Rapid Rectilinear
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The Rapid Rectilinear also named Aplanat is a famous photographic lens design.
Aplanat photographic lens.
Enlarger
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An enlarger is a specialized transparency projector used to produce photographic prints from film or glass negatives, or from transparencies.
Staff at William Henry Fox Talbot's commercial calotype establishment in Reading, Berkshire, England. Salted paper print from a calotype paper negative, the left component of a panoramic pair of views, 1846.
Photographic enlarger.
Enlarger lens: using the aperture ring, the photographer adjusts the iris diaphragm.
Electric timer: photographers choose exposure time.