographers will appreciate that the Pentax 645Z (unlike the E-420) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the E-420 and the 645Z have been discontinued, but can regularly be found used on ebay. Neither of the two has a direct successor, so they represent the end of the respective camera lines from Olympus and Pentax. Further information on the features and operation of the E-420 and 645Z can be found, respectively, in the Olympus E-420 Manual (free pdf) or the online Pentax 645Z Manual.

Review summary

So how do things add up? Is the Olympus E-420 better than the Pentax 645Z or vice versa? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Olympus E-420:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Faster burst: Shoots at higher frequency (3.5 vs 3 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (130x91mm vs 156x117mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 1110g or 72 percent) and hence easier to carry around.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (93 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in March 2008).

Arguments in favor of the Pentax 645Z:

• More detail: Has more megapixels (51.1 vs 10MP), which boosts linear resolution by 126%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores substantially higher (45 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (4.5 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (4.3 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (3.1 stops ISO advantage).
• Broader imaging potential: Can capture not only stills but also 1080/60i video.
• More complete view: Has a viewfinder with a larger field of view (98% vs 95%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.46x).
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.2" vs 2.7") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1037k vs 215k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Gets more shots (650 versus 500) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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.
• More modern: Reflects 6 years and 1 month of technical progress since the E-420 launch.

If the count of relative strengths (bullet points above) is taken as a measure, the 645Z is the clear winner of the contest (19 : 7 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 E-420 and the Pentax 645Z place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing whether the two cameras rank among the cream of the crop.

In any case, while the specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains incomplete and does no justice, for example, to the way the E-420 or the 645Z 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 hands-on reviews by experts 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.		Olympus E-420	..	85/100	..	+ +	4/5	4.5/5	Mar 2008	US$ 599	ebay.com
2.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	US$ 8 499	ebay.com
3.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	US$ 3 699	ebay.com
4.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	US$ 3 699	ebay.com
5.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	US$ 8 995	ebay.com
6.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	US$ 7 449	ebay.com
7.		Nikon D40X	..	79/100	..	+ +	4/5	4/5	Mar 2007	US$ 729	ebay.com
8.		Nikon D60	..	80/100	..	+ +	4/5	4.5/5	Jan 2008	US$ 629	ebay.com
9.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	US$ 599	ebay.com
10.		Olympus E-400	..	85/100	..	..	4/5	4/5	Sep 2006	US$ 699	ebay.com
11.		Olympus E-410	..	86/100	..	+ +	4/5	4.5/5	Mar 2007	US$ 699	ebay.com
12.		Olympus E-450	..	..	..	..	4/5	4/5	Mar 2009	US$ 499	ebay.com
13.		Olympus E-520	..	87/100	..	+ +	4.5/5	4.5/5	May 2008	US$ 699	ebay.com
14.		Olympus E-600	..	..	..	..	..	4.5/5	Aug 2009	US$ 449	ebay.com
15.		Olympus E-620	3/5	88/100	..	72/100	4.5/5	5/5	Feb 2009	US$ 699	ebay.com
16.		Panasonic L10	..	85/100	..	+	3.5/5	4/5	Aug 2007	US$ 599	ebay.com
17.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	US$ 9 995	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. A score, therefore, has to be seen in close connection to the price and market introduction time 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. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check E-420 offers at
ebay.com
Check 645Z offers at
ebay.com

Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

Check E-420 offers at
ebay.com
Check 645Z offers at
ebay.com

Did you notice an error on this page? If so, please get in touch, so that we can correct the information.