Diffraction Calculator for Infrared, Visible Light, and UV
Pick your camera and filter to find the sharpest aperture: the table compares the Airy disk at each ƒ-stop and wavelength, from ultraviolet through visible light to infrared, with your sensor’s pixel pitch.
| No visible diffraction (less than 3) | |
| Visible diffraction may slightly impact image sharpness (3 to 4.5) | |
| Visible diffraction will impact image sharpness (4.5 or greater) |
How To Use
- Camera select a camera. If your camera is not listed, request to add it here.
- Filter select a filter. If a column is gray, that wavelength of light will not be transmitted by the selected filter. See which wavelengths each filter passes.
- Select
Full spectrumwhen using a full spectrum converted camera with no additional filter. If you use a full spectrum camera with an additional filter, then select the filter used. - Select
Hot mirror or UV/IR cutfor an unconverted camera, as these contain a hot mirror filter, or when using a full spectrum camera with an added UV/IR cut filter. - If you add a filter to an unconverted camera, select that filter. This should be a 720 nm or higher filter.
- Select
- ƒ-stops switch between (whole) and (third) values.
- Safe shows the highest ƒ-number that you can use to completely avoid diffraction. This ƒ-number has a Diffraction ratio of 3 or lower at all wavelengths.
- Caution shows the ƒ-number that you can use with mild visible diffraction. This ƒ-number has a Diffraction ratio of 3.75 or lower at all wavelengths.
- Avoid shows the ƒ-number that will produce visible diffraction. This ƒ-number has a Diffraction ratio of 4.5 or higher at some wavelengths.
- Safe, Caution, and Avoid ƒ-stops are calculated to the one-third ƒ-stop regardless of whether you are viewing the whole stop or one-third ƒ-stop table.
- Optionally, select the row of the ƒ-stop you wish to shoot at.