Olympus E-M1 vs Sony A55

Let's look closer at the Olympus E-M1 and Sony A55, former is a Pro Mirrorless while the other is a Entry-Level DSLR by competitors Olympus and Sony. The resolution of the E-M1 (16MP) and the A55 (16MP) is fairly well matched but the E-M1 (Four Thirds) and A55 (APS-C) have totally different sensor measurements.

Photography Glossary

The E-M1 was announced 3 years after the A55 which is quite a significant difference as far as tech is concerned. Both of these cameras have different body design with the Olympus E-M1 being a SLR-style mirrorless camera and the Sony A55 being a Compact SLR camera.

Before delving straight to a in depth comparison, here is a concise overview of how the E-M1 scores vs the A55 in relation to portability, imaging, features and an overall mark.

Here is a sample of the gallery pictures for Olympus OM-D E-M1 & Sony SLT-A55. The whole galleries are available at Olympus E-M1 Gallery & Sony A55 Gallery.

If you are aiming to travel with your camera often, you'll have to think about its weight and proportions. The Olympus E-M1 offers outside measurements of 130mm x 94mm x 63mm (5.1" x 3.7" x 2.5") having a weight of 497 grams (1.10 lbs) while the Sony A55 has measurements of 124mm x 92mm x 85mm (4.9" x 3.6" x 3.3") along with a weight of 500 grams (1.10 lbs).

Take a look at the Olympus E-M1 and Sony A55 in our completely new Camera plus Lens Size Comparison Tool.

Remember, the weight of an ILC will vary dependant on the lens you are working with at that time. Following is a front view scale comparison of the E-M1 compared to the A55.

Looking at size and weight, the portability rating of the E-M1 and A55 is 71 and 67 respectively.

Generally, its difficult to see the difference between sensor dimensions just by looking at specifications. The image below will give you a better sense of the sensor sizing in the E-M1 and A55.

Plainly, each of the cameras provide the same MP but not the same sensor dimensions. The E-M1 comes with the tinier sensor which will make obtaining shallow depth of field more challenging. The newer E-M1 is going to have an edge when it comes to sensor tech.