Compare real-world fit, not spreadsheet noise.
Pick up to four products and tune the verdict around travel, hybrid work, wildlife, resale safety or pure value. GearAtlas weighs carry size, ecosystem cost, market timing and ownership risk in one calm decision surface.
Visual
Estimated
Ranked
Pentax K-3 Mark III
APS-C / 620g
Sony A7 III
Full-frame / 620g
Workflow lens
Sony A7 III is the stronger fit for travel and everyday carry.
Sony A7 III leads on video readiness by 26 points.
Sony A7 III leads on AF confidence by 6 points.
Sony A7 III leads on resale strength by 6 points.
Camera size studio
Relative body dimensions
Front, back and top views are drawn from external dimensions so the size relationship stays proportional.
View
Mode
Pentax K-3 Mark III
Front view / 132 x 92mm
132 x 92 x 72mm
Sony A7 III
Front view / 132 x 92mm
132 x 92 x 72mm
Width
Height
Depth
Weight
External dimensions and carry delta
Pentax K-3 Mark III and Sony A7 III share the same external size profile in the current data model.
Pentax K-3 Mark III
Sony A7 III
Class benchmarks
Sensor comparison
Sensor size to scale
×1.53 crop
×1 crop
Full-frame captures ~2.4× the sensor area of APS-C, a real low-light and depth-of-field edge.
Decision matrix
Scores tuned for travel
Highlighted specs
Only specs that change the decision
Sensor
25.7MP APS-C
Sensor
24.2MP full-frame BSI
Viewfinder
Optical pentaprism
Community comparison
Owner consensus · not specsCommunity comparison appears once owners vote on these products — 6 more votes across the pair will unlock it.