Depth of field (DoF) controls how much of your shot is sharp. For portrait shooters chasing creamy bokeh: maximize aperture (low f-number), get close, use a long lens. For landscape shooters chasing edge-to-edge sharpness: stop down, focus at the hyperfocal distance. This calculator runs the actual DoF math for your specific camera (sensor format), lens (focal length), aperture, and focus distance. Outputs near focus limit, far focus limit, total DoF, and hyperfocal distance. Real numbers, not depth-of-field marketing fluff.
Focal length: longer lens = shallower DoF at the same f-number and distance. A 200mm at f/2.8 has dramatically less DoF than a 50mm at f/2.8.
Focus distance: closer to the subject = shallower DoF. Macro work has razor-thin DoF even at small apertures.
Sensor size matters indirectly: smaller sensors (M4/3, APS-C) have deeper DoF than full frame at the same focal length and f-stop because of the smaller circle of confusion. Or framed differently: to get the same FOV from a closer M4/3 sensor, you'd need to use a 25mm at f/2.8 instead of full-frame 50mm at f/5.6 — same DoF at equivalent setting.
Worked examples
Portrait: 85mm f/1.4 at 8 ft on full frame. Near focus 7.83 ft, far focus 8.17 ft. Total DoF: 0.34 ft (4 inches). Razor thin — nose tip will be out of focus if focus is on eyes.
Landscape: 24mm f/11 on full frame, focused at hyperfocal distance. Hyperfocal = 17.5 ft. Everything from 8.75 ft to infinity is acceptably sharp. Foreground rocks and distant mountains both in focus.
Street: 35mm f/8 at 15 ft on full frame. Near focus 8 ft, far focus 100+ ft (toward infinity). Anything 8-100 ft is sharp — zone-focus territory for fast street shooting.
How to use this calculator
Sensor / Format: pick your camera type — different sensor sizes have different circles of confusion.
Focal length: in mm, of the actual lens (not 35mm equivalent).
Aperture: f-stop you're shooting at.
Focus distance: in feet from camera to subject.
Output: total DoF, near focus, far focus, and hyperfocal distance for the lens.
FAQ
What's hyperfocal distance? +
The closest focus distance at which infinity is still acceptably sharp. Focus the lens there and everything from half that distance to infinity is in focus. The maximum-DoF trick landscape photographers use.
Why does the circle of confusion (CoC) matter? +
CoC is the smallest blur circle that still looks sharp at typical viewing distance and print size. Different sensor sizes need different CoC values for consistent perceived sharpness. The calculator's presets use standard values (FF 0.030 mm, APS-C 0.019, MFT 0.015). Pixel-peeping on a screen makes the effective CoC smaller — use a tighter value if you regularly view at 100%.
How accurate is this for digital sensors? +
Very for moderate-to-deep DoF. At very shallow DoF (f/1.4 close-up), diffraction and lens aberrations matter as much as the geometric DoF math. Use these numbers as a planning starting point; check actual focus with the camera.
Why do crop sensors look like they have deeper DoF? +
Because to frame the same shot with a crop sensor, you use a shorter lens (35mm on APS-C ≈ 50mm equivalent FOV on FF). A shorter lens at the same f-stop has deeper DoF. So at equivalent framings, crop sensors deliver more DoF.
What's diffraction-limited aperture? +
The aperture where lens diffraction reduces sharpness more than smaller aperture improves DoF. On full frame: f/16 starts showing diffraction; f/22 noticeably softens. On crop: diffraction kicks in at f/11. On smartphones / M4/3: f/8 is the practical floor. Don't stop down past these unless you absolutely need the DoF.
How do I focus at hyperfocal distance practically? +
Two ways: (1) use the lens's distance scale (most prime lenses have one) and set the appropriate aperture's far DoF mark to infinity. (2) Take a test shot and confirm via live view zoom. Manual focus prime lenses make this easy; modern AF zooms often skip distance scales and require workarounds.
Does focal length affect DoF or just background blur? +
Both — but the relationship is subtle. At equal framing (same subject size in frame), focal length matters less. At equal distance (camera-to-subject), longer focal length = shallower DoF. The "compression" effect of long lenses isn't just framing — it includes the dramatically shallower DoF and shifted background-to-subject distance.
What about focus stacking? +
For situations where you need MORE depth than even small apertures provide (macro, product photography), focus stacking captures multiple shots at different focus distances and combines them in post. Common in macro work with focus stacking software (Helicon Focus, Photoshop). Bypasses the diffraction limit entirely.