Epson R-D1 vs Sony A6400

The Epson R-D1 and the Sony Alpha A6400 are two enthusiast cameras that were announced, respectively, in March 2004 and January 2019. The R-D1 is a rangefinder-focusing mirrorless, while the A6400 is a mirrorless interchangeable lens camera. Both cameras are equipped with an APS-C sensor. The Epson has a resolution of 6 megapixels, whereas the Sony provides 24 MP.

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

Headline Specifications

Epson R-D1		Sony A6400
Rangefinder camera		Mirrorless system camera
Leica M mount lenses		Sony E mount lenses
6 MP – APS-C sensor		24 MP – APS-C sensor
no Video		4K/30p Video
ISO 200-1,600		ISO 100-32,000 (100 - 102,400)
Optical viewfinder		Electronic viewfinder (2359k dots)
2.0" LCD – 235k dots		3.0" LCD – 922k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
1 shutter flaps per second		11 shutter flaps per second
not weather sealed		Weathersealed body
142 x 89 x 40 mm, 620 g		120 x 67 x 50 mm, 403 g

Check R-D1 offers at
ebay.com
Check A6400 price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Epson R-D1 and the Sony Alpha A6400? 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 Epson R-D1 and the Sony A6400 are illustrated 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A6400 is considerably smaller (36 percent) than the Epson R-D1. Moreover, the A6400 is substantially lighter (35 percent) than the R-D1. It is noteworthy in this context that the A6400 is splash and dust-proof, while the R-D1 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. Both cameras have similarly sized sensors, but DSLRs have a larger flange-to-focal plane distance than mirrorless cameras, which imposes contraints on the optical engineering process and generally leads to bigger and heavier lenses. You can compare the optics available for the two cameras in the Leica M Lens Catalog (R-D1) and the Sony E-Mount Lens Catalog (A6400).

The power pack in the A6400 can be charged via the USB port, which can be very convenient when travelling.

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.		Epson R-D1	142 mm	89 mm	40 mm	620 g	..	n	Mar 2004	2,999	ebay.com
2.		Sony A6400	120 mm	67 mm	50 mm	403 g	410	Y	Jan 2019	899	amazon.com
3.		Canon Rebel	142 mm	99 mm	72 mm	649 g	400	n	Aug 2003	899	ebay.com
4.		Leica CL	131 mm	78 mm	45 mm	403 g	220	n	Nov 2017	2,795	ebay.com
5.		Leica M10	139 mm	80 mm	39 mm	660 g	210	Y	Jan 2017	6,595	ebay.com
6.		Leica X-U Typ 113	140 mm	79 mm	88 mm	635 g	450	Y	Jan 2016	2,950	ebay.com
7.		Leica X Vario	133 mm	73 mm	95 mm	680 g	450	n	Jun 2013	2,850	ebay.com
8.		Leica M9	139 mm	80 mm	37 mm	585 g	..	n	Sep 2009	7,999	ebay.com
9.		Nikon D5300	125 mm	98 mm	76 mm	480 g	600	n	Oct 2013	799	ebay.com
10.		Nikon D40	124 mm	94 mm	64 mm	522 g	470	n	Nov 2006	499	ebay.com
11.		Nikon D50	133 mm	102 mm	76 mm	620 g	400	n	Apr 2005	749	ebay.com
12.		Nikon D70s	140 mm	111 mm	78 mm	679 g	500	n	Apr 2005	899	ebay.com
13.		Nikon D70	140 mm	111 mm	78 mm	679 g	400	n	Jan 2004	999	ebay.com
14.		Sony A6100	120 mm	67 mm	59 mm	396 g	420	n	Aug 2019	749	ebay.com
15.		Sony A6300	120 mm	67 mm	49 mm	404 g	400	Y	Feb 2016	999	ebay.com
16.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
17.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The A6400 was launched at a markedly lower price (by 70 percent) than the R-D1, 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 sensor inside a digital camera is one of the key determinants 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.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the A6400 is 1 percent smaller. They nevertheless have the same format factor of 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a slightly smaller sensor, the A6400 offers a higher resolution of 24 megapixels, compared with 6 MP of the R-D1. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.91μm versus 7.85μm for the R-D1). However, it should be noted that the A6400 is much more recent (by 14 years and 10 months) than the R-D1, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently.

