Olympus E-M5 III vs Pentax 645Z

On this page, we are evaluating the Olympus E-M5 III versus Pentax 645Z, one is a Advanced Mirrorless and the other is a Pro DSLR by manufacturers Olympus and Pentax. There exists a huge gap among the resolutions of the E-M5 III (20MP) and 645Z (51MP) and the E-M5 III (Four Thirds) and 645Z (Medium format) have different sensor size.

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The E-M5 III was revealed 5 years after the 645Z which is a fairly significant gap as far as camera technology is concerned. Each of these cameras have different body design with the Olympus E-M5 III being a SLR-style mirrorless camera and the Pentax 645Z being a Large SLR camera.

Before delving right into a in depth comparison, here is a brief summary of how the E-M5 III matches up against the 645Z with respect to portability, imaging, features and an overall mark.

Below is a sample of the gallery pictures for Olympus OM-D E-M5 III and Pentax 645Z. The full galleries are viewable at Olympus E-M5 III Gallery and Pentax 645Z Gallery.

If you are looking to travel with your camera frequently, you're going to have to think about its weight and measurements. The Olympus E-M5 III has got outer measurements of 125mm x 85mm x 50mm (4.9" x 3.3" x 2.0") accompanied by a weight of 414 grams (0.91 lbs) whilst the Pentax 645Z has proportions of 156mm x 117mm x 123mm (6.1" x 4.6" x 4.8") accompanied by a weight of 1550 grams (3.42 lbs).

Check the Olympus E-M5 III versus Pentax 645Z in the new Camera and Lens Size Comparison Tool.

Do not forget, the weight of an Interchangeable Lens Camera will differ dependant on the lens you are working with at that time. Following is a front view dimension comparison of the E-M5 III compared to the 645Z.

Taking into account dimensions and weight, the portability grade of the E-M5 III and 645Z is 80 and 49 respectively.

More often than not, its hard to picture the difference in sensor dimensions purely by going through specs. The pic here will offer you a better sense of the sensor sizing in the E-M5 III and 645Z.

All in all, each of the cameras provide different megapixel count and different sensor dimensions. The E-M5 III using its smaller sensor is going to make getting shallower depth of field trickier and the Pentax 645Z will provide extra detail because of its extra 31MP. Greater resolution will also let you crop photos more aggressively. The more recent E-M5 III provides a benefit in sensor tech.