Panasonic G1 vs Pentax 645Z

The Panasonic Lumix DMC-G1 and the Pentax 645Z are two digital cameras that were revealed to the public, respectively, in September 2008 and April 2014. The G1 is a mirrorless interchangeable lens camera, while the 645Z is a DSLR. The cameras are based on a Four Thirds (G1) and a medium format (645Z) sensor. The Panasonic 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

Panasonic G1		Pentax 645Z
Mirrorless system camera		Digital single lens reflex
Micro Four Thirds lenses		Pentax 645 mount lenses
12 MP – Four Thirds sensor		51.1 MP – Medium Format sensor
no Video		1080/60i Video
ISO 100-1,600 (100 - 3,200)		ISO 100-204,800
Electronic viewfinder (1440k dots)		Optical viewfinder
3.0" LCD – 460k dots		3.2" LCD – 1037k dots
Swivel screen (not touch-sensitive)		Tilting screen (no touchscreen)
3 shutter flaps per second		3 shutter flaps per second
not weather sealed		Weathersealed body
410 shots per battery charge		650 shots per battery charge
124 x 84 x 45 mm, 360 g		156 x 117 x 123 mm, 1550 g

Check G1 offers at
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Check 645Z offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DMC-G1 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 Panasonic G1 and the Pentax 645Z are illustrated in the side-by-side display below. 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 645Z is considerably larger (75 percent) than the Panasonic G1. Moreover, the 645Z is substantially heavier (331 percent) than the G1. It is noteworthy in this context that the 645Z is splash and dust-proof, while the G1 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 G1 gets 410 shots out of its Panasonic DMW-BLB13 battery, while the 645Z can take 650 images on a single charge of its Pentax D-LI90 power pack.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.		Panasonic G1	124 mm	84 mm	45 mm	360 g	410	n	Sep 2008	599	ebay.com
2.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
3.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
4.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
5.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	8,995	ebay.com
6.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
7.		Olympus E-410	130 mm	91 mm	53 mm	435 g	500	n	Mar 2007	699	ebay.com
8.		Panasonic GF6	111 mm	65 mm	38 mm	323 g	340	n	Apr 2013	499	ebay.com
9.		Panasonic GF5	108 mm	67 mm	37 mm	267 g	360	n	Apr 2012	499	ebay.com
10.		Panasonic GF3	108 mm	67 mm	32 mm	264 g	300	n	Jun 2011	549	ebay.com
11.		Panasonic G10	124 mm	84 mm	74 mm	388 g	380	n	Mar 2010	499	ebay.com
12.		Panasonic G2	124 mm	84 mm	74 mm	428 g	360	n	Mar 2010	599	ebay.com
13.		Panasonic GF2	113 mm	68 mm	33 mm	310 g	300	n	Nov 2010	549	ebay.com
14.		Panasonic GF1	119 mm	71 mm	36 mm	385 g	380	n	Sep 2009	749	ebay.com
15.		Panasonic GH1	124 mm	90 mm	45 mm	385 g	300	n	Mar 2009	899	ebay.com
16.		Panasonic L10	135 mm	96 mm	78 mm	556 g	450	n	Aug 2007	599	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.
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 G1 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 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. 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 Panasonic G1 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 G1 (12MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 4.33μm for the G1) due to its larger sensor. Moreover, the 645Z is a much more recent model (by 5 years and 7 months) than the G1, 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 Panasonic G1 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 Panasonic Lumix DMC-G1 has a native sensitivity range from ISO 100 to ISO 1600, which can be extended to ISO 100-3200. 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 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. Of the two cameras under consideration, the 645Z offers substantially better image quality than the G1 (overall score 48 points higher). The advantage is based on 4.9 bits higher color depth, 4.4 EV in additional dynamic range, and 3.3 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.		Panasonic G1	Four Thirds	12.0	4000	3000	none	21.1	10.3	463	53
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.		Olympus E-410	Four Thirds	10.0	3648	2736	none	21.1	10.0	494	51
8.		Panasonic GF6	Four Thirds	15.8	4592	3448	1080/60i	20.7	10.6	622	54
9.		Panasonic GF5	Four Thirds	12.0	4000	3000	1080/60i	20.5	10.0	573	50
10.		Panasonic GF3	Four Thirds	12.0	4000	3000	1080/60i	20.6	10.1	459	50
11.		Panasonic G10	Four Thirds	12.0	4000	3000	720/30p	21.2	10.1	411	52
12.		Panasonic G2	Four Thirds	12.0	4000	3000	720/30p	21.2	10.3	493	53
13.		Panasonic GF2	Four Thirds	12.0	4000	3000	1080/60i	21.2	10.3	506	54
14.		Panasonic GF1	Four Thirds	12.0	4000	3000	720/30p	21.2	10.3	513	54
15.		Panasonic GH1	Four Thirds	12.0	4000	3000	1080/24p	21.6	11.6	772	64
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

