Definition of apochromat in English:

apochromat

noun

Physics
  • A lens or lens system that reduces spherical and chromatic aberration.

    • ‘There are now a few apochromats on the market that are comparable in price to similar, high-end achromats.’
    • ‘A few 9-inch and 10-inch apochromats were sold to Universities and rich individuals, the design details being kept secret.’
    • ‘Higher order spherical aberration in apochromats is a result of strongly curved lens surfaces.’
    • ‘But labels can be misleading; just as there are better quality achromats, not all apochromats are created equal.’
    • ‘The biggest problem with early apochromats, other than their sizable cost and complexity, was light loss.’

Origin

Early 20th century: from apo- + chromatic.

Pronunciation:

apochromat

/ˌapəˈkrəʊmat//ˈapəkrəmat/