Olympus E-M5 II vs Pentax K-S1
The Olympus OM-D E-M5 Mark II and the Pentax K-S1 are two digital cameras that were officially introduced, respectively, in February 2015 and August 2014. The E-M5 II is a mirrorless interchangeable lens camera, while the K-S1 is a DSLR. The cameras are based on a Four Thirds (E-M5 II) and an APS-C (K-S1) sensor. The Olympus has a resolution of 15.9 megapixels, whereas the Pentax provides 20 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.

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Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus OM-D E-M5 Mark II and the Pentax K-S1? 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 Olympus E-M5 II and the Pentax K-S1 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.
The E-M5 II can be obtained in two different colors (black, silver), while the K-S1 is available in four color-versions (black, grey, orange, white).



If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-S1 is notably larger (7 percent) than the Olympus E-M5 II. Moreover, the K-S1 is markedly heavier (19 percent) than the E-M5 II. It is worth mentioning in this context that the E-M5 II is splash and dust resistant, while the K-S1 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-M5 II gets 310 shots out of its Olympus BLN-1 battery, while the K-S1 can take 410 images on a single charge of its Pentax D-LI109 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.

| Camera Model |
Camera Width |
Camera Height |
Camera Depth |
Camera Weight |
Battery Life |
Weather Sealing |
Camera Launch |
Launch Price |
Street Price |
||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Olympus E-M5 II | 124 mm | 85 mm | 45 mm | 469 g | 310 | Y | Feb 2015 | US$ 1 099 | ebay.com | |
| 2. | Pentax K-S1 | 121 mm | 93 mm | 70 mm | 558 g | 410 | n | Aug 2014 | US$ 749 | ebay.com | |
| 3. | Nikon D5300 | 125 mm | 98 mm | 76 mm | 480 g | 600 | n | Oct 2013 | US$ 799 | ebay.com | |
| 4. | Olympus E-M1 | 130 mm | 94 mm | 63 mm | 497 g | 350 | Y | Sep 2013 | US$ 1 399 | ebay.com | |
| 5. | Olympus E-M1 II | 134 mm | 91 mm | 67 mm | 574 g | 440 | Y | Sep 2016 | US$ 1 999 | ebay.com | |
| 6. | Olympus E-M5 | 122 mm | 89 mm | 43 mm | 425 g | 360 | Y | Feb 2012 | US$ 1 299 | ebay.com | |
| 7. | Olympus E-M5 III | 125 mm | 85 mm | 50 mm | 414 g | 310 | Y | Oct 2019 | US$ 1 199 | ebay.com | |
| 8. | Olympus E-M10 | 119 mm | 82 mm | 46 mm | 396 g | 320 | n | Jan 2014 | US$ 699 | ebay.com | |
| 9. | Olympus E-M10 II | 120 mm | 83 mm | 47 mm | 390 g | 320 | n | Aug 2015 | US$ 649 | ebay.com | |
| 10. | Olympus E-P5 | 122 mm | 69 mm | 37 mm | 420 g | 330 | n | May 2013 | US$ 999 | ebay.com | |
| 11. | Olympus PEN-F | 125 mm | 72 mm | 37 mm | 427 g | 330 | n | Jan 2016 | US$ 1 199 | ebay.com | |
| 12. | Panasonic G80 | 128 mm | 89 mm | 74 mm | 505 g | 330 | Y | Sep 2016 | US$ 899 | ebay.com | |
| 13. | Panasonic GX8 | 133 mm | 78 mm | 63 mm | 487 g | 330 | Y | Jul 2015 | US$ 1 199 | ebay.com | |
| 14. | Pentax K-3 | 131 mm | 100 mm | 77 mm | 800 g | 560 | Y | Oct 2013 | US$ 1 299 | ebay.com | |
| 15. | Pentax K-500 | 130 mm | 97 mm | 71 mm | 646 g | 710 | n | Jun 2013 | US$ 549 | ebay.com | |
| 16. | Pentax K-S2 | 123 mm | 91 mm | 73 mm | 678 g | 410 | Y | Feb 2015 | US$ 749 | ebay.com | |
| 17. | Sony A68 | 143 mm | 104 mm | 81 mm | 610 g | 540 | n | Nov 2015 | US$ 699 | ebay.com | |
| Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders. | |||||||||||
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 K-S1 was launched at a markedly lower price (by 32 percent) than the E-M5 II, which puts it into a different market segment. 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 tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 Olympus E-M5 II features a Four Thirds sensor and the Pentax K-S1 an APS-C sensor. The sensor area in the K-S1 is 63 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.5. The sensor in the E-M5 II has a native 4:3 aspect ratio, while the one in the K-S1 offers a 3:2 aspect.

