Adam's Lighting Info: Down Lights or Wall Washers?

When lighting a room using down lights, you must consider how you intend to handle light on the vertical surface of the walls. A down light will direct light straight down, and a wall washer will ideally graze the wall from ceiling to floor. While this may be an obvious statement, the wall washer is often forgotten or misunderstood when it comes to lighting a room. If down lights are needed near the wall, depending on the situation, utilizing a wall washer is an effective tool to eliminate the "cave" and "scalloping" effects that down lighting can provide when grazing a wall. One mistake that is made with down lights in regards to walls is the idea that mounting the light closer to the wall will more effectively wash the wall. This practice will result in a hot (bright) spot on the wall close to the ceiling, and not eliminate the scallop.

By using a combination of wall washers around the perimeter of the room, and down lights in the center, a room can be lit without odd scalloping on the walls. Some may argue that scalloping the wall with even spacing of fixtures can create a visual interest, it can also be argued that this is actually taking away from design elements in the room by the interior designer, architect, or end user.

One application that uses wall washers often is video conference rooms. Cameras can exaggerate lighting conditions to appear either under or over lit. By providing an evenly lit wall, the camera will not be confused as to which lighting level it should adjust its levels. Also the background for the subject will not be dark, creating a more natural look for the video call.

Below is a photo comparison between a 6 inch LED down light and a 4 inch LED wall washer mounted at 8.5 feet above the finished floor. In these photos you can see the difference between the cave effect the down light provides and the wash that the wall washer provides.
Please note that both are not permanently installed, and the wall washer is being affected by having its trim above the ceiling grid. As you can see in the second photo, the light is being interrupted by the grid which results in a shadow at the top of the wall.
Click the pictures to enlarge.