Depth of Field Calculator

What it does

Calculates the near and far limits of acceptably sharp focus around your focus distance, using the hyperfocal-distance method — the standard approach for depth of field, based on your lens's focal length and aperture plus your sensor's circle of confusion (how large a blur spot still reads as “sharp” at normal viewing size).

What you'll need

• Focal length in mm — the actual lens focal length, not a 35mm-equivalent.
• Aperture (f-number) you're shooting at.
• Focus distance — how far the point you're focusing on is from the camera.
• Sensor format — sets the circle of confusion used in the calculation.

Steps

1. Enter your focal length, aperture and focus distance.
2. Pick your camera's sensor format.
3. Read the near/far limits and total depth of field.

Reading the result

Near and far limits are the closest and furthest points that will still look acceptably sharp. If far limit shows infinity, everything from the near limit outward is in focus — this happens once your focus distance passes the hyperfocal distance shown at the bottom.

Tips

• For landscapes, focusing near (not at) the hyperfocal distance typically maximises sharp foreground-to-background coverage — see the Hyperfocal Distance Guide tool for that specifically.
• Circle of confusion is a convention, not a hard physical line — depth of field falls off gradually, not at a sharp cutoff.

What is depth of field?

Depth of field is the zone in front of and behind your focus point that still reads as acceptably sharp. It isn't a hard edge — sharpness fades gradually the further you move from the focus point — so every depth-of-field calculation, including this one, is built on a convention (the circle of confusion) for how much blur still counts as “sharp” at normal viewing size.

Why photographers use it

Depth of field is how you decide how much of a scene stays in focus, and that decision changes the whole feel of a shot. A thin sliver of sharpness isolates a subject from a busy background — the look most portraits and product close-ups want. A deep zone of sharpness, front to back, is what a landscape needs when both a foreground rock and a distant mountain have to read clearly in the same frame.

Which depth of field should I aim for?

For subject isolation (portraits, headshots, product shots), go wide aperture, get physically closer to your subject, and use a longer focal length if you can — all three shrink depth of field. For landscapes and anything that needs front-to-back sharpness, do the opposite: narrow the aperture, keep more distance between you and the nearest element, and consider focusing near the hyperfocal distance instead of on your main subject (see the Hyperfocal Distance Guide tool for that specifically). For group shots or product flat-lays, aim for a moderate aperture (f/5.6-f/8 on full-frame) that gives enough coverage without needing an extreme setting.

Common mistakes

• Assuming aperture alone controls depth of field. focus distance and focal length matter just as much. f/1.8 on a landscape 50 metres away still renders enormous depth of field, because distance dominates the calculation at that range — a wide aperture close up behaves completely differently from the same aperture far away.
• Mistaking the near limit for the focus point. the near limit is always closer to the camera than where you actually focused — it's the front edge of the sharp zone, not the point itself. The focus point sits inside the sharp range, not at its boundary.
• Stopping down further and further expecting more sharpness. past a lens's optimal aperture (often f/8-f/11 on full-frame), diffraction starts softening the entire image, working against the extra depth of field you're gaining. f/22 isn't automatically better than f/11 for overall image quality.
• Ignoring sensor format when comparing results. the same focal length and aperture give meaningfully different depth of field on a full-frame body versus an APS-C or Micro Four Thirds body, because of both the circle of confusion convention and the different angle of view at that focal length.
• Reaching for the aperture ring first. when subject distance is the biggest lever of all — stepping closer to your subject shrinks depth of field far more dramatically than tightening the aperture by a stop or two.

Example settings

FAQ

What's the difference between near limit, far limit and total DoF?

Near and far limit are the closest and furthest points from the camera that still look acceptably sharp. Total DoF is simply the distance between them — the size of the whole sharp zone.

Why did the far limit show infinity?

Your focus distance passed the hyperfocal distance for that focal length and aperture — once that happens, everything from the near limit outward to the horizon is sharp, so there's no finite far edge.

Does sensor size actually change depth of field, or just the framing?

Both. A smaller sensor uses a tighter circle-of-confusion convention (since the image gets magnified more to reach the same output size), which pulls in the sharp zone even before you account for how crop factor changes your effective field of view.

What exactly is "circle of confusion" and why does the calculator need it?

It's the largest a single point of light is allowed to blur into before a viewer's eye stops perceiving it as a sharp point, at normal viewing size. It's a practical convention, not a hard physical constant — this calculator uses standard values per sensor format.

Why do two lenses at the same aperture and distance give different depth of field?

Focal length itself is part of the hyperfocal distance formula — longer lenses compress depth of field for a given subject distance, which is part of why telephoto portraits blur backgrounds more easily than wide-angle ones at the same aperture.