Equiv. Aperture 101

Understand how sensor size relates to depth of field, bokeh, and total light.

Why Does Mobile F1.8 Lack Bokeh?

Manufacturers often market "F1.8" or "F1.4", but the depth of field (bokeh) is nowhere near a full-frame F4.0. This is because "Physical Aperture" only determines light intensity per unit area. "Depth of Field" and "Total Light Intake" are determined by "Equivalent Aperture".

The Formula

Equiv. Aperture = F-Stop × Crop Factor

* Crop Factor = Full Frame Diagonal / Sensor Diagonal

Interactive Bokeh Simulator

Equiv. Aperture

F1.8

Physical Aperturef/1.8

f/1.4f/5.6

Crop Factor1.0x

1x (FF)2.7x (1″)6x (Tele)