# Why is there a distinct boundary between light and dark in the scene after using rect/strip lights?

![image](https://docs.d5render.com/~gitbook/image?url=https%3A%2F%2F3611830798-files.gitbook.io%2F%7E%2Ffiles%2Fv0%2Fb%2Fgitbook-x-prod.appspot.com%2Fo%2Fspaces%252F-MjbN1iGmN_HBnj_fyU9%252Fuploads%252F2DSXd2TucvBY5WSbt7OT%252Fimage.png%3Falt%3Dmedia%26token%3D778b4ffd-1918-49e6-b8c4-f0d4e5e7ffc9&width=768&dpr=3&quality=100&sign=d85ced4d&sv=2)

the light overlaps with the top surface

This phenomenon may occur if the rect/strip light overlaps with the model; please adjust the position of the light source slightly to get the normal effect.

![image](https://docs.d5render.com/~gitbook/image?url=https%3A%2F%2F3611830798-files.gitbook.io%2F%7E%2Ffiles%2Fv0%2Fb%2Fgitbook-x-prod.appspot.com%2Fo%2Fspaces%252F-MjbN1iGmN_HBnj_fyU9%252Fuploads%252Fh4zkdMMUHZC04xQWXXKm%252Fimage.png%3Falt%3Dmedia%26token%3D9d88c1c4-4a2b-4355-9bad-a1f1596632fd&width=768&dpr=3&quality=100&sign=f64984db&sv=2)

the light moved down slightly, do not overlap with model