The resolution advantage of the Sony A6400 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A6400 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 Epson R-D1 are 15 x 10 inches or 38.2 x 25.4 cm for good quality, 12 x 8 inches or 30.6 x 20.3 cm for very good quality, and 10 x 6.7 inches or 25.5 x 16.9 cm for excellent quality prints.

The A6400 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Epson R-D1 has a native sensitivity range from ISO 200 to ISO 1600. The corresponding ISO settings for the Sony Alpha A6400 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 100-102400.

In terms of underlying technology, the R-D1 is build around a CCD sensor, while the A6400 uses a 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). 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.		Epson R-D1	APS-C	6.0	3008	2000	none	21.1	10.4	564	55
2.		Sony A6400	APS-C	24.0	6000	4000	4K/30p	24.0	13.6	1431	83
3.		Canon Rebel	APS-C	6.3	3072	2048	none	21.0	10.8	544	55
4.		Leica CL	APS-C	24.1	6014	4014	4K/30p	24.0	13.3	1788	82
5.		Leica M10	Full Frame	23.8	5952	3992	none	24.4	13.2	2133	86
6.		Leica X-U Typ 113	APS-C	16.1	4928	3264	1080/30p	23.8	13.0	1614	80
7.		Leica X Vario	APS-C	16.1	4928	3272	1080/30p	23.4	12.7	1320	78
8.		Leica M9	Full Frame	18.1	5212	3472	none	22.5	11.7	884	69
9.		Nikon D5300	APS-C	24.0	6000	4000	1080/60p	24.0	13.9	1338	83
10.		Nikon D40	APS-C	6.0	3008	2000	none	21.0	11.0	561	56
11.		Nikon D50	APS-C	6.0	3008	2000	none	20.9	10.8	560	55
12.		Nikon D70s	APS-C	6.0	3008	2000	none	20.4	10.3	529	50
13.		Nikon D70	APS-C	6.0	3008	2000	none	20.4	10.3	529	50
14.		Sony A6100	APS-C	24.0	6000	4000	4K/30p	24.1	13.6	1947	84
15.		Sony A6300	APS-C	24.0	6000	4000	4K/30p	24.4	13.7	1437	85
16.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
17.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
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 A6400 indeed provides for movie recording, while the R-D1 does not. The highest resolution format that the A6400 can use is 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A6400 has an electronic viewfinder (2359k dots), while the R-D1 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 table below summarizes some of the other core capabilities of the Epson R-D1 and Sony A6400 in connection with corresponding information for a sample of similar 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.		Epson R-D1	optical	n	2.0 / 235	fixed	n	1/2000s	1.0/s	n	n
2.		Sony A6400	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	n
3.		Canon Rebel	optical	n	1.8 / 118	fixed	n	1/4000s	2.5/s	Y	n
4.		Leica CL	2360	Y	3.0 / 1040	fixed	Y	1/8000s	10.0/s	n	n
5.		Leica M10	optical	n	3.0 / 1037	fixed	n	1/4000s	5.0/s	n	n
6.		Leica X-U Typ 113	optional	n	3.0 / 920	fixed	n	1/2000s	5.0/s	Y	n
7.		Leica X Vario	optional	n	3.0 / 920	fixed	n	1/2000s	5.0/s	Y	n
8.		Leica M9	optical	n	2.5 / 230	fixed	n	1/4000s	2.0/s	n	n
9.		Nikon D5300	optical	n	3.2 / 1037	swivel	n	1/4000s	5.0/s	Y	n
10.		Nikon D40	optical	n	2.5 / 230	fixed	n	1/4000s	2.5/s	Y	n
11.		Nikon D50	optical	n	2.0 / 130	fixed	n	1/4000s	2.5/s	Y	n
12.		Nikon D70s	optical	n	2.0 / 130	fixed	n	1/8000s	3.0/s	Y	n
13.		Nikon D70	optical	n	1.8 / 130	fixed	n	1/8000s	3.0/s	Y	n
14.		Sony A6100	1440	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	n
15.		Sony A6300	2359	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
16.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
17.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
Notes: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A6400 has a touchscreen, while the R-D1 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

