Olympus E-M1 II vs Pentax K-S1

On this page, we are evaluating the Olympus E-M1 II vs Pentax K-S1, one being a Pro Mirrorless and the other is a Advanced DSLR by rivals Olympus and Pentax. The image resolution of the E-M1 II (20MP) and the K-S1 (20MP) is very well matched but the E-M1 II (Four Thirds) and K-S1 (APS-C) offer totally different sensor size.

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The E-M1 II was revealed 2 years later than the K-S1 and that is quite a sizable gap as far as tech is concerned. Both of the cameras have different body design with the Olympus E-M1 II being a SLR-style mirrorless camera and the Pentax K-S1 being a Mid-size SLR camera.

Before getting right into a detailed comparison, here is a simple introduction of how the E-M1 II matches up against the K-S1 when it comes to portability, imaging, features and an overall grade.

The following is a sample of the gallery pics for Olympus OM-D E-M1 Mark II and Pentax K-S1. The full galleries are provided at Olympus E-M1 II Gallery and Pentax K-S1 Gallery.

In case you're intending to lug around your camera, you are going to need to factor its weight and dimensions. The Olympus E-M1 II offers outside dimensions of 134mm x 91mm x 67mm (5.3" x 3.6" x 2.6") accompanied by a weight of 574 grams (1.27 lbs) whilst the Pentax K-S1 has dimensions of 121mm x 93mm x 70mm (4.8" x 3.7" x 2.8") along with a weight of 558 grams (1.23 lbs).

Look at the Olympus E-M1 II vs Pentax K-S1 in the new Camera and Lens Size Comparison Tool.

Keep in mind, the weight of an Interchangeable Lens Camera will vary dependant on the lens you use at that moment. The following is a front view sizing comparison of the E-M1 II compared to the K-S1.

Taking into consideration size and weight, the portability score of the E-M1 II and K-S1 is 68 and 69 respectively.

Generally, it can be tough to envision the contrast between sensor measurements purely by reading through technical specs. The photograph here will give you a stronger sense of the sensor sizes in the E-M1 II and K-S1.

As you have seen, each of the cameras provide the same MP but not the same sensor measurements. The E-M1 II provides the tinier sensor which should make achieving shallow DOF more challenging. The more recent E-M1 II will have an advantage with regard to sensor tech.