Fujifilm X-T1 Diffraction Limit
With a 720 nm infrared filter, the Fujifilm X-T1 stays free of visible diffraction up to ƒ/5.6, and diffraction starts to soften images at ƒ/9. Unconverted (hot mirror), it is diffraction-free up to ƒ/8 and soft from ƒ/12.7. These limits come from its 4.82 μm pixel pitch: longer infrared wavelengths make a larger Airy disk, so diffraction appears at wider apertures than in visible light.
Open the Fujifilm X-T1 in the calculator
Fujifilm X-T1 specifications
- Pixel pitch: 4.82 μm
- Megapixels: 16.3
- Pixels: 4896 × 3264
- Sensor: APS-C, 23.6 × 15.6 mm
Buy the Fujifilm X-T1: KEH Adorama B&H
Sharpest ƒ-stop by filter
Safe is the narrowest aperture with a diffraction ratio of 3 or lower at every wavelength the filter passes. Caution allows up to 3.75. Avoid is the first aperture where any wavelength reaches 4.5. All three are calculated to the one-third stop. See which wavelengths each filter passes.
| Filter | Safe | Caution | Avoid |
|---|---|---|---|
| Full spectrum | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| Hot mirror or UV/IR cut | ƒ/8 | ƒ/10.1 | ƒ/12.7 |
| 470 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 550 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 590 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 665 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 720 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 780 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 830 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 930 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| 1000 nm high-pass | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| IR Chrome | ƒ/5.6 | ƒ/7.1 | ƒ/9 |
| UV Bandpass | ƒ/14.3 | ƒ/18 | ƒ/25.4 |
Diffraction ratio at each ƒ-stop
The Airy disk diameter divided by the 4.82 μm pixel pitch, for every wavelength from ultraviolet to infrared. A filter only passes some of these wavelengths; the table above applies each filter’s set. How the ratio is calculated.
| ƒ-stop | 350 nm | 400 nm | 470 nm | 550 nm | 590 nm | 665 nm | 720 nm | 780 nm | 830 nm | 930 nm | 1000 nm |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ƒ/1.4 | 0.25 | 0.28 | 0.33 | 0.39 | 0.42 | 0.47 | 0.51 | 0.55 | 0.59 | 0.66 | 0.71 |
| ƒ/2 | 0.35 | 0.4 | 0.48 | 0.56 | 0.6 | 0.67 | 0.73 | 0.79 | 0.84 | 0.94 | 1.01 |
| ƒ/2.8 | 0.5 | 0.57 | 0.67 | 0.78 | 0.84 | 0.94 | 1.02 | 1.11 | 1.18 | 1.32 | 1.42 |
| ƒ/4 | 0.71 | 0.81 | 0.95 | 1.11 | 1.19 | 1.35 | 1.46 | 1.58 | 1.68 | 1.88 | 2.02 |
| ƒ/5.6 | 0.99 | 1.13 | 1.33 | 1.56 | 1.67 | 1.89 | 2.04 | 2.21 | 2.35 | 2.64 | 2.83 |
| ƒ/8 | 1.42 | 1.62 | 1.9 | 2.23 | 2.39 | 2.69 | 2.92 | 3.16 | 3.36 | 3.77 | 4.05 |
| ƒ/11 | 1.95 | 2.23 | 2.62 | 3.06 | 3.29 | 3.7 | 4.01 | 4.34 | 4.62 | 5.18 | 5.57 |
| ƒ/16 | 2.83 | 3.24 | 3.81 | 4.45 | 4.78 | 5.39 | 5.83 | 6.32 | 6.72 | 7.53 | 8.1 |
| ƒ/22 | 3.9 | 4.45 | 5.23 | 6.13 | 6.57 | 7.41 | 8.02 | 8.69 | 9.24 | 10.36 | 11.14 |
| ƒ/32 | 5.67 | 6.48 | 7.61 | 8.91 | 9.56 | 10.77 | 11.66 | 12.64 | 13.45 | 15.07 | 16.2 |
| 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) |
Cameras with similar pixel pitch
Other APS-C cameras within 0.2 μm of the Fujifilm X-T1. The same pixel pitch gives the same diffraction limits.
- Fujifilm X-A1 (4.82 μm)
- Fujifilm X-A10 (4.82 μm)
- Fujifilm X-A2 (4.82 μm)
- Fujifilm X-A20 (4.82 μm)
- Fujifilm X-E1 (4.82 μm)
- Fujifilm X-E2 (4.82 μm)
Pixel pitch comes from the camera database. Send a correction if anything here is wrong.