EntityQ3880557· pop 26· linked from 235 articlesobjectiveSign in to saveoptical element that gathers light from the object being observed and focuses the light rays to produce a real imageConnectionsOil immersionEntityInternational Standard Book NumberEntitymirrorEntitytelescopeEntitymicroscopeEntityinfinityEntitycameraEntitylensEntitybinocularsEntitymagnifying glassEntityfluoriteEntityfocal lengthEntityrefracting telescopeEntitycamera lensEntityfocusEntityeyepieceEntityW. M. Keck ObservatoryEntityoptical aberrationEntitychromatic aberrationEntityreflecting telescopeEntityCategoriesLensesMicroscope componentsOptical microscopy