f/4.5
Aperture
4.3
Stops less light than f/1
4.94%
Light vs f/1
98.1 cm
DoF: 50 mm at 3 m (FF)
6.0 µm
Airy disk diameter
Depth of field at f/4.5 (full frame)#
| Focal | at 1 m | at 2 m | at 5 m | at 10 m | Hyperfocal |
|---|---|---|---|---|---|
| 16 mm | 1.42 m | ∞ | ∞ | ∞ | 1.91 m |
| 24 mm | 48.3 cm | 2.36 m | ∞ | ∞ | 4.29 m |
| 35 mm | 21.5 cm | 90.9 cm | 7.81 m | ∞ | 9.11 m |
| 50 mm | 10.3 cm | 42.6 cm | 2.88 m | 15.1 m | 18.6 m |
| 85 mm | 3.4 cm | 14.3 cm | 92.6 cm | 3.84 m | 53.6 m |
| 135 mm | 1.3 cm | 5.5 cm | 36.1 cm | 1.47 m | 135 m |
| 200 mm | 0.5 cm | 2.4 cm | 16.2 cm | 66.2 cm | 296 m |
Diffraction at f/4.5#
Diffraction softening becomes visible at 100% once the Airy disk spans more than about two pixels. It is a gradual effect, not a cliff.
| Sensor | Pixel pitch | Airy disk / pixel | Pixel-level sharpness |
|---|---|---|---|
| Full frame 24 MP | 6.00 µm | 1.0× | no visible loss |
| Full frame 45 MP | 4.39 µm | 1.4× | no visible loss |
| Full frame 61 MP | 3.79 µm | 1.6× | no visible loss |
| APS-C 24 MP | 3.92 µm | 1.5× | no visible loss |
| APS-C 40 MP | 3.04 µm | 2.0× | no visible loss |
| Micro Four Thirds 20 MP | 3.34 µm | 1.8× | no visible loss |
| 1-inch 20 MP | 2.41 µm | 2.5× | slight softening |
| Smartphone 1/1.3" 50 MP | 1.17 µm | 5.2× | diffraction-limited |
f/4.5 on smaller sensors equals…#
Exposure (brightness) is the same at a given f-number on every format; equivalence describes depth of field and total light.
| Used on | Full-frame equivalent depth of field |
|---|---|
| APS-C (1.5×) | f/6.8 |
| Canon APS-C (1.6×) | f/7.2 |
| Micro Four Thirds (2×) | f/9.0 |
| 1-inch (2.7×) | f/12.2 |
Shutter speed at f/4.5#
| Light | ISO 100 | ISO 400 | ISO 1600 | ISO 6400 |
|---|---|---|---|---|
| EV 15 · Bright sun, distinct shadows (Sunny 16) | 1/1600 s | 1/6400 s | too bright | too bright |
| EV 13 · Cloudy-bright, no shadows | 1/400 s | 1/1600 s | 1/6400 s | too bright |
| EV 12 · Heavy overcast / open shade | 1/200 s | 1/800 s | 1/3200 s | too bright |
| EV 10 · Just after sunset | 1/50 s | 1/200 s | 1/800 s | 1/3200 s |
| EV 8 · Bright interior, city street at night | 1/13 s | 1/50 s | 1/200 s | 1/800 s |
| EV 5 · Home interior at night | 0.6 s | 1/6 s | 1/25 s | 1/100 s |
| EV 2 · Distant city lights | 5 s | 1.3 s | 0.3 s | 1/13 s |
| EV -2 · Moonlit landscape | 1 min | 20 s | 5 s | 1.3 s |
When to use f/4.5#
f/4.5 is a go-to setting for the sharpest zone of most lenses — groups, travel, street ("f/8 and be there") and landscapes on smaller sensors.
Other apertures#
Frequently asked questions#
Is f/4.5 a wide aperture?
It is a medium aperture. Smaller numbers mean larger openings.
How much light does f/4.5 let in compared to f/2.8?
0.39× (-1.4 stops).
Last updated October 03, 2026 · How we calculate · Sources