25mm Thermal Lens Requests: Verify the Optical Setup

A 25mm thermal-lens request needs a module-and-lens specification for the exact device. Focal length alone does not identify field of view, close-focus behavior or suitability for a particular inspection. This article does not verify a 25mm lens on a Phonemax phone.

Specify the job before selecting optics

Record the target size, available observation position, expected distance and whether the task needs scene coverage or detail on a small object. Ask the supplier to match the complete optical configuration to that requirement.

Request the supporting fields together

Use a representative sample image

Request an original image of the intended target at the stated distance. A digital zoom setting or a large saved file is not a substitute for the lens record. Do not assume the phone accepts interchangeable lenses unless the manufacturer documents that capability.

Keep the requirement unverified when evidence is missing

The P20 Pro thermal graphic gives 256 × 192 resolution, but that does not establish a 25mm focal length. A buyer should retain the missing optical field explicitly instead of guessing it from the handset's appearance.

Sources

P20 Pro product page; FLIR: detector, lens and target geometry. No independent optical test is presented.