Panasonic GX1 vs Sigma fp

The Panasonic Lumix DMC-GX1 and the Sigma fp are two digital cameras that were officially introduced, respectively, in November 2011 and July 2019. Both the GX1 and the fp are mirrorless interchangeable lens cameras that are based on a Four Thirds (GX1) and a full frame (fp) sensor. The Panasonic has a resolution of 15.8 megapixels, whereas the Sigma provides 24 MP.

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

Headline Specifications

Panasonic GX1		Sigma fp
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Leica L mount lenses
15.8 MP – Four Thirds sensor		24 MP – Full Frame sensor
1080/60p Video		4K/30p Video
ISO 160-12,800		ISO 100-25,600 (6 - 102,400)
Viewfinder optional		Viewfinder optional
3.0" LCD – 460k dots		3.2" LCD – 2100k dots
Fixed touchscreen		Fixed touchscreen
4.2 shutter flaps per second		12 shutter flaps per second
not weather sealed		Weathersealed body
320 shots per battery charge		280 shots per battery charge
116 x 68 x 39 mm, 318 g		113 x 70 x 45 mm, 422 g

Check GX1 offers at
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Check fp price at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DMC-GX1 and the Sigma fp? 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 Panasonic GX1 and the Sigma fp. 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Panasonic GX1 and the Sigma fp are of equal size. However, the fp is markedly heavier (33 percent) than the GX1. It is noteworthy in this context that the fp is splash and dust-proof, while the GX1 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 GX1 gets 320 shots out of its Panasonic DMW-BLD10 battery, while the fp can take 280 images on a single charge of its Sigma BP-51 power pack. The power pack in the fp can be charged via the USB port, which can be very convenient when travelling.

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.		Panasonic GX1	116 mm	68 mm	39 mm	318 g	320	n	Nov 2011	US$ 699	ebay.com
2.		Sigma fp	113 mm	70 mm	45 mm	422 g	280	Y	Jul 2019	US$ 1 899	amazon.com
3.		Fujifilm X-Pro3	141 mm	83 mm	46 mm	497 g	440	Y	Oct 2019	US$ 1 799	amazon.com
4.		Nikon D780	144 mm	116 mm	76 mm	840 g	2260	Y	Jan 2020	US$ 2 299	amazon.com
5.		Panasonic G2	124 mm	84 mm	74 mm	428 g	360	n	Mar 2010	US$ 599	ebay.com
6.		Panasonic G3	115 mm	84 mm	47 mm	336 g	270	n	May 2011	US$ 599	ebay.com
7.		Panasonic G5	120 mm	83 mm	71 mm	396 g	320	n	Jul 2012	US$ 599	ebay.com
8.		Panasonic G6	122 mm	85 mm	71 mm	390 g	340	n	Apr 2013	US$ 599	ebay.com
9.		Panasonic GF1	119 mm	71 mm	36 mm	385 g	380	n	Sep 2009	US$ 749	ebay.com
10.		Panasonic GF2	113 mm	68 mm	33 mm	310 g	300	n	Nov 2010	US$ 549	ebay.com
11.		Panasonic GF3	108 mm	67 mm	32 mm	264 g	300	n	Jun 2011	US$ 549	ebay.com
12.		Panasonic GF5	108 mm	67 mm	37 mm	267 g	360	n	Apr 2012	US$ 499	ebay.com
13.		Panasonic GH2	124 mm	90 mm	76 mm	442 g	330	n	Sep 2010	US$ 899	ebay.com
14.		Panasonic GM1	99 mm	55 mm	30 mm	204 g	230	n	Oct 2013	US$ 749	ebay.com
15.		Panasonic S1	149 mm	110 mm	97 mm	1017 g	400	Y	Feb 2019	US$ 2 499	ebay.com
16.		Panasonic S1H	151 mm	114 mm	110 mm	1052 g	400	Y	May 2019	US$ 3 999	amazon.com
17.		Panasonic S5	133 mm	98 mm	82 mm	714 g	440	Y	Sep 2020	US$ 1 999	amazon.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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Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The GX1 was launched at a markedly lower price (by 63 percent) than the fp, 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 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. 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 Panasonic GX1 features a Four Thirds sensor and the Sigma fp a full frame sensor. The sensor area in the fp is 281 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.0. The sensor in the GX1 has a native 4:3 aspect ratio, while the one in the fp offers a 3:2 aspect.

With 24MP, the fp offers a higher resolution than the GX1 (15.8MP), but the fp nevertheless has larger individual pixels (pixel pitch of 5.98μm versus 3.77μm for the GX1) due to its larger sensor. Moreover, the fp is a much more recent model (by 7 years and 8 months) than the GX1, 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 fp has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sigma fp implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the fp for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Panasonic GX1 are 23 x 17.2 inches or 58.3 x 43.8 cm for good quality, 18.4 x 13.8 inches or 46.7 x 35 cm for very good quality, and 15.3 x 11.5 inches or 38.9 x 29.2 cm for excellent quality prints.

