🔬 Interactive Circle of Confusion (CoC) Calculator

CoC = (f²/N) × |1/S - 1/U|
f: focal length (mm), N: aperture, S: focus distance (mm), U: object distance (mm)
This tool lets you explore the behavior of Circle of Confusion (CoC) and the associated perceived sharpness and bokeh across formats and focal lengths. The colorful horizontal format lines in the graph correspond to the accepted and acceptable CoC in each format. Below the line the image will be perceived as sharp - above as soft. Settings like focal length, aperture and focus distance are set across formats. In the viewfinder preview below you can see a simulation of how your focus distance and angle of view would look like with an average person as a subject. In this case the distance from the camera to the person is the same as focus distance.
50mm
f/2.8
5.00m

Select Film/Sensor Formats to Display

Choose which format lines to show on the graph:

📷 Viewfinder Preview

Focus: 5.00m | Focal Length: 50mm | Subject: 175cm human

💡 Understanding the Graph