focal point

noun

Also called principal focus. Optics. either of two points on the axis of a mirror, lens, or other optical system, one point being such that rays diverging from it are deviated parallel to the axis upon refraction or reflection by the system and the other point being such that rays parallel to the axis of the system converge to the point upon refraction or reflection by the system.

the point at which all elements or aspects converge; center of activity or attention:

The focal point of our discussion was the need for action.

the central or principal point of focus.

Origin

1705-15

Examples from the web for focal point

Although designed to focus solar energy towards a single focal point to boil a liquid and drive a steam generator.
Its of a wilderness landscape with a couple of stags for the focal point and deers.
The composition should naturally take a viewer's eyes to the focal point, but it is not the case with this photograph.
The arrest instantly became a new focal point in the long-running debate about how to restructure scholarly publishing.
Social context is obviously key to any serious exploration of the case, and will be a focal point of the conference.
The flame provided a target and a focal point for the camera.
If people knew this, their nutrition would become a focal point with marked results.
But there was no band, no focal point to the celebration.
The city lacks any focal point of the sort that might catalyze a spontaneous public gathering.
They charged modern poetry with cultural importance and made it the focal point of their intellectual discourse.

British Dictionary definitions for focal point

focal point

noun

Also called principal focus, focus. the point on the axis of a lens or mirror to which parallel rays of light converge or from which they appear to diverge after refraction or reflection

a central point of attention or interest

focal point in Medicine

focal point n.
See focus.

focal point in Science

focal point
The point at which all radiation coming from a single direction and passing through a lens or striking a mirror converges. Also called focus.