The Panasonic Lumix DMC-GX1 has a native sensitivity range from ISO 160 to ISO 12800. The corresponding ISO settings for the Sigma fp are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 6-102400.

In terms of underlying technology, the GX1 is build around a CMOS sensor, while the fp uses a BSI-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 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"). 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 GX1	Four Thirds	15.8	4592	3448	1080/60p	20.8	10.6	703	55
2.		Sigma fp	Full Frame	24.0	6000	4000	4K/30p	25.2	14.2	2829	94
3.		Fujifilm X-Pro3	APS-C	26.0	6240	4160	4K/30p	24.1	13.6	1968	84
4.		Nikon D780	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	2877	95
5.		Panasonic G2	Four Thirds	12.0	4000	3000	720/30p	21.2	10.3	493	53
6.		Panasonic G3	Four Thirds	15.8	4592	3448	1080/60i	21.0	10.6	667	56
7.		Panasonic G5	Four Thirds	15.9	4608	3456	1080/60p	21.4	11.6	618	61
8.		Panasonic G6	Four Thirds	15.9	4608	3456	1080/60p	21.3	11.5	639	61
9.		Panasonic GF1	Four Thirds	12.0	4000	3000	720/30p	21.2	10.3	513	54
10.		Panasonic GF2	Four Thirds	12.0	4000	3000	1080/60i	21.2	10.3	506	54
11.		Panasonic GF3	Four Thirds	12.0	4000	3000	1080/60i	20.6	10.1	459	50
12.		Panasonic GF5	Four Thirds	12.0	4000	3000	1080/60i	20.5	10.0	573	50
13.		Panasonic GH2	Four Thirds	15.9	4608	3456	1080/60i	21.2	11.3	655	60
14.		Panasonic GM1	Four Thirds	15.8	4592	3448	1080/60i	22.3	11.7	660	66
15.		Panasonic S1	Full Frame	24.0	6000	4000	4K/60p	25.2	14.5	3333	95
16.		Panasonic S1H	Full Frame	24.0	6000	4000	6K/30p	25.2	14.2	2805	94
17.		Panasonic S5	Full Frame	24.0	6000	4000	4K/60p	25.1	14.5	2697	94
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. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the fp provides a better video resolution than the GX1. It can shoot movie footage at 4K/30p, while the Panasonic is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The GX1 and the fp are similar in the sense that neither of the two has a viewfinder. The images are, thus, framed using live view on the rear LCD. However, optional viewfinders – the DMW-LVF2 for the GX1 and the EVF-11 for the fp – are available as accessories. The following table reports on some other key feature differences and similarities of the Panasonic GX1, the Sigma fp, 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.		Panasonic GX1	optional	n	3.0 / 460	fixed	Y	1/4000s	4.2/s	Y	n
2.		Sigma fp	optional	n	3.2 / 2100	fixed	Y	1/8000s	12.0/s	n	n
3.		Fujifilm X-Pro3	3690	n	3.0 / 1620	tilting	Y	1/8000s	8.0/s	n	n
4.		Nikon D780	optical	Y	3.2 / 2359	tilting	Y	1/8000s	12.0/s	n	n
5.		Panasonic G2	1440	n	3.0 / 460	swivel	Y	1/4000s	2.6/s	Y	n
6.		Panasonic G3	1440	n	3.0 / 460	swivel	Y	1/4000s	4.0/s	Y	n
7.		Panasonic G5	1440	n	3.0 / 920	swivel	Y	1/4000s	6.0/s	Y	n
8.		Panasonic G6	1440	n	3.0 / 1036	swivel	Y	1/4000s	7.0/s	Y	n
9.		Panasonic GF1	optional	n	3.0 / 460	fixed	n	1/4000s	3.0/s	Y	n
10.		Panasonic GF2	optional	n	3.0 / 460	fixed	Y	1/4000s	2.6/s	Y	n
11.		Panasonic GF3	none	n	3.0 / 460	fixed	Y	1/4000s	3.2/s	Y	n
12.		Panasonic GF5	none	n	3.0 / 920	fixed	Y	1/4000s	4.0/s	Y	n
13.		Panasonic GH2	1534	n	3.0 / 460	swivel	n	1/4000s	3.0/s	Y	n
14.		Panasonic GM1	none	n	3.0 / 1036	fixed	Y	1/500s	5.0/s	Y	n
15.		Panasonic S1	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
16.		Panasonic S1H	5760	Y	3.2 / 2330	swivel	Y	1/8000s	9.0/s	n	Y
17.		Panasonic S5	2360	n	3.0 / 1840	swivel	Y	1/8000s	7.0/s	n	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 GX1 has one, while the fp does not. While the built-in flash of the GX1 is not very powerful, it can at times be useful as a fill-in light.

The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, the fp is one of those camera that have an additional electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).