With 20MP, the K-S1 offers a higher resolution than the E-M5 II (15.9MP), but the K-S1 nevertheless has larger individual pixels (pixel pitch of 4.28μm versus 3.76μm for the E-M5 II) due to its larger sensor. However, the E-M5 II is a somewhat more recent model (by 5 months) than the K-S1, and its sensor might 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 K-S1 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax K-S1 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-S1 for good quality output (200 dots per inch) amounts to 27.4 x 18.2 inches or 69.5 x 46.3 cm, for very good quality (250 dpi) 21.9 x 14.6 inches or 55.6 x 37.1 cm, and for excellent quality (300 dpi) 18.2 x 12.2 inches or 46.3 x 30.9 cm. The corresponding values for the Olympus E-M5 II are 23 x 17.3 inches or 58.5 x 43.9 cm for good quality, 18.4 x 13.8 inches or 46.8 x 35.1 cm for very good quality, and 15.4 x 11.5 inches or 39 x 29.3 cm for excellent quality prints.
Unlike the K-S1, the E-M5 II has the capacity to capture high quality composite images (40MP) 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 Olympus OM-D E-M5 Mark II has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 100-25600. The corresponding ISO settings for the Pentax K-S1 are ISO 100 to ISO 51200 (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.

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"). Of the two cameras under consideration, the K-S1 has a markedly higher DXO score than the E-M5 II (overall score 5 points higher), which will translate into better image quality. The advantage is based on 0.5 bits higher color depth, 0.5 EV in additional dynamic range, and 0.3 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.

| Camera Model |
Sensor Class |
Resolution (MP) |
Horiz. Pixels |
Vert. Pixels |
Video Format |
DXO Portrait |
DXO Landscape |
DXO Sports |
DXO Overall |
||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Olympus E-M5 II | Four Thirds | 15.9 | 4608 | 3456 | 1080/60p | 23.0 | 12.5 | 842 | 73 | |
| 2. | Pentax K-S1 | APS-C | 20.0 | 5472 | 3648 | 1080/30p | 23.5 | 13.0 | 1061 | 78 | |
| 3. | Nikon D5300 | APS-C | 24.0 | 6000 | 4000 | 1080/60p | 24.0 | 13.9 | 1338 | 83 | |
| 4. | Olympus E-M1 | Four Thirds | 15.9 | 4608 | 3456 | 1080/30p | 23.0 | 12.7 | 757 | 73 | |
| 5. | Olympus E-M1 II | Four Thirds | 20.2 | 5184 | 3888 | 4K/30p | 23.7 | 12.8 | 1312 | 80 | |
| 6. | Olympus E-M5 | Four Thirds | 15.9 | 4608 | 3456 | 1080/60i | 22.8 | 12.3 | 826 | 71 | |
| 7. | Olympus E-M5 III | Four Thirds | 20.2 | 5184 | 3888 | 4K/30p | 23.3 | 13.1 | 1324 | 76 | |
| 8. | Olympus E-M10 | Four Thirds | 15.9 | 4608 | 3456 | 1080/30p | 22.8 | 12.3 | 884 | 72 | |
| 9. | Olympus E-M10 II | Four Thirds | 15.9 | 4608 | 3456 | 1080/60p | 23.1 | 12.5 | 842 | 73 | |
| 10. | Olympus E-P5 | Four Thirds | 15.9 | 4608 | 3456 | 1080/30p | 22.8 | 12.4 | 895 | 72 | |
| 11. | Olympus PEN-F | Four Thirds | 20.2 | 5184 | 3888 | 1080/60p | 23.1 | 12.4 | 894 | 74 | |
| 12. | Panasonic G80 | Four Thirds | 15.8 | 4592 | 3448 | 4K/30p | 22.8 | 12.5 | 656 | 71 | |
| 13. | Panasonic GX8 | Four Thirds | 20.2 | 5184 | 3888 | 4K/30p | 23.5 | 12.6 | 806 | 75 | |
| 14. | Pentax K-3 | APS-C | 24.1 | 6016 | 4000 | 1080/60i | 23.7 | 13.4 | 1216 | 80 | |
| 15. | Pentax K-500 | APS-C | 16.1 | 4928 | 3264 | 1080/30p | 23.7 | 13.1 | 1087 | 79 | |
| 16. | Pentax K-S2 | APS-C | 20.0 | 5472 | 3648 | 1080/30p | 23.6 | 12.9 | 1514 | 79 | |
| 17. | Sony A68 | APS-C | 24.0 | 6000 | 4000 | 1080/60i | 24.1 | 13.5 | 701 | 79 | |
| 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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the E-M5 II provides a higher frame rate than the K-S1. It can shoot video footage at 1080/60p, while the Pentax is limited to 1080/30p.
Feature comparison
Beyond body and sensor, cameras can and do differ across a range of features. For example, the E-M5 II has an electronic viewfinder (2360k dots), while the K-S1 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the E-M5 II has a higher magnification than the one of the K-S1 (0.74x vs 0.63x), 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-M5 II, the Pentax K-S1, and comparable cameras.

