Go-Dome – The Worlds Finest Portable Planetariums

Newtonian™2 Mirror System

The Newtonian™2 is an optical projection system designed to be both portable and optically accurate in delivering a full-dome image. Like the Newtonian telescope, the Newtonian projection device uses two first-surface mirrors: a curved mirror and a flat mirror. In the Newtonian™2 projection system, the curved mirror is convex and displays the image from a projector over a dome. (The primary mirror of a Newtonian telescope in concave and designed to gather light and focus it onto an eyepiece). In both the Newtonian™2 projector  system and the Newtonian telescope, the flat mirror transfers the image to the mirror in the projector and to the eyepiece in the telescope. The Newtonian™2 projection system uses the Go-Vex™ first-surface convex mirror. It’s most critical design criterion is protection of the primary mirror during transport and while in projection mode

The Newtonian™2 mirror projection system serves the function of a fisheye lens at a fraction of the cost for the resolution on the dome (similar to the advantages of the reflecting telescope over the refractor). Also the Newtonian™2 has a small footprint — 60 cm wide and 30-45 cm deep (2 feet by 12-18 inches) — and is placed along the back wall of the dome, leaving the center of the dome free for visitors. It produces hemispheric coverage with a small area of shading and distortion at the back, directly above the mirror

The Newtonian™2 is designed to use an HD projector with a resolution of 1920 by 1080 or 1200 although higher resolution projectors for portable systems may become available in the future. Most of the current brands will fit in the Newtonian™2 system, but retail distributors will have complete and current lists of projectors. Brighter projectors usually have superior performance