Epson R-D1 vs Sony A7R IV

The Epson R-D1 and the Sony Alpha A7R IV are two enthusiast cameras that were revealed to the public, respectively, in March 2004 and July 2019. The R-D1 is a rangefinder-focusing mirrorless, while the A7R IV is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (R-D1) and a full frame (A7R IV) sensor. The Epson has a resolution of 6 megapixels, whereas the Sony provides 60.2 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 A7R IV
Rangefinder camera		Mirrorless system camera
Leica M mount lenses		Sony E mount lenses
6 MP – APS-C sensor		60.2 MP – Full Frame sensor
no Video		4K/30p Video
ISO 200-1,600		ISO 100-32,000 (50 - 102,400)
Optical viewfinder		Electronic viewfinder (5760k dots)
2.0" LCD – 235k dots		3.0" LCD – 1440k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
1 shutter flaps per second		10 shutter flaps per second
no shake reduction		In-body stabilization
not weather sealed		Weathersealed body
142 x 89 x 40 mm, 620 g		129 x 96 x 78 mm, 665 g

Check R-D1 offers at
ebay.com
Check A7R IV offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Epson R-D1 and the Sony Alpha A7R IV? 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 A7R IV 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 Sony A7R IV is somewhat smaller (2 percent) than the Epson R-D1. However, the A7R IV is markedly heavier (7 percent) than the R-D1. It is noteworthy in this context that the A7R IV 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. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Leica M Lens Catalog (R-D1) and the Sony FE Lens Catalog (A7R IV).

The power pack in the A7R IV can be charged via the USB port, which can be very convenient when travelling.

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 (USD)	Street Price
1.		Epson R-D1	142 mm	89 mm	40 mm	620 g	..	n	Mar 2004	2,999	ebay.com
2.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.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	550	n	Sep 2009	7,999	ebay.com
9.		Nikon D40	124 mm	94 mm	64 mm	522 g	470	n	Nov 2006	499	ebay.com
10.		Nikon D50	133 mm	102 mm	76 mm	620 g	400	n	Apr 2005	749	ebay.com
11.		Nikon D70s	140 mm	111 mm	78 mm	679 g	500	n	Apr 2005	899	ebay.com
12.		Nikon D70	140 mm	111 mm	78 mm	679 g	400	n	Jan 2004	999	ebay.com
13.		Sony A7R IVA	129 mm	96 mm	78 mm	665 g	670	Y	Apr 2021	3,499	amazon.com
14.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	amazon.com
15.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	4,499	amazon.com
16.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
17.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	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 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 R-D1 was launched at a somewhat lower price (by 14 percent) than the A7R IV, which makes it more attractive for photographers on a tight budget. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the 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 Epson R-D1 features an APS-C sensor and the Sony A7R IV a full frame sensor. The sensor area in the A7R IV is 130 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 60.2MP, the A7R IV offers a higher resolution than the R-D1 (6MP), but the A7R IV has smaller individual pixels (pixel pitch of 3.76μm versus 7.85μm for the R-D1). Yet, the A7R IV is a much more recent model (by 15 years and 4 months) than the R-D1, 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 the A7R IV has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A7R IV implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R IV for good quality output (200 dots per inch) amounts to 47.5 x 31.7 inches or 120.7 x 80.5 cm, for very good quality (250 dpi) 38 x 25.3 inches or 96.6 x 64.4 cm, and for excellent quality (300 dpi) 31.7 x 21.1 inches or 80.5 x 53.6 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 A7R IV has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

Unlike the R-D1, the A7R IV has the capacity to capture high quality composite images (241MP) by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

The Epson R-D1 has a native sensitivity range from ISO 200 to ISO 1600. The corresponding ISO settings for the Sony Alpha A7R IV are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.

In terms of underlying technology, the R-D1 is build around a CCD sensor, while the A7R IV 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.