| 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-M5 II | 2360 | n | 3.0 / 1037 | swivel | Y | 1/8000s | 10.0/s | n | Y | |
| 2. | Pentax K-S1 | optical | n | 3.0 / 921 | fixed | n | 1/6000s | 5.4/s | Y | Y | |
| 3. | Nikon D5300 | optical | n | 3.2 / 1037 | swivel | n | 1/4000s | 5.0/s | Y | n | |
| 4. | Olympus E-M1 | 2360 | n | 3.0 / 1037 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
| 5. | Olympus E-M1 II | 2360 | n | 3.0 / 1037 | swivel | Y | 1/8000s | 18.0/s | n | Y | |
| 6. | Olympus E-M5 | 1440 | n | 3.0 / 610 | tilting | Y | 1/4000s | 9.0/s | n | Y | |
| 7. | Olympus E-M5 III | 2360 | n | 3.0 / 1040 | swivel | Y | 1/8000s | 10.0/s | n | Y | |
| 8. | Olympus E-M10 | 1440 | n | 3.0 / 1037 | tilting | Y | 1/4000s | 8.0/s | Y | Y | |
| 9. | Olympus E-M10 II | 2360 | n | 3.0 / 1040 | tilting | Y | 1/4000s | 8.0/s | Y | Y | |
| 10. | Olympus E-P5 | optional | n | 3.0 / 1037 | tilting | Y | 1/8000s | 9.0/s | Y | Y | |
| 11. | Olympus PEN-F | 2360 | n | 3.0 / 1037 | swivel | Y | 1/8000s | 10.0/s | n | Y | |
| 12. | Panasonic G80 | 2360 | n | 3.0 / 1040 | swivel | Y | 1/4000s | 9.0/s | Y | Y | |
| 13. | Panasonic GX8 | 2360 | n | 3.0 / 1040 | swivel | Y | 1/8000s | 10.0/s | n | Y | |
| 14. | Pentax K-3 | optical | Y | 3.2 / 1037 | fixed | n | 1/8000s | 8.3/s | Y | Y | |
| 15. | Pentax K-500 | optical | n | 3.0 / 921 | fixed | n | 1/6000s | 6.0/s | Y | Y | |
| 16. | Pentax K-S2 | optical | n | 3.0 / 921 | swivel | n | 1/6000s | 5.4/s | Y | Y | |
| 17. | Sony A68 | 1440 | Y | 2.7 / 460 | tilting | n | 1/4000s | 8.0/s | Y | 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 E-M5 II has a touchscreen, while the K-S1 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.
The E-M5 II has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the K-S1 does not have a selfie-screen.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 E-M5 II 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 Olympus E-M5 II 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 E-M5 II and the K-S1 write their files to SDXC cards. The E-M5 II supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the K-S1 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 Olympus OM-D E-M5 Mark II and Pentax K-S1 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