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 A6400 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 R-D1 writes its imaging data to SDHC cards, while the A6400 uses SDXC or Memory Stick PRO Duo cards. The A6400 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the R-D1 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 Epson R-D1 and Sony Alpha A6400 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.		Epson R-D1	Y	- / -	-	-	-	-	-	-	-
2.		Sony A6400	Y	stereo / mono	Y	-	micro	2.0	Y	Y	Y
3.		Canon Rebel	Y	- / -	-	-	-	1.1	-	-	-
4.		Leica CL	Y	stereo / mono	-	-	-	-	Y	-	-
5.		Leica M10	Y	- / -	-	-	-	-	Y	-	-
6.		Leica X-U Typ 113	Y	stereo / mono	-	-	-	2.0	-	-	-
7.		Leica X Vario	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Leica M9	Y	- / -	-	-	-	2.0	-	-	-
9.		Nikon D5300	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
10.		Nikon D40	Y	- / -	-	-	-	2.0	-	-	-
11.		Nikon D50	Y	- / -	-	-	-	2.0	-	-	-
12.		Nikon D70s	Y	- / -	-	-	-	2.0	-	-	-
13.		Nikon D70	Y	- / -	-	-	-	1.0	-	-	-
14.		Sony A6100	Y	stereo / mono	Y	-	micro	2.0	Y	Y	Y
15.		Sony A6300	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
16.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
17.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the A6400 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the R-D1 does not provide wifi capability.

Studio photographers will appreciate that the Epson R-D1 (unlike the A6400) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

The A6400 is a recent model that features in the current product line-up of Sony. In contrast, the R-D1 has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the R-D1 from Epson. Further information on the features and operation of the R-D1 and A6400 can be found, respectively, in the Epson R-D1 Manual (free pdf) or the online Sony A6400 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Epson R-D1 or the Sony A6400 – 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 Epson R-D1:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• More heavily discounted: Has been available for much longer (launched in March 2004).

Advantages of the Sony Alpha A6400:

• More detail: Has more megapixels (24 vs 6MP), which boosts linear resolution by 100%.
• Broader imaging potential: Can capture not only stills but also 4K/30p video.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More framing info: Has an electronic viewfinder that displays shooting data.
• Larger screen: Has a bigger rear LCD (3.0" vs 2.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (922k vs 235k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
• Faster burst: Shoots at higher frequency (11 vs 1 flaps/sec) to capture the decisive moment.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• More compact: Is smaller (120x67mm vs 142x89mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 217g or 35 percent) and is thus easier to take along.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More affordable: Was introduced into a lower priced category (70 percent cheaper at launch).
• More modern: Reflects 14 years and 10 months of technical progress since the R-D1 launch.

If the count of relative strengths (bullet points above) is taken as a measure, the A6400 is the clear winner of the contest (23 : 3 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.

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 R-D1 or the A6400. 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 adjacent summary-table relays the overall verdicts of several of the most popular 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.		Epson R-D1	..	..	..	..	..	..	Mar 2004	2,999	ebay.com
2.		Sony A6400	4/5	+	4/5	85/100	4.5/5	4/5	Jan 2019	899	amazon.com
3.		Canon Rebel	..	..	..	+ +	..	..	Aug 2003	899	ebay.com
4.		Leica CL	..	..	4.2/5	..	..	4/5	Nov 2017	2,795	ebay.com
5.		Leica M10	4.5/5	..	..	..	4/5	4.5/5	Jan 2017	6,595	ebay.com
6.		Leica X-U Typ 113	3.5/5	..	..	..	..	3.5/5	Jan 2016	2,950	ebay.com
7.		Leica X Vario	3/5	..	..	..	4/5	4/5	Jun 2013	2,850	ebay.com
8.		Leica M9	..	..	..	..	4.5/5	..	Sep 2009	7,999	ebay.com
9.		Nikon D5300	4/5	+ +	..	79/100	4.5/5	4.5/5	Oct 2013	799	ebay.com
10.		Nikon D40	..	81/100	..	+ +	o	4.5/5	Nov 2006	499	ebay.com
11.		Nikon D50	..	78/100	..	+ +	4/5	4.5/5	Apr 2005	749	ebay.com
12.		Nikon D70s	..	..	..	..	..	5/5	Apr 2005	899	ebay.com
13.		Nikon D70	..	..	..	+ +	..	..	Jan 2004	999	ebay.com
14.		Sony A6100	..	..	4/5	82/100	4/5	5/5	Aug 2019	749	ebay.com
15.		Sony A6300	4.5/5	+	..	85/100	5/5	5/5	Feb 2016	999	ebay.com
16.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
17.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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Check A6400 price at
amazon.com

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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