About the Upgrade | CCNY Planetarium

About the Upgrade

• James Hedberg

Installing a new projection system

We will be installing a spherical mirror projection system over the existing Spitz 512 instrument. The spherical mirror system will allow us to show digital media on the dome, without a major overhaul of the infrastructure.

The basic concept involves redirecting a projector’s beam to the entire surface of the dome using a hemispherical mirror.

spherical mirror schematic
A basic spherical mirror schematic illustration.

The schematic shows the idea. Rays coming from the projector will be reflected from the spherical mirror and directed to the entire dome.

Our installation will require another planar mirror so that the projector doesn’t have to be cantilevered out into the middle of the dome. This increases the stability of the projection system, at the expense of the little brightness.

spherical mirror schematic
Rendering of the plans

We will also make some improvements to the audio systems in the room.

Hopefully, it all goes swimmingly!