| Camera Model |
Hotshoe Port |
Internal Mic / Speaker |
Microphone Port |
Headphone Port |
HDMI Port |
USB Port |
WiFi Support |
NFC Support |
Bluetooth Support |
||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Olympus E-M5 II | Y | stereo / mono | Y | - | micro | 2.0 | Y | - | - | |
| 2. | Pentax K-S1 | Y | stereo / mono | - | - | micro | 2.0 | - | - | - | |
| 3. | Nikon D5300 | Y | stereo / mono | Y | - | mini | 2.0 | Y | - | - | |
| 4. | Olympus E-M1 | Y | stereo / mono | Y | - | micro | 2.0 | Y | - | - | |
| 5. | Olympus E-M1 II | Y | stereo / mono | Y | Y | micro | 3.0 | Y | - | - | |
| 6. | Olympus E-M5 | Y | stereo / mono | - | - | mini | 2.0 | - | - | - | |
| 7. | Olympus E-M5 III | Y | stereo / mono | Y | - | micro | 2.0 | Y | - | Y | |
| 8. | Olympus E-M10 | Y | stereo / mono | - | - | micro | 2.0 | Y | - | - | |
| 9. | Olympus E-M10 II | Y | stereo / mono | - | - | micro | 2.0 | Y | - | - | |
| 10. | Olympus E-P5 | Y | stereo / mono | - | - | micro | 2.0 | Y | - | - | |
| 11. | Olympus PEN-F | Y | stereo / mono | - | - | micro | 2.0 | Y | - | - | |
| 12. | Panasonic G80 | Y | stereo / mono | Y | - | micro | 2.0 | Y | - | - | |
| 13. | Panasonic GX8 | Y | stereo / mono | Y | - | micro | 2.0 | Y | Y | - | |
| 14. | Pentax K-3 | Y | mono / mono | Y | Y | mini | 3.0 | - | - | - | |
| 15. | Pentax K-500 | Y | mono / mono | - | - | - | 2.0 | - | - | - | |
| 16. | Pentax K-S2 | Y | mono / mono | Y | - | micro | 2.0 | Y | Y | - | |
| 17. | Sony A68 | Y | stereo / mono | Y | - | micro | 2.0 | - | - | - |
It is notable that the E-M5 II has a microphone port, which is missing on the K-S1. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.
Studio photographers will appreciate that the Olympus E-M5 II (unlike the K-S1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the E-M5 II and the K-S1 have been discontinued, but can regularly be found used on ebay. The K-S1 was replaced by the Pentax K-S2, while the E-M5 II was followed by the Olympus E-M5 III. Further information on the features and operation of the E-M5 II and K-S1 can be found, respectively, in the Olympus E-M5 II Manual (free pdf) or the online Pentax K-S1 Manual.
Review summary
So what is the bottom line? Is the Olympus E-M5 II better than the Pentax K-S1 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Olympus OM-D E-M5 Mark II:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better video: Provides higher movie framerates (1080/60p versus 1080/30p).
- Better sound: Can connect to an external microphone for higher quality sound recording.
- More framing info: Has an electronic viewfinder that displays shooting data.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.74x vs 0.63x).
- More detailed LCD: Has a higher resolution rear screen (1037k vs 921k dots).
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/6000s) to freeze action.
- Faster burst: Shoots at higher frequency (10 vs 5.4 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.
- Less heavy: Is lighter (by 89g or 16 percent) and hence easier to carry around.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Is somewhat more recent (announced 5 months after the K-S1).

