Vertical Angle of View = 2 × arctan(Format_Vertical / (2 × Focal_Length)) Dimensionless Blur Accumulation (2 m behind focus) = (1/L) ∫[s to s+L] (CoC(distance) / c_format) d(distance), L=2000 mm
Y-axis shows the average blur in “CoC tolerances” over the 2 m background; unitless and comparable across formats.
This tool compares background blur characteristics across different camera formats using a thin-lens model.
The graph shows the average normalized blur behind your subject (over 2 meters), in units of each format’s Circle of Confusion tolerance (dimensionless, comparable).
The 35mm-equivalent slider targets a vertical angle of view, using a 35mm full frame as reference.
As this tool was developed for getting a feel for environmental portraits across formats, the calculations (and the equivalency across film formats) differs between vertical and horizontal orientation. The usual equivalency calculations use film diagonals as the measure, this one uses the vertical angle of view and is thus more precise for portraits.
📱 Camera Orientation
🔧 Aperture Controls for Selected Formats
1.75 m
50 mm (35.0°)
Select Film/Sensor Formats to Display
Choose which format curves to show on the graph:
🔍 Blur accumulation for 2m behind subject
Circle radius ∝ average normalized blur (unitless) over 2 m behind focus.
Labels show focal length to achieve the selected vertical angle and the normalized blur value (no decimal point).
💡 Understanding the Graph
Horizontal axis: Vertical angle of view in degrees (log scale, from 100° to 3°).
Vertical axis: Average normalized CoC over 2 m behind the focused subject: (1/L) ∫ (CoC/c) d(distance). Dimensionless, displayed without decimal point.
Comparability: Values are unitless “CoC tolerance units,” comparable across formats and settings.
Apertures: Each format has its own aperture control (f/0.6 to f/16).
35mm equivalent slider: Uses 24 mm vertical for landscape, 36 mm vertical for portrait.
Orientation switch: Portrait uses sensor width as the vertical dimension; landscape uses height.
Physics-based: Thin-lens model with exact defocus blur integration; DoF info moved out of sliders per request.