extrafocal

1 9.1

An image that appears outside the area where a lens focuses light

adjective
/ˌɛkstrəˈfoʊkəl/

Specialized

: extrafocal

Researchers studied the extrafocal regions to understand the lens's optical properties.

Examples

The technician adjusted the lens to correct the extrafocal blur.
An extrafocal image appears when the camera is not properly focused.
The extrafocal light created an interesting effect in the photograph.
In this lens, the extrafocal areas can appear blurred.
In optics, the extrafocal image can appear distorted and colored differently than the focused one.
The analysis revealed that objects located in the extrafocal area produced varying optical effects.
When adjusting the lens, the extrafocal rays created a noticeable difference in clarity and color.

Surface Forms

extrafocal positive

Morphology

extrafocal = focal (transparent) = extra + focal

The prefix 'extra-' clearly indicates 'outside' or 'beyond', and when combined with 'focal', it transparently means 'outside the focal point'.

Etymology

The word extrafocal comes from the parts extra- meaning 'outside' and focal from focus, meaning 'center' or 'point'. So, extrafocal describes something 'outside the focus', like a blurry area around the center of a photo when the camera is not properly focused.