Reasons to prefer the Pentax K-S1:
- More detail: Has more megapixels (20 vs 15.9MP), which boosts linear resolution by 14%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better image quality: Scores markedly higher (5 points) in the DXO overall evaluation.
- Better low-light sensitivity: Can shoot in dim conditions (0.3 stops ISO advantage).
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Longer lasting: Gets more shots (410 versus 310) out of a single battery charge.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- More affordable: Was introduced into a lower priced category (32 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in August 2014).
If the count of individual advantages (bullet points above) is taken as a guide, the E-M5 II is the clear winner of the match-up (21 : 9 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 Olympus E-M5 II and the Pentax K-S1 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the E-M5 II and the K-S1 in practical situations. 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 why hands-on reviews by experts are important. The following table reports the overall ratings of the cameras as published by some of the major 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.

| Camera Model |
AP score |
CL score |
DCW score |
DPR score |
EPZ score |
PB score |
Camera Launch |
Launch Price |
Street Price |
||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Olympus E-M5 II | 5/5 | + + | 4.5/5 | 81/100 | 5/5 | 5/5 | Feb 2015 | US$ 1 099 | ebay.com | |
| 2. | Pentax K-S1 | 4/5 | .. | .. | .. | 4.5/5 | 4/5 | Aug 2014 | US$ 749 | ebay.com | |
| 3. | Nikon D5300 | 4/5 | + + | .. | 79/100 | 4.5/5 | 4.5/5 | Oct 2013 | US$ 799 | ebay.com | |
| 4. | Olympus E-M1 | 5/5 | + + | .. | 84/100 | 4.5/5 | 4.5/5 | Sep 2013 | US$ 1 399 | ebay.com | |
| 5. | Olympus E-M1 II | 5/5 | + + | 5/5 | 85/100 | 4.5/5 | 4.5/5 | Sep 2016 | US$ 1 999 | ebay.com | |
| 6. | Olympus E-M5 | 4/5 | + + | .. | 80/100 | 4.5/5 | 5/5 | Feb 2012 | US$ 1 299 | ebay.com | |
| 7. | Olympus E-M5 III | 5/5 | + | 5/5 | 82/100 | 4.5/5 | 4.5/5 | Oct 2019 | US$ 1 199 | ebay.com | |
| 8. | Olympus E-M10 | 4/5 | .. | .. | 80/100 | 5/5 | 5/5 | Jan 2014 | US$ 699 | ebay.com | |
| 9. | Olympus E-M10 II | 4.5/5 | + + | .. | 80/100 | 5/5 | 5/5 | Aug 2015 | US$ 649 | ebay.com | |
| 10. | Olympus E-P5 | 5/5 | + + | .. | 78/100 | 4.5/5 | 5/5 | May 2013 | US$ 999 | ebay.com | |
| 11. | Olympus PEN-F | .. | .. | 4/5 | 82/100 | 4.5/5 | 5/5 | Jan 2016 | US$ 1 199 | ebay.com | |
| 12. | Panasonic G80 | .. | + + | .. | 84/100 | 5/5 | 4.5/5 | Sep 2016 | US$ 899 | ebay.com | |
| 13. | Panasonic GX8 | 5/5 | + | .. | 82/100 | 4.5/5 | 4.5/5 | Jul 2015 | US$ 1 199 | ebay.com | |
| 14. | Pentax K-3 | 4/5 | .. | .. | 83/100 | 5/5 | 5/5 | Oct 2013 | US$ 1 299 | ebay.com | |
| 15. | Pentax K-500 | .. | .. | .. | .. | 4.5/5 | 4.5/5 | Jun 2013 | US$ 549 | ebay.com | |
| 16. | Pentax K-S2 | 4.5/5 | .. | .. | .. | 5/5 | 4.5/5 | Feb 2015 | US$ 749 | ebay.com | |
| 17. | Sony A68 | 3/5 | .. | .. | .. | 4/5 | 4/5 | Nov 2015 | US$ 699 | 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 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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