Many modern cameras cannot only take still pictures, but also record videos. The 645Z indeed provides for movie recording, while the G1 does not. The highest resolution format that the 645Z can use is 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the G1 has an electronic viewfinder (1440k dots), while the 645Z has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinder in the G1 offers a wider field of view (100%) than the one in the 645Z (98%), so that a larger proportion of the captured image is visible in the finder. On the other hand, the viewfinder of the 645Z has a higher magnification (0.78x vs 0.70x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Panasonic G1 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.		Panasonic G1	1440	n	3.0 / 460	swivel	n	1/4000s	3.0/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.		Olympus E-410	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
8.		Panasonic GF6	none	n	3.0 / 1040	tilting	Y	1/4000s	4.2/s	Y	n
9.		Panasonic GF5	none	n	3.0 / 920	fixed	Y	1/4000s	4.0/s	Y	n
10.		Panasonic GF3	none	n	3.0 / 460	fixed	Y	1/4000s	3.2/s	Y	n
11.		Panasonic G10	202	n	3.0 / 460	fixed	n	1/4000s	2.6/s	Y	n
12.		Panasonic G2	1440	n	3.0 / 460	swivel	Y	1/4000s	2.6/s	Y	n
13.		Panasonic GF2	optional	n	3.0 / 460	fixed	Y	1/4000s	2.6/s	Y	n
14.		Panasonic GF1	optional	n	3.0 / 460	fixed	n	1/4000s	3.0/s	Y	n
15.		Panasonic GH1	1440	n	3.0 / 460	swivel	n	1/4000s	3.0/s	Y	n
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 G1 has one, while the 645Z does not. While the built-in flash of the G1 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 G1 writes its imaging data to SDHC cards, while the 645Z uses SDXC cards. The 645Z features dual card slots, which can be very useful in case a memory card fails. In contrast, the G1 only has one slot. The 645Z supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the G1 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 Panasonic Lumix DMC-G1 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.		Panasonic G1	Y	- / -	-	-	mini	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.		Olympus E-410	Y	- / -	-	-	-	2.0	-	-	-
8.		Panasonic GF6	-	stereo / mono	-	-	mini	2.0	Y	Y	-
9.		Panasonic GF5	-	stereo / mono	-	-	mini	2.0	-	-	-
10.		Panasonic GF3	-	stereo / mono	-	-	mini	2.0	-	-	-
11.		Panasonic G10	Y	mono / -	-	-	mini	2.0	-	-	-
12.		Panasonic G2	Y	stereo / mono	-	-	mini	2.0	-	-	-
13.		Panasonic GF2	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Panasonic GF1	Y	mono / mono	-	-	mini	2.0	-	-	-
15.		Panasonic GH1	Y	stereo / -	Y	-	mini	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 G1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the G1 and the 645Z have been discontinued, but can regularly be found used on ebay. The G1 was replaced by the Panasonic G2, while the 645Z does not have a direct successor. Further information on the features and operation of the G1 and 645Z can be found, respectively, in the Panasonic G1 Manual (free pdf) or the online Pentax 645Z Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Panasonic G1 and the Pentax 645Z? Which camera is better? The listing below highlights the relative strengths of the two models.

Advantages of the Panasonic Lumix DMC-G1:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• More framing info: Has an electronic viewfinder that displays shooting data.
• More complete view: Has a viewfinder with a larger field of view (100% vs 98%).
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• More compact: Is smaller (124x84mm vs 156x117mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 1190g or 77 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.
• 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 September 2008).

Arguments in favor 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: Scores substantially higher (48 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (4.9 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (4.4 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (3.3 stops ISO advantage).
• Broader imaging potential: Can capture not only stills but also 1080/60i video.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.70x).
• 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).
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Gets more shots (650 versus 410) 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.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Reflects 5 years and 7 months of technical progress since the G1 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the 645Z is the clear winner of the contest (20 : 11 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Panasonic G1 and the Pentax 645Z 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the G1 or the 645Z. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

Expert reviews

This is where reviews by experts come in. 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 (USD)	Street Price
1.		Panasonic G1	..	+ +	..	70/100	4/5	4.5/5	Sep 2008	599	ebay.com
2.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
3.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	3,699	ebay.com
4.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	3,699	ebay.com
5.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	8,995	ebay.com
6.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
7.		Olympus E-410	..	86/100	..	+ +	4/5	4.5/5	Mar 2007	699	ebay.com
8.		Panasonic GF6	..	+ +	..	..	4.5/5	4.5/5	Apr 2013	499	ebay.com
9.		Panasonic GF5	3/5	..	..	..	4.5/5	4.5/5	Apr 2012	499	ebay.com
10.		Panasonic GF3	3/5	82/100	..	71/100	4.5/5	4/5	Jun 2011	549	ebay.com
11.		Panasonic G10	3/5	..	..	70/100	4/5	4/5	Mar 2010	499	ebay.com
12.		Panasonic G2	..	..	..	72/100	4/5	4.5/5	Mar 2010	599	ebay.com
13.		Panasonic GF2	3/5	82/100	..	70/100	4.5/5	4.5/5	Nov 2010	549	ebay.com
14.		Panasonic GF1	..	85/100	..	69/100	4.5/5	4.5/5	Sep 2009	749	ebay.com
15.		Panasonic GH1	..	+ +	..	72/100	4.5/5	4.5/5	Mar 2009	899	ebay.com
16.		Panasonic L10	..	85/100	..	+	3.5/5	4/5	Aug 2007	599	ebay.com
17.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	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 were established in reference to similarly priced cameras that were available in the market at the time of the review. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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.

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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 your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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