How do I recalibrate my ZED stereo camera?

All ZED cameras (ZED X, ZED X Mini, ZED X Nano, ZED 2i, ZED Mini, and the monocular ZED X One) undergo an extensive and rigorous multi-step factory calibration process using special equipment that guarantees highly accurate stereo and sensor calibration.

Note: The original ZED and the ZED 2 are out of production and may no longer be supported by newer versions of the ZED SDK.

The factory calibration is typically more accurate than user calibrations; however, you may want to recalibrate your camera in the following situations:

  • If you have a ZED camera rev.1 (produced before 2020). In 2020, we updated the ZED stereo camera internals to a new revision (rev.2) which dramatically improves stereo calibration consistency over time.
  • If your camera has suffered a hard impact, or exposure to extreme temperatures, that may have caused internal parts to shift slightly.
  • If you have enclosed your camera in an external or underwater case, or placed glass in front of the lenses.

For more information about how the ZED's calibration works, see the What is the calibration file? article and the Camera Calibration documentation.

Do I really need to recalibrate?

In many cases, no. By default, the ZED SDK runs a self-calibration process every time a stereo camera is opened. This step refines the factory calibration on the fly, correcting the small offsets that develop over time or with changing operating conditions (mechanical stress, vibrations, or thermal expansion of the camera body). The optimized parameters are then automatically used for rectification and depth estimation.

You can also trigger self-calibration manually at any time after the camera is opened by calling Camera::updateSelfCalibration(); this is useful, for example, to compensate for temperature drift after the camera warms up.

Self-calibration handles small deviations, but it cannot compensate for major optical changes such as an underwater housing, protective glass, or physical damage. In those cases, a full recalibration is required.

Camera Calibration File

Your camera calibration is stored in a file named after the camera's serial number (e.g. SNxxxxxxx.conf), located in the following folders:

  • On Windows: C:\ProgramData\StereoLabs\settings
  • On Linux: /usr/local/zed/settings/

In addition, all cameras produced after May 2026 (except the ZED Mini) store the factory calibration data directly on their internal EEPROM (reading it requires ZED SDK v5.3 or newer).

When an application opens a camera, the ZED SDK selects the calibration source in the following order of priority:

  1. The calibration file found in the settings folder.
  2. The calibration data stored on the camera's EEPROM, when no local file is available.
  3. A fresh copy automatically downloaded from the StereoLabs servers, when neither a local file nor valid EEPROM data is available (an Internet connection is required in this case).

This means that a custom calibration file generated with the tools described below always takes precedence over the factory data stored on the EEPROM.

You can also download the original factory calibration manually at any time from https://calib.stereolabs.com/?SN=<serial_number>, replacing <serial_number> with the value reported on the label on the back panel of the camera.

Using the ZED Calibration tool (stereo cameras)

You can recalibrate your stereo camera with the ZED Calibration tool, shipped with the ZED SDK. You can find it in the following folders:

  • Windows: C:\Program Files (x86)\ZED SDK\tools
  • Linux: /usr/local/zed/tools

Note: the ZED Calibration tool only works with stereo cameras; it cannot be used to calibrate a monocular ZED X One camera (see the next section).

After launching it, you can select the Tutorial, which will provide more visual instructions than this article. If you already followed the tutorial, press Start.

The calibration app works by having your ZED recognize patterns on your monitor. As such, it's best to turn off bright lights and close window blinds that may cause reflections on the screen.

Next, you'll see a grid with a red dot in the center. Aim your ZED at the monitor, and you'll see a blue dot where you're aiming. The goal is to get that blue dot to match the red dot. You'll have to do this several times as the dot moves to different positions.

Think of the dot as the light from a blue flashlight stuck to your ZED. The blue dot's size, shape and position depends on how you're holding it:

  • Bring the ZED closer to make the dot smaller, and further away to make it larger
  • Slide the ZED left, right, up or down without rotating it to move the dot
  • Tilt the ZED to slant the dot, making it more of an oval

In addition to the position of the dot, note the bars on the bottom and right sides of the window. They indicate the position of the ZED. The small gray dots on the bars must be inside the open spaces to complete each stage. This makes sure that you didn't position the dot in the right place by tilting it in the wrong direction.

When you have it positioned correctly, you'll see the red dot briefly turn into a rotating green timer. After 1 second, it'll automatically advance to the next stage.

As you go through the steps, you'll have to move the ZED further and further back, and eventually tilt it in each direction. This gives the tool a variety of reference points from which to calculate the calibration.

When finished, the tool will create a new calibration file and save it in the settings folder described above. From that moment, any application using that camera on that computer will automatically use the calibration you just created.

Using the ZED OpenCV Calibration tool (monocular cameras and custom rigs)

The ZED OpenCV Calibration tool is an open-source, OpenCV-based tool that performs a guided checkerboard calibration of both monocular and stereo cameras: single ZED X One cameras, ZED stereo cameras, and custom stereo rigs (e.g. a dual ZED X One Virtual Stereo system). It generates calibration files compatible with the ZED SDK, and can also be used to verify the quality of an existing calibration.

Use this tool in the following cases:

  • To calibrate a monocular ZED X One camera used in particular conditions (e.g. underwater, behind glass) or fitted with custom lenses; the ZED Calibration tool does not support monocular cameras.
  • To perform the extrinsic calibration of a dual ZED X One Virtual Stereo system; since each monocular factory calibration file describes a single sensor and contains no stereo geometry, this step is mandatory before depth can be estimated.
  • As an alternative, checkerboard-based calibration procedure for stereo ZED cameras.

Restoring the factory calibration

If you are not satisfied with the results of a custom calibration, you can restore the original factory calibration at any time:

  1. Delete (or move) the SNxxxxxxx.conf file from the settings folder.
  2. Open the camera with a ZED SDK application while connected to the Internet; the SDK will automatically restore the factory calibration from the camera's EEPROM (when available) or download it from the StereoLabs servers.

Alternatively, you can manually download the factory file from https://calib.stereolabs.com/?SN=<serial_number> and place it in the settings folder.