How to use it
- Choose the sensor — full frame, Super 35 or 2/3″ broadcast (B4) — and feet or metres.
- Turn the focal length, aperture and focus distance dials. Drag them, or on a computer scroll over a dial, or click it and use the arrow keys. For an exact focal length or distance — 73mm, 237 ft, 12′6″, 72.5 m — tap the number beside the dial and type it.
- Read the near and far limits. The picture shows how soft the background falls at that setting, in five real locations or on a concert stage.
- The badge on the picture names the shot — wide, medium, close-up and so on — and gives the frame’s width and height at the subject: how tight that lens gets from that distance.
- Switch to 2 People and stagger the second person to see who drops out of focus.
What the numbers mean
- Near limit
- The closest point that is still acceptably sharp.
- Far limit
- The farthest point that is still acceptably sharp. ∞ means everything beyond the focus point is sharp.
- Total depth
- The far limit minus the near limit — how deep the sharp zone is.
- Hyperfocal distance
- Focus here and everything from half this distance to infinity is acceptably sharp.
How it’s calculated
Near = s (H − f) ÷ (H + s − 2f)
Far = s (H − f) ÷ (H − s) — ∞ once s reaches H
f is the focal length, N the f-number, s the focus distance and c the circle of confusion: the sensor’s diagonal ÷ 1500 — 0.029 mm on full frame, 0.019 mm on Super 35 and 0.0073 mm on 2/3″ (the 9.59 × 5.39 mm 16:9 frame). The picture is a real photograph for each location, blurred band by band: near ground, middle distance and far background each defocus by their own distance from the focus plane, the way a lens does it. The stage is drawn at true size instead — LED wall, truss and audience at real distances from the performer — so it stays sharp on a 2000mm broadcast zoom.
Hyperfocal distance — full frame
| Lens | f/2 | f/2.8 | f/4 | f/5.6 | f/8 | f/11 |
|---|---|---|---|---|---|---|
| 18mm | 18' 6" 5.6 m | 13' 3" 4.0 m | 9' 3" 2.8 m | 6' 8" 2.0 m | 4' 8" 1.4 m | 3' 5" 1.0 m |
| 24mm | 32' 10" 10.0 m | 23' 6" 7.2 m | 16' 5" 5.0 m | 11' 9" 3.6 m | 8' 3" 2.5 m | 6' 0" 1.8 m |
| 35mm | 69' 9" 21.3 m | 49' 11" 15.2 m | 34' 11" 10.7 m | 25' 0" 7.6 m | 17' 6" 5.3 m | 12' 9" 3.9 m |
| 50mm | 142' 4" 43.4 m | 101' 9" 31.0 m | 71' 3" 21.7 m | 50' 11" 15.5 m | 35' 9" 10.9 m | 26' 0" 7.9 m |
| 85mm | 411' 2" 125.3 m | 293' 9" 89.5 m | 205' 9" 62.7 m | 147' 0" 44.8 m | 103' 0" 31.4 m | 75' 0" 22.9 m |
Hyperfocal distance — Super 35
| Lens | f/2 | f/2.8 | f/4 | f/5.6 | f/8 | f/11 |
|---|---|---|---|---|---|---|
| 18mm | 28' 0" 8.5 m | 20' 0" 6.1 m | 14' 0" 4.3 m | 10' 0" 3.1 m | 7' 0" 2.1 m | 5' 2" 1.6 m |
| 24mm | 49' 8" 15.1 m | 35' 6" 10.8 m | 24' 11" 7.6 m | 17' 10" 5.4 m | 12' 6" 3.8 m | 9' 1" 2.8 m |
| 35mm | 105' 8" 32.2 m | 75' 6" 23.0 m | 52' 10" 16.1 m | 37' 10" 11.5 m | 26' 6" 8.1 m | 19' 4" 5.9 m |
| 50mm | 215' 6" 65.7 m | 154' 0" 46.9 m | 107' 10" 32.9 m | 77' 1" 23.5 m | 54' 0" 16.5 m | 39' 4" 12.0 m |
| 85mm | 622' 8" 189.8 m | 444' 10" 135.6 m | 311' 5" 94.9 m | 222' 7" 67.8 m | 155' 10" 47.5 m | 113' 5" 34.6 m |
Hyperfocal distance — 2/3″ broadcast
| Lens | f/2 | f/2.8 | f/4 | f/5.6 | f/8 | f/11 |
|---|---|---|---|---|---|---|
| 4.3mm | 4' 2" 1.3 m | 3' 0" 0.9 m | 2' 1" 0.6 m | 1' 6" 0.5 m | 1' 1" 0.3 m | 0' 9" 0.2 m |
| 8.2mm | 15' 1" 4.6 m | 10' 9" 3.3 m | 7' 7" 2.3 m | 5' 5" 1.6 m | 3' 9" 1.2 m | 2' 9" 0.8 m |
| 14mm | 43' 11" 13.4 m | 31' 4" 9.6 m | 22' 0" 6.7 m | 15' 8" 4.8 m | 11' 0" 3.4 m | 8' 0" 2.4 m |
| 25mm | 139' 11" 42.6 m | 99' 11" 30.5 m | 70' 0" 21.3 m | 50' 0" 15.2 m | 35' 0" 10.7 m | 25' 6" 7.8 m |
| 50mm | 559' 4" 170.5 m | 399' 7" 121.8 m | 279' 9" 85.3 m | 199' 10" 60.9 m | 140' 0" 42.7 m | 101' 10" 31.0 m |
Questions
What circle of confusion does this use?
The sensor’s diagonal divided by 1500: 0.029 mm for full frame, 0.019 mm for Super 35 and 0.0073 mm for 2/3″. It’s a common convention for film and photo planning.
How tight can I get on someone from the back of the venue?
Pick the sensor, the lens and the distance: the badge on the picture names the shot of a 5′ 9″ person and gives the frame’s width and height at that distance. A Canon UJ122x8.2B with its 2× extender in reaches 2000mm on a 2/3″ camera; at 300 ft that frame is about 10 inches tall — a close-up. A Fujinon Duvo 25-1000 with its 1.5× in reaches 1500mm on full frame.
Does the sensor size change depth of field?
Yes. With the same lens, stop and distance, Super 35 gives a slightly shallower sharp zone than full frame, because its circle of confusion is smaller. Framed the same way — a wider lens or a longer distance — the smaller sensor gives more depth of field.
My cine lens is marked in T-stops. Which do I use?
Depth of field follows the f-stop, the lens’s geometric aperture. A T-stop measures light and is a little slower than the f-stop, so using the T-stop gives a close, slightly generous answer — fine for planning.
Can I use it on set without signal?
Yes — in the free CamPlot Calculators app for iPhone, where every calculation runs on the phone.