Assertion: astigmatism | /r/AtLocation | a lens system
Facets:
Source sentences:
text: When astigmatism is present in a lens system, the tangential field departure from the Petzval surface is three times larger than that displayed by the sagittal field.
text: When astigmatism is present in a lens system, the tangential field departure from the Petzval surface is three times larger than that displayed by the sagittal field.