Designing for Dome projection and the need for a standardized bottom frameline in projection.

A brief essay by Ben Shedd ©1994/1997 Posted 10/27/08 Updated: 02/22/10

The giant dome and flat screens create a new visual space for film makers to show work. I believe the giant screens are to be considered frameless visual space, and all imagery needs to be designed from the center out.

The film image for the dome is optimized by designing with a strong center of interest and as if there are no side or top edge/frames. Images are placed in the lower center. Objects only enter from the top (overhead) or bottom of the frame, not the sides.

The only film frame edge where objects can extend outside the “frameline” is the lower edge of the image, which is hidden by the audience.

I direct for large screen visual space as follows: the upper portion of the image is overhead space, and needs appropriate sky or natural horizontal overhead images. This consideration minimizes projector related image distortions. The side areas of the frame are considered peripheral space and do not carry primary images of audience interest. These visual areas are utilized to surround the audience with the place. I seek strong natural frames within the real imagery to direct the audience view, and place my images in the central screen area. In order to increase the color saturation of the projected image, the upper screen area must be keep somewhat dark to lower unnecessary screen cross-bounce on the lower screen area.

I seek effective lighting to enhance the depth shape of projected images and insist on the sharp focus from the foreground to the midground. Depth of focus is a key consideration in choosing photographic imagery. Depth of field is reduced when imagery is stretched across the large canvas of the dome screen and this consideration needs to be designed and monitored for its final effect on the giant screen.

With huge frameless images projected on the wrap-around dome screen, any camera movement in the images creates the imaginary sensation that the theater/seats/audience are moving/flying/tipping/tilting and all the camera action appears to happen on the audience’s side of the screen. This also means that audiences imagine they grow and shrink when large or small things are projected on the screen and there needs to be appropriate intermediate scaled imagery or film elements to maintain these perceptions.

Images and sequences designed in the above manner create an effective dome experience and translate well to giant flat screened projection. They are very effective in both formats.

The single common frame of reference in all giant screen projection is the placement of the bottom frameline.