The title retains the document edition where identified. Research check dates are not publication dates. Consult the PDF for printed revision and process conditions.
Speed, formats, characteristic product attributes and distribution context support a Portra 400 rebrand inference. Checked Kodak launch/product pages do not declare exact chemical or coating-revision identity.
Still needed: Obtain a brand-issued exact product/coating crosswalk or inspect a documented, dated retail roll and base-stock control.
A solid connection establishes the stated relationship, such as a respool or family variant. It does not establish unchanged resolution, processing or coating generation. Dashed connections retain the identity uncertainty.
Results below use a 36 × 24 mm image area and ideal two-sample spatial sampling. Approximate graph readings retain their source process; a color-layer envelope is not an uncertainty interval.
Approximate graph reading
Approximate MTF50
~5.4–18.1 MP
39.6–72.5 cycles/mm · 36 × 24 mm
Manufacturer plot conditions; see full source page.
Original unit: cycles/mm. Spatial frequency from the labeled MTF axis.
Derivation: graph digitized vector. Formal uncertainty is not established for digitized curves.
Inspect annotated chart excerpts
Audit excerpts show approximate threshold readings across several source films. Follow the source-page link for this film’s complete axes, process and legend.
Manufacturer curves and exposure guidance. No PARVEC-style saturation percentages.
Historical editions, coating revisions, development and retail batches retain their own scope. Research supplements do not change the main color-film catalog.