The Sigma fp 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 GX1 and the fp write their files to SDXC cards. The fp supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the GX1 can use UHS-I cards (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 Panasonic Lumix DMC-GX1 and Sigma fp 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 GX1	Y	stereo / mono	-	-	mini	2.0	-	-	-
2.		Sigma fp	Y	stereo / mono	Y	-	micro	3.1	-	-	-
3.		Fujifilm X-Pro3	Y	stereo / mono	Y	-	-	3.1	Y	-	Y
4.		Nikon D780	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
5.		Panasonic G2	Y	stereo / mono	-	-	mini	2.0	-	-	-
6.		Panasonic G3	Y	stereo / mono	-	-	mini	2.0	-	-	-
7.		Panasonic G5	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Panasonic G6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
9.		Panasonic GF1	Y	mono / mono	-	-	mini	2.0	-	-	-
10.		Panasonic GF2	Y	stereo / mono	-	-	mini	2.0	-	-	-
11.		Panasonic GF3	-	stereo / mono	-	-	mini	2.0	-	-	-
12.		Panasonic GF5	-	stereo / mono	-	-	mini	2.0	-	-	-
13.		Panasonic GH2	Y	stereo / mono	Y	-	mini	2.0	-	-	-
14.		Panasonic GM1	-	stereo / mono	-	-	micro	2.0	Y	-	-
15.		Panasonic S1	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
16.		Panasonic S1H	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
17.		Panasonic S5	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y

It is notable that the fp has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The GX1 does not feature such a mic input.

The fp is a recent model that features in the current product line-up of Sigma. In contrast, the GX1 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the GX1 was succeeded by the Panasonic GX7. Further information on the features and operation of the GX1 and fp can be found, respectively, in the Panasonic GX1 Manual (free pdf) or the online Sigma fp Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Panasonic GX1 or the Sigma fp – 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.

Reasons to prefer the Panasonic Lumix DMC-GX1:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Less heavy: Is lighter (by 104g or 25 percent) and hence easier to carry around.
• Longer lasting: Can take more shots (320 versus 280) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (63 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in November 2011).

Arguments in favor of the Sigma fp:

• More detail: Has more megapixels (24 vs 15.8MP), which boosts linear resolution by 26%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Is equipped with a larger and more technologically advanced sensor.
• Richer colors: The sensor size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• 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 (2100k vs 460k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 4.2 flaps/sec) to capture the decisive moment.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More modern: Reflects 7 years and 8 months of technical progress since the GX1 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the fp is the clear winner of the contest (19 : 6 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 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 GX1 and the Sigma fp place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the GX1 or the fp. 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.		Panasonic GX1	3/5	+	..	77/100	4.5/5	4.5/5	Nov 2011	US$ 699	ebay.com
2.		Sigma fp	4/5	..	4/5	..	4/5	4.5/5	Jul 2019	US$ 1 899	amazon.com
3.		Fujifilm X-Pro3	4/5	+	4/5	85/100	4/5	..	Oct 2019	US$ 1 799	amazon.com
4.		Nikon D780	5/5	..	5/5	87/100	4.5/5	4.5/5	Jan 2020	US$ 2 299	amazon.com
5.		Panasonic G2	..	..	..	72/100	4/5	4.5/5	Mar 2010	US$ 599	ebay.com
6.		Panasonic G3	3/5	+ +	..	75/100	4.5/5	5/5	May 2011	US$ 599	ebay.com
7.		Panasonic G5	3/5	+ +	..	..	4.5/5	4.5/5	Jul 2012	US$ 599	ebay.com
8.		Panasonic G6	4/5	+ +	..	..	5/5	4.5/5	Apr 2013	US$ 599	ebay.com
9.		Panasonic GF1	..	85/100	..	69/100	4.5/5	4.5/5	Sep 2009	US$ 749	ebay.com
10.		Panasonic GF2	3/5	82/100	..	70/100	4.5/5	4.5/5	Nov 2010	US$ 549	ebay.com
11.		Panasonic GF3	3/5	82/100	..	71/100	4.5/5	4/5	Jun 2011	US$ 549	ebay.com
12.		Panasonic GF5	3/5	..	..	..	4.5/5	4.5/5	Apr 2012	US$ 499	ebay.com
13.		Panasonic GH2	5/5	+ +	..	79/100	4.5/5	5/5	Sep 2010	US$ 899	ebay.com
14.		Panasonic GM1	3/5	+	..	78/100	5/5	4.5/5	Oct 2013	US$ 749	ebay.com
15.		Panasonic S1	4.5/5	+ +	4.5/5	88/100	4.5/5	4/5	Feb 2019	US$ 2 499	ebay.com
16.		Panasonic S1H	..	..	4/5	90/100	..	..	May 2019	US$ 3 999	amazon.com
17.		Panasonic S5	4.5/5	+ +	4.5/5	88/100	4.5/5	4.5/5	Sep 2020	US$ 1 999	amazon.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. 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 your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

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