Depth of field calculator
Pick a camera, its recording mode, a lens, a stop and a focus distance. You get the near and far limits of focus, the total depth and the hyperfocal distance, with the circle of confusion the Viewfinder app would use for that gate.
With JavaScript off this shows an ARRI ALEXA 35 in 4.6K 16:9 on a 35mm at T2.8, focused at 3 m. Turn it on to pick any camera, lens, stop and distance.
In front of focus 43 cm, behind 61 cm · circle of confusion 0.025 mm, nearest to Super 35
| Stop | Near | Far | Total | Hyperfocal |
|---|---|---|---|---|
| T1.4 | 2.77 m | 3.28 m | 51 cm | 35.0 m |
| T2 | 2.68 m | 3.41 m | 74 cm | 24.5 m |
| T2.8 | 2.57 m | 3.61 m | 1.05 m | 17.5 m |
| T4 | 2.42 m | 3.96 m | 1.54 m | 12.3 m |
| T5.6 | 2.24 m | 4.54 m | 2.30 m | 8.79 m |
| T8 | 2.02 m | 5.81 m | 3.79 m | 6.16 m |
| T11 | 1.80 m | 8.97 m | 7.17 m | 4.49 m |
| T16 | 1.52 m | 94.2 m | 92.7 m | 3.10 m |
On this page
What the four numbers mean
Near and far are the closest and farthest distances that still look sharp when you focus at the distance you typed. Total is the depth between them. Hyperfocal is the focus distance where everything from half of it to infinity looks sharp: focus there and the far limit runs out to the horizon.
Sharp enough is an agreement, set by the circle of confusion: the size of blur, on the sensor, that a viewer still reads as a point. A smaller value is stricter and gives shallower depth. That is why the same lens and stop give different depth on Super 16 and on full frame.
How the circle of confusion is chosen
Leave it on From the recording mode and the calculator does what Cutvey Viewfinder does: it measures the diagonal of the mode you picked and takes the nearest of four film formats, or a fixed fraction for very small sensors.
| Gate | Reference size | Circle of confusion |
|---|---|---|
| Super 16 (and Micro Four Thirds) | 12.52 × 7.41 mm | 0.015 mm |
| Super 35 | 24.89 × 18.66 mm | 0.025 mm |
| Full frame and large format | 36 × 24 mm | 0.030 mm |
| 65mm | 52.63 × 23.01 mm | 0.042 mm |
| Any gate under 11 mm across the diagonal | diagonal ÷ 1500 |
Pick a format yourself, or type your own value, if your production uses a stricter standard for a big screen.
A worked example
An ARRI ALEXA 35 in 4.6K 16:9 is 27.99 × 15.75 mm, a diagonal of 32.1 mm, so it takes the Super 35 value of 0.025 mm. On a 35mm at T2.8 focused at 3 m, sharpness runs from 2.57 m to 3.61 m, about 1.05 m deep, and the hyperfocal distance is 17.5 m.
Two more, worked the same way:
- An 85mm at T2 on full frame (0.030 mm), focused at 2.5 m for a close single: 2.45 m to 2.55 m, only 10 cm. That is a focus puller's day.
- A 24mm at T5.6 on Super 35, focused at 3 m for a wide exterior: 1.74 m to 10.8 m. Focus at the hyperfocal distance, 4.14 m, and everything from 2.07 m to infinity holds.
Where these numbers stop being exact
The math is the exact thin-lens form, with distances measured from the lens's front principal plane, which sits a little in front of the film plane mark on the camera. Three things it does not model, the same as the app:
- The stop. The marked T-stop stands in for the f-number. A T-stop is a little slower than the f-number of the same lens, so the depth shown runs roughly 5 to 15 percent deeper than the optics give.
- Anamorphic squeeze. The figures are for the taking lens's focal length and stop; the squeeze is not applied.
- Focus breathing. The focal length is the marked one at every distance.
Treat the near and far as planning marks, then confirm on the monitor.
The same panel in the app
In Cutvey Viewfinder the depth of field panel sits on the viewfinder, reads the camera, mode and lens you are framing, and can draw the in-focus band. Read depth of field in the app, or see how it works.
Questions
Why does my depth of field differ from another calculator?
Most calculators use one circle of confusion for every camera, often 0.030 mm, and the approximate formulas. This one picks the value from the recording mode's gate and uses the exact thin-lens form, which matters at close focus.
Should I type the T-stop or the f-stop?
Type what you will set on the lens. The app and this page use the marked T-stop as the f-number, which shows slightly more depth than the true f-number would.
Does it work in feet?
Yes. Switch the distances to feet and type the focus distance in feet; near, far and hyperfocal follow.
Is anything I type sent anywhere?
No. The calculator runs in your browser, reads only this site's gear list, and stores nothing. The address bar holds your settings so you can copy the link.
Related
See the frame before the camera arrives
Cutvey Viewfinder frames any camera, recording mode and lens on your iPhone or iPad. $19.99, once.