Sony α7 IV Diffraction Limit
With a 720 nm infrared filter, the Sony α7 IV stays free of visible diffraction up to ƒ/6.3, and diffraction starts to soften images at ƒ/10.1. Unconverted (hot mirror), it is diffraction-free up to ƒ/8 and soft from ƒ/14.3. These limits come from its 5.12 μm pixel pitch: longer infrared wavelengths make a larger Airy disk, so diffraction appears at wider apertures than in visible light.
Open the Sony α7 IV in the calculator
Sony α7 IV specifications
- Pixel pitch: 5.12 μm
- Megapixels: 33.0
- Pixels: 7008 × 4672
- Sensor: Full Frame, 35.9 × 23.9 mm
Buy the Sony α7 IV: 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/6.3 | ƒ/7.1 | ƒ/10.1 |
| Hot mirror or UV/IR cut | ƒ/8 | ƒ/10.1 | ƒ/14.3 |
| 470 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 550 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 590 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 665 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 720 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 780 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 830 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 930 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| 1000 nm high-pass | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| IR Chrome | ƒ/6.3 | ƒ/7.1 | ƒ/10.1 |
| UV Bandpass | ƒ/14.3 | ƒ/18 | ƒ/25.4 |
Diffraction ratio at each ƒ-stop
The Airy disk diameter divided by the 5.12 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 | 0.23 | 0.27 | 0.31 | 0.37 | 0.39 | 0.44 | 0.48 | 0.52 | 0.55 | 0.62 | 0.67 |
| ƒ/2 | 0.33 | 0.38 | 0.45 | 0.52 | 0.56 | 0.63 | 0.69 | 0.74 | 0.79 | 0.89 | 0.95 |
| ƒ/2.8 | 0.47 | 0.53 | 0.63 | 0.73 | 0.79 | 0.89 | 0.96 | 1.04 | 1.11 | 1.24 | 1.33 |
| ƒ/4 | 0.67 | 0.76 | 0.9 | 1.05 | 1.12 | 1.27 | 1.37 | 1.49 | 1.58 | 1.77 | 1.91 |
| ƒ/5.6 | 0.93 | 1.07 | 1.25 | 1.47 | 1.57 | 1.77 | 1.92 | 2.08 | 2.22 | 2.48 | 2.67 |
| ƒ/8 | 1.33 | 1.53 | 1.79 | 2.1 | 2.25 | 2.54 | 2.75 | 2.97 | 3.16 | 3.55 | 3.81 |
| ƒ/11 | 1.83 | 2.1 | 2.46 | 2.88 | 3.09 | 3.49 | 3.77 | 4.09 | 4.35 | 4.88 | 5.24 |
| ƒ/16 | 2.67 | 3.05 | 3.58 | 4.19 | 4.5 | 5.07 | 5.49 | 5.95 | 6.33 | 7.09 | 7.63 |
| ƒ/22 | 3.67 | 4.19 | 4.93 | 5.77 | 6.19 | 6.97 | 7.55 | 8.18 | 8.7 | 9.75 | 10.48 |
| ƒ/32 | 5.34 | 6.1 | 7.17 | 8.39 | 9 | 10.14 | 10.98 | 11.9 | 12.66 | 14.18 | 15.25 |
| 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 Full Frame cameras within 0.2 μm of the Sony α7 IV. The same pixel pitch gives the same diffraction limits.
- Sony α7 V (5.12 μm)
- Sony α7C II (5.12 μm)
- Canon EOS R6 Mark III (5.16 μm)
Pixel pitch comes from the camera database. Send a correction if anything here is wrong.