Can lenses be interchanged on FLIR cameras? Will FLIR calibrate my lens with a Tau2 or Quark2?

Tau2 and Quark2 cameras each have unique considerations for changing lenses. Regardless of camera model, FLIR advises against customers changing lenses without first understanding the implications and consequences.

  • All FLIR cameras are factory calibrated, either with a lens or with a special aperture. It is physically possible to change lenses, however, if a different lens is installed, the original factory calibration is no longer valid. If the lens is changed without recalibrating the camera, it will work but the image performance may be degraded.
  • Several of the available lenses use different adapters to attach to the camera body, so changing lenses may require a different FLIR lens mount. Use of a third-party lens may require a custom lens mount, as well as knowledge of the back working distance, to ensure lens focus from infinity down to the minimum distance capable with the lens focus system. The design of lens mounts is critical, as a poorly designed mount may introduce unacceptable image artifacts. As a result, FLIR cannot be responsible for the performance of third-party optics used with its cameras, nor can FLIR provide optical design information or support for other than the existing lens mounts.
  • Yet another consideration is the expected frequency of lens changes. Most of the lens adapters used on Tau2 and Quark2 are thread-mount. Repeated removal and installation of lenses by unthreading and rethreading can result in debris being deposited onto the surface of the sensor. In some cases FLIR recommends changing the lens mount rather than just the lens itself, however repeated removals and reinstalls of the lens mount will weaken the integrity of the camera frame over time.

For qualified customers, FLIR can make an Advanced tab available through the camera control GUI. The features of the Advanced tab include the capability to perform lens calibrations on Tau2 and Quark2 cameras. This field-calibration process requires the use of at least one blackbody source (a uniform, controllable temperature reference) that has an area greater than the diameter of the front of the lens. The calibration routine calculates gain terms on a per-pixel basis with the customer-supplied lens attached to the camera body, and stores the customer-performed calibration in non-volatile camera memory. A PDF file describing the process is here: Gain Cal App Note
Tau2 324 and 336 cameras have three memory locations for lens calibration data. Tau2 640 cameras have two memory locations for calibration data. These locations can be accessed via the GUI, or by serial command. Tau2 cameras have different holders for wide FoV lenses and narrow FoV lenses.

Although Quark2 has the same memory features as Tau2, FLIR does not recommend changing lenses on Quark2. This is because the sensor package is extremely sensitive to debris that may be introduced when a lens is removed or installed. Any lens calibration activity should be performed in a clean room environment by qualified technicians or engineers.

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