Pentax K-S1 vs Sony A7R III

Here is a in depth assessment of the Pentax K-S1 vs Sony A7R III, former being a Advanced DSLR while the latter is a Pro Mirrorless by competitors Pentax and Sony. There is a sizable difference between the image resolutions of the K-S1 (20MP) and A7R III (42MP) and the K-S1 (APS-C) and A7R III (Full frame) have totally different sensor size.

Photography Glossary

The K-S1 was launched 4 years before the A7R III and that is quite a significant difference as far as tech is concerned. Both of the cameras feature different body design with the Pentax K-S1 being a Mid-size SLR camera and the Sony A7R III being a SLR-style mirrorless camera.

Before getting straight to a thorough comparison, here is a simple synopsis of how the K-S1 scores versus the A7R III for portability, imaging, features and an overall rating.

Following is a preview of the gallery images for Pentax K-S1 & Sony Alpha A7R III. The complete galleries are available at Pentax K-S1 Gallery & Sony A7R III Gallery.

For anyone who is going to carry your camera, you have to take into account its weight and dimensions. The Pentax K-S1 features external measurements of 121mm x 93mm x 70mm (4.8" x 3.7" x 2.8") along with a weight of 558 grams (1.23 lbs) and the Sony A7R III has dimensions of 127mm x 96mm x 74mm (5.0" x 3.8" x 2.9") having a weight of 657 grams (1.45 lbs).

Contrast the Pentax K-S1 vs Sony A7R III in our newest Camera plus Lens Size Comparison Tool.

Remember that, the weight of an ILC will vary based on the lens you have attached at that moment. Underneath is a front view physical size comparison of the K-S1 against the A7R III.

Considering size and weight, the portability rating of the K-S1 and A7R III is 69 and 63 respectively.

Usually, it is very hard to envision the contrast between sensor sizing simply by checking a spec sheet. The photograph below will help offer you a far better sense of the sensor measurements in the K-S1 and A7R III.

Clearly, both cameras come with different megapixels and different sensor sizing. The K-S1 featuring a tinier sensor will make getting shallow DOF trickier and the Sony A7R III will give more detail utilizing its extra 22 Megapixels. Higher resolution will also let you crop shots a good deal more aggressively. The older K-S1 is going to be behind when it comes to sensor innovation.