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Specifications: Olympus E-M5 II vs Pentax K-S1
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
| Camera Model | Olympus E-M5 II | Pentax K-S1 |
|---|---|---|
| Camera Type | Mirrorless system camera | Digital single lens reflex |
| Camera Lens | Micro Four Thirds lenses | Pentax K mount lenses |
| Launch Date | February 2015 | August 2014 |
| Launch Price | USD 1,099 | USD 749 |
| Sensor Specs | Olympus E-M5 II | Pentax K-S1 |
| Sensor Technology | CMOS | CMOS |
| Sensor Format | Four Thirds Sensor | APS-C Sensor |
| Sensor Size | 17.3 x 13.0 mm | 23.5 x 15.6 mm |
| Sensor Area | 224.9 mm2 | 366.6 mm2 |
| Sensor Diagonal | 21.6 mm | 28.2 mm |
| Crop Factor | 2.0x | 1.5x |
| Sensor Resolution | 15.9 Megapixels | 20 Megapixels |
| Image Resolution | 4608 x 3456 pixels | 5472 x 3648 pixels |
| Pixel Pitch | 3.76 μm | 4.28 μm |
| Pixel Density | 7.08 MP/cm2 | 5.45 MP/cm2 |
| Moiré control | Anti-Alias filter | no AA filter |
| Movie Capability | 1080/60p Video | 1080/30p Video |
| ISO Setting | 200 - 25,600 ISO | 100 - 51,200 ISO |
| ISO Boost | 100 - 25,600 ISO | no Enhancement |
| Image Processor | TruePic VII | PRIME MII |
| DXO Sensor Quality (score) | 73 | 78 |
| DXO Color Depth (bits) | 23.0 | 23.5 |
| DXO Dynamic Range (EV) | 12.5 | 13.0 |
| DXO Low Light (ISO) | 842 | 1061 |
| Screen Specs | Olympus E-M5 II | Pentax K-S1 |
| Viewfinder Type | Electronic viewfinder | Optical viewfinder |
| Viewfinder Field of View | 100% | 100% |
| Viewfinder Magnification | 0.74x | 0.63x |
| Viewfinder Resolution | 2360k dots | |
| LCD Framing | Live View | Live View |
| Rear LCD Size | 3.0inch | 3.0inch |
| LCD Resolution | 1037k dots | 921k dots |
| LCD Attachment | Swivel screen | Fixed screen |
| Touch Input | Touchscreen | no Touchscreen |
| Shooting Specs | Olympus E-M5 II | Pentax K-S1 |
| Focus System | Contrast-detect AF | Phase-detect AF |
| Manual Focusing Aid | Focus Peaking | Focus Peaking |
| Max Shutter Speed (mechanical) | 1/8000s | 1/6000s |
| Continuous Shooting | 10 shutter flaps/s | 5.4 shutter flaps/s |
| Electronic Shutter | up to 1/16000s | no E-Shutter |
| Time-Lapse Photography | Intervalometer built-in | no Intervalometer |
| Image Stabilization | In-body stabilization | In-body stabilization |
| Fill Flash | no On-Board Flash | Built-in Flash |
| Storage Medium | SDXC cards | SDXC cards |
| Single or Dual Card Slots | Single card slot | Single card slot |
| UHS card support | UHS-II | UHS-I |
| Connectivity Specs | Olympus E-M5 II | Pentax K-S1 |
| External Flash | Hotshoe | Hotshoe |
| Studio Flash | PC Sync socket | no PC Sync |
| USB Connector | USB 2.0 | USB 2.0 |
| HDMI Port | micro HDMI | micro HDMI |
| Microphone Port | External MIC port | no MIC socket |
| Wifi Support | Wifi built-in | no Wifi |
| Body Specs | Olympus E-M5 II | Pentax K-S1 |
| Environmental Sealing | Weathersealed body | not weather sealed |
| Battery Type | Olympus BLN-1 | Pentax D-LI109 |
| Battery Life (CIPA) | 310 shots per charge | 410 shots per charge |
| Body Dimensions |
124 x 85 x 45 mm (4.9 x 3.3 x 1.8 in) |
121 x 93 x 70 mm (4.8 x 3.7 x 2.8 in) |
| Camera Weight | 469 g (16.5 oz) | 558 g (19.7 oz) |

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