Olympus E-M1 vs Pentax K-S1

Here, we are looking at the Olympus E-M1 and Pentax K-S1, one being a Pro Mirrorless and the other is a Advanced DSLR by competitors Olympus and Pentax. The image resolution of the E-M1 (16MP) and the K-S1 (20MP) is very well matched but the E-M1 (Four Thirds) and K-S1 (APS-C) provide totally different sensor sizes.

Photography Glossary

The E-M1 was launched 10 months before the K-S1 and they are both of a similar generation. The two cameras feature different body design with the Olympus E-M1 being a SLR-style mirrorless camera and the Pentax K-S1 being a Mid-size SLR camera.

Before we go right into a complete comparison, here is a concise synopsis of how the E-M1 grades against the K-S1 in relation to portability, imaging, features and an overall rating.

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

If you are looking to carry your camera, you need to consider its weight and volume. The Olympus E-M1 offers physical dimensions of 130mm x 94mm x 63mm (5.1" x 3.7" x 2.5") accompanied by a weight of 497 grams (1.10 lbs) while the Pentax K-S1 has sizing 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 and Pentax K-S1 in the new Camera with Lens Size Comparison Tool.

Remember, the weight of an Interchangeable Lens Camera will differ based on the lens you are utilising during that time. Below is a front view scale comparison of the E-M1 vs the K-S1.

Considering size and weight, the portability grade of the E-M1 and K-S1 is 71 and 69 respectively.

Generally, it can be difficult to visualise the gap between sensor sizing simply by checking specs. The graphic underneath should give you a stronger sense of the sensor dimensions in the E-M1 and K-S1.

All in all, the 2 cameras come with different megapixel count and different sensor sizing. The E-M1 due to its tinier sensor will make shooting shallower DOF more challenging and the Pentax K-S1 will resolve greater detail utilizing its extra 4MP. Greater resolution will also make it easier to crop photos a good deal more aggressively. The older E-M1 is going to be behind in sensor innovation.