This British Standard is an adoption of an ISO standard. You can access the ISO version here.
ISO 14490‑9 is the ninth part of the ISO 14490 series that discusses optics and photonics.
ISO 14490‑9 specifies the test method for the determination of the deviation from a flat image surface, i.e., the sagittal and tangential field curvature of telescopic systems and observational telescopic instruments.
ISO 14490‑9 - Test methods for field curvature is useful for:
Field Curvature, also known as “curvature of field” or “Petzval field curvature”, is a common optical problem that causes a flat object to appear sharp only in a certain part(s) of the frame, instead of being uniformly sharp across the frame.
ISO 14490‑9 provides you with methods for testing field curvature. The guidelines of ISO 14490‑9 enable you to take high-quality pictures. ISO 14490‑9 helps you produce better quality digital cameras that minimize or eliminate the issue of field curvature.