Sharpest Aperture for Every Camera
Every lens has a sweet spot. Diffraction-limited apertures computed for real cameras: where the Airy disk meets your sensor's pixel pitch — and the practical f-stops to use.
Every lens has a sharpness sweet spot. Wide open, optical aberrations soften the edges; stop down and they improve — but eventually diffraction takes over and the image softens again. The balance point is different for every camera, and it's computable.
The Airy disk: where softness comes from
Light passing through a circular aperture doesn't focus to a point — it spreads into a blur disc called the Airy disk, diameter 2.44 × λ × N (λ ≈ 0.55 µm for green light). When that disk grows larger than your sensor's pixels, diffraction is visible at 100%:
| Aperture | Airy disk diameter |
|---|---|
| f/1.4 | 1.9 µm |
| f/2 | 2.7 µm |
| f/2.8 | 3.8 µm |
| f/4 | 5.4 µm |
| f/5.6 | 7.5 µm |
| f/8 | 10.7 µm |
| f/11 | 14.8 µm |
| f/16 | 21.5 µm |
| f/22 | 29.5 µm |
Diffraction-limited aperture for real cameras
Pixels are smaller on high-resolution sensors, so they hit the diffraction wall sooner. The table shows each camera's pixel pitch and the f-stop where the Airy disk reaches about two pixels — the practical point of visible softening:
| Camera | Sensor | Pixel pitch | Diffraction-limited ≈ |
|---|---|---|---|
| Sony A1 II | 36.0 × 24.0 mm | 4.17 µm | ≈ f/8 |
| Sony A7 IV | 36.0 × 24.0 mm | 5.14 µm | ≈ f/8 |
| Canon EOS R5 II | 36.0 × 24.0 mm | 4.39 µm | ≈ f/8 |
| Fujifilm X-T5 | 23.5 × 15.6 mm | 3.03 µm | ≈ f/5.6 |
| OM System OM-1 II | 17.4 × 13.0 mm | 3.35 µm | ≈ f/5.6 |
| iPhone 16 Pro | 9.8 × 7.3 mm | 1.21 µm | ≈ f/2 |
Practical sweet spots
- Portraits: f/1.8–f/2.8 — sharpness isn't the point; blur is.
- Landscapes (tripod): f/8–f/11 — f/8 is the safe sweet spot, f/11 for extra DoF.
- Real estate / interiors: f/8 — enough depth, still pixel-sharp.
- Macro: stop down freely; focus stacking beats diffraction.
Want the numbers for your exact camera and lens? The free depth of field calculator pairs any body in the database with any aperture.
Related tools & guides
Depth of Field Calculator
DoF and hyperfocal for your exact sensor.
Open →Camera Sensor Sizes
Why pixel pitch and format matter.
Read →DoF for Landscape
Hyperfocal, stacking and the f-stop sweet spot.
Read →Diffraction FAQ
What is the sharpest aperture?
Usually f/4–f/8 on full frame. Past f/8–f/11 diffraction starts softening detail at the pixel level.
Is f/16 unusable?
No. At print sizes the softening is invisible; f/16 is fine when you need maximum depth of field and can't stack.
Do phone cameras diffract?
Yes, and much earlier — a 48 MP phone sensor is diffraction-limited around f/1.8–f/2. That's why phone lenses stay wide open.