As stated above, testing at several locations should be done to evaluate what works best for your installation. Also, camera body type, lens and zoom settings may also play a part in achieving success.
Have tried two locations for this 15 watt white LED 12 volt landscape light. Note: The lamp is set at 4000K to match the color temperature of the street light that is not visible in the image.
1) First tested location was with the light mounted to the left of the camera at the same height. When using this location the light has a tendency to blind the person walking on the sidewalk when looking at the camera. No effect on image quality.
2) As shown in the below image, the camera is mounted below the same light. In this scenario, the light illuminates the camera making it very visible at night which acts as visual clue that there is a camera. No effect on image quality.
As a side note, the camera is the Dahua 180 degree model.