Assertion: clark lens | /r/CapableOf | create a focus mismatch
Facets:
value: slightly shorter than r
type: OTHER
value: by about 1880
type: TEMPORAL
value: between r
type: LOCATION
Source sentences:
text: By about 1880, Clark lenses had R 3 set slightly shorter than R 2 to create a focus mismatch between R 2 and R 3 , thereby reducing ghosting caused by reflections within the airspace.