A couple weeks ago some of our forum members were talking about using a shutter system for their DLP setups. Using a shutter would prevent extra light from being emitted toward the build area when printing isn’t taking place, and in-between projected layers during printing. Some resins are so sensitive to light that this process is actually necessary. This is done most simply with a hobby servo and something to act as the shutter material. Preferably something that can block light very well. In our case we laser cut some acrylic, we also engraved an area deeply so that the servo output hub would grip the acrylic very well.