(of a lens) maintaining focus even if magnification is changed
parfocal in American English
(pɑːrˈfoukəl)
adjective
Optics
of or pertaining to different eyepieces (of telescopes or microscopes) that all focus their images in the same plane, so that they can be interchanged without readjusting the instrument
Word origin
[1885–90; par1 + focal]This word is first recorded in the period 1885–90. Other words that entered Englishat around the same time include: booster, scrum, sensitization, toner, upsweep