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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar 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 A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
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 D40	APS-C	6.0	3008	2000	none	21.0	11.0	561	56
10.		Nikon D50	APS-C	6.0	3008	2000	none	20.9	10.8	560	55
11.		Nikon D70s	APS-C	6.0	3008	2000	none	20.4	10.3	529	50
12.		Nikon D70	APS-C	6.0	3008	2000	none	20.4	10.3	529	50
13.		Sony A7R IVA	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
14.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
15.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
16.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
17.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
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 A7R IV indeed provides for movie recording, while the R-D1 does not. The highest resolution format that the A7R IV can use is 4K/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the A7R IV has an electronic viewfinder (5760k 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 following table reports on some other key feature differences and similarities of the Epson R-D1, the Sony A7R IV, 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.		Epson R-D1	optical	n	2.0 / 235	fixed	n	1/2000s	1.0/s	n	n
2.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
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 D40	optical	n	2.5 / 230	fixed	n	1/4000s	2.5/s	Y	n
10.		Nikon D50	optical	n	2.0 / 130	fixed	n	1/4000s	2.5/s	Y	n
11.		Nikon D70s	optical	n	2.0 / 130	fixed	n	1/8000s	3.0/s	Y	n
12.		Nikon D70	optical	n	1.8 / 130	fixed	n	1/8000s	3.0/s	Y	n
13.		Sony A7R IVA	5760	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
14.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
15.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
16.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
17.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
Note: *) 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 A7R IV 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 A7R IV 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 Sony A7R IV 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 R-D1 writes its imaging data to SDHC cards, while the A7R IV uses SDXC cards. The A7R IV features dual card slots, which can be very useful in case a memory card fails. In contrast, the R-D1 only has one slot. The A7R IV supports UHS-II cards (on both slots), 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 A7R IV 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 A7R IV	Y	stereo / mono	Y	Y	micro	3.1	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 D40	Y	- / -	-	-	-	2.0	-	-	-
10.		Nikon D50	Y	- / -	-	-	-	2.0	-	-	-
11.		Nikon D70s	Y	- / -	-	-	-	2.0	-	-	-
12.		Nikon D70	Y	- / -	-	-	-	1.0	-	-	-
13.		Sony A7R IVA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
14.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
15.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
16.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
17.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y

It is notable that the A7R IV 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.

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Both the R-D1 and the A7R IV have been discontinued, but can regularly be found used on ebay. The A7R IV was replaced by the Sony A7R V, while the R-D1 does not have a direct successor. Further information on the features and operation of the R-D1 and A7R IV can be found, respectively, in the Epson R-D1 Manual (free pdf) or the online Sony A7R IV Manual.

Review summary

So how do things add up? Which of the two cameras – the Epson R-D1 or the Sony A7R IV – 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 Epson R-D1:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• More affordable: Was introduced into a lower priced segment (14 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in March 2004).

Reasons to prefer the Sony Alpha A7R IV:

• More detail: Has more megapixels (60.2 vs 6MP), which boosts linear resolution by 216%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• 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.
• 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 (1440k 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.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/2000s) to freeze action.
• Faster burst: Shoots at higher frequency (10 vs 1 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.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• 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.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• Faster buffer clearing: Supports Ultra High Speed (UHS-II) SDXC cards on both slots.
• More modern: Reflects 15 years and 4 months of technical progress since the R-D1 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A7R IV is the clear winner of the contest (27 : 4 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 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.

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 R-D1 or the A7R IV. 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 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 A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.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 D40	..	81/100	..	+ +	o	4.5/5	Nov 2006	499	ebay.com
10.		Nikon D50	..	78/100	..	+ +	4/5	4.5/5	Apr 2005	749	ebay.com
11.		Nikon D70s	..	..	..	..	..	5/5	Apr 2005	899	ebay.com
12.		Nikon D70	..	..	..	+ +	..	..	Jan 2004	999	ebay.com
13.		Sony A7R IVA	5/5	+	4.5/5	91/100	4.5/5	5/5	Apr 2021	3,499	amazon.com
14.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
15.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	4,499	amazon.com
16.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
17.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	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. 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, please note that some of the review sites have changed their methodology and reporting over time.

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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 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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