AperSim: Depth of Field Visualizer

Camera Settings

Sensor Size

Aperture (f-stop): f/2.8

Focal Length: 50mm

Subject Distance: 3.0m

Near Limit: --

Far Limit: --

Total DoF: --

Hyperfocal: --

Understanding Depth of Field

Depth of field (DoF) is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. Photographers use this optical effect to guide the viewer's eye. A shallow depth of field isolates a subject against a blurred background, which is common in portraiture and wildlife photography. A deep depth of field keeps everything sharp from the foreground to the horizon, which is necessary for landscape and architectural photography.

The Three Core Variables

Three main settings interact to determine exactly how much of your scene is within the completely sharp focal plane:

Aperture (f-stop): The size of the opening in the lens. A low f-number (like f/1.8) means a wide opening, resulting in a thin slice of focus. A high f-number (like f/16) narrows the opening, expanding the distance that stays sharp.
Focal Length: The magnification of the lens. Longer focal lengths (like 85mm or 200mm) compress the space and appear to create a much shallower depth of field compared to wide-angle lenses (like 24mm).
Subject Distance: How close the physical camera is to the thing you are focusing on. Getting closer to your subject significantly drops the background rapidly out of focus.

Common Assumptions and Sensor Sizes

Our visualizer uses a standard mathematical constant known as the "circle of confusion" to determine when a blurry point of light appears sharp to the human eye. This circle varies by the physical size of your camera's image sensor. A Full Frame (35mm format) sensor requires a different calculation compared to an APS-C crop sensor or a Micro Four Thirds sensor. By altering the sensor size in the simulator, you can see how crop factor changes equivalent blur and hyperfocal constraints.

Frequently Asked Questions

What is the hyperfocal distance?

The hyperfocal distance is the exact point of focus that maximizes your depth of field. If you manually focus your lens exactly at that distance, everything from half that distance to infinity will appear sharp in your final image. This is a crucial technique for landscape photographers.

Why does the visualizer warn about diffraction?

While stopping down your aperture (using higher numbers like f/16 or f/22) increases your mathematical depth of field, it introduces an optical side-effect called diffraction. Light rays bend as they pass through the tiny aperture hole, causing the entire image to lose microscopic sharpness, even within the focal plane.

Does this work perfectly for all lenses?

This simulator calculates theoretical depth of field using the standard optical formulas. Real-world lenses have specific characteristics—like optical curvature, astigmatism, and unique iris shapes—that change how background blur (bokeh) visually renders. Use this as a mathematical guide, not an absolute guarantee.