CAL4

Image quality is a decisive factor in both medical and industrial endoscopy. Whether used to support clinical diagnostics inside the human body or to inspect pipes, cavities, and structural elements in home‑inspection workflows, endoscopic systems must deliver consistent, reliable, and accurately illuminated images. Evaluating this performance requires a controlled and uniform lighting environment.

The CAL4 is a 0.3 m integrating sphere engineered specifically for testing the image‑quality performance of endoscopic light sources. It provides a highly uniform illumination across a 50 mm test‑chart plane, ensuring that every captured image reflects the true optical and electronic characteristics of the endoscope.

Endoscopes (light projector systems) can be connected directly to the CAL4 via a fiber‑optic cold‑light cable, using one of four adapters compatible with the most common medical and industrial light projectors. This setup allows the endoscope’s own illumination system to evenly light the chart plane inside the sphere, enabling precise analysis of resolution, color accuracy, dynamic range, and noise.

The CAL4 is ideally paired with our D35 test charts (50 × 50 mm), including resolution, color, dynamic‑range, and noise‑evaluation targets, to create a complete and repeatable endoscopic image‑quality testing workflow.

*Light sources not included.

The CAL4 is an integrating sphere for uniform illumination when testing endoscopic camera systems.

The CAL4 supports most mainstream medical projectors; others are available upon request.

The CAL4 integrating sphere has a uniformity of >97% in the active chart area.

Image quality is a critical factor in medical imaging and endoscopic procedures. The ability to produce precise, accurate, and detailed images directly influences diagnostic reliability and procedural decision‑making. These challenges make evaluating and maintaining image quality a top priority for manufacturers of medical and endoscopic camera systems.

The CAL4 provides a controlled solution for uniformly illuminating small test targets required for testing endoscopic camera systems. To support efficient and repeatable image‑quality evaluation, we offer a variety of 50 × 50 mm test charts designed for use with the CAL4. Examples include:

• TE253 Modulated Sinusoidal Siemens Star A multi‑star sinusoidal pattern for analyzing resolution, contrast behavior, and optical performance across the image field.

• TE250 USAF Resolution Test Chart A high‑precision USAF 1951 resolution target for assessing fine detail reproduction in endoscopic imaging.

• TE240 ISO 21550 Dynamic Range Chart A standardized dynamic‑range chart for evaluating tonal response and highlight‑to‑shadow performance.

• TE188 Color Rendition Chart A compact color‑accuracy chart for assessing color reproduction, white balance, and chromatic consistency.