Diffraction Calculatorv1.0.0

Diffraction is an optical phenomenon that limits the sharpness of photographs taken at small apertures. As a lens stops down to higher f-numbers, the Airy disk produced by light passing through the aperture grows larger. When the Airy disk exceeds the size of individual pixels on the sensor, the image begins to lose detail due to diffraction softening. Determine exactly where that threshold lies for any specific camera and lens combination, then choose the sharpest aperture for the shot.

• Select your camera from the Camera Preset dropdown, or enter a custom Sensor Width, Sensor Height, and Megapixels value manually. Inputs accept fractions (3/4), mixed numbers (5 1/16), and decimals.
• Enter your desired Aperture f-number. For example, enter 8 for f/8 or 16 for f/16.
• Review the results: Pixel Pitch shows the physical size of each pixel, Airy Disk Diameter shows the diffraction pattern size, and Diffraction Status indicates whether your chosen aperture is diffraction-limited.
• The Diffraction-Limited Aperture tells you the widest aperture at which diffraction begins to affect sharpness for your sensor.
• Open Settings to adjust the light wavelength (default 550 nm for green light), change the diffraction criterion strictness, or enable the step-by-step formula display.
• The Diffraction by Aperture table below the results shows Airy disk sizes across a range of common apertures so you can quickly compare diffraction impact at different settings.
• All inputs and settings persist automatically. Click Reset to restore defaults. Share configurations using URL query parameters.

Understanding diffraction limits is essential for photographers, optical engineers, and anyone who needs to maximize image sharpness. Knowing the sharpest usable aperture for a specific body and lens prevents unnecessary loss of resolution and informs decisions about depth of field versus diffraction trade-offs.

• Landscape Photography: Determine the optimal aperture for maximum depth of field without crossing the diffraction limit. A 45 MP full-frame camera becomes diffraction-limited at a wider aperture than a 12 MP model, making this calculation critical for high-resolution landscape work.
• Product Photography: Find the sharpest aperture when focus stacking is not an option. Ensure that small apertures used for depth of field do not sacrifice the fine detail needed for e-commerce product images.
• Macro Photography: Evaluate diffraction effects when shooting at very small apertures such as f/22 or f/32, which are commonly needed for sufficient depth of field at close focusing distances.
• Astrophotography: Adjust the light wavelength setting to evaluate diffraction for narrowband filters (such as H-alpha at 656 nm) and confirm whether aperture choice maintains resolving power at non-visible wavelengths.
• Camera Comparison: Compare different camera bodies to understand how pixel density affects the diffraction-limited aperture. Higher megapixel sensors have smaller pixels and become diffraction-limited sooner.
• Education: Visualize the relationship between aperture, wavelength, and pixel pitch through the step-by-step formula derivation. Diffraction is a fundamental optical limit, not a lens defect.
• Video Production: Assess whether stopping down for consistent exposure across a scene will degrade resolving power on 4K or 8K sensors where pixel pitch is small.