1.
focal point (optics)
The point at which rays of light converge after passing through a lens or reflecting from a mirror. A technical term in optics and photography.
カメラの焦点を合わせる。
Adjust the camera's focus.
レンズの焦点距離が長いほど遠くのものを大きく撮れる。
The longer the focal length of the lens, the larger you can photograph distant objects.
虫眼鏡で太陽の光を焦点に集めると、紙が燃える。
If you focus sunlight to the focal point with a magnifying glass, the paper will burn.
2.
focus, central point (of attention or discussion)
The main point of attention, discussion, or concern. The most common usage in everyday language.
議論の焦点がずれている。
The discussion is off focus.
選挙の焦点は経済政策に移った。
The focus of the election shifted to economic policy.
裁判では、被告の動機が焦点となっている。
In the trial, the defendant's motive has become the focal point.
USAGE:
The figurative sense (focus of attention) is far more common in everyday language than the optical sense. The expression 焦点を合わせる works for both senses — literally focusing a lens or figuratively directing attention.
COMMON COLLOCATIONS:
- 焦点を合わせる: to focus, to bring into focus
- 焦点を当てる: to focus on, to spotlight
- 焦点がずれる: to be off focus, to lose focus
- 焦点距離: focal length
- 議論の焦点: the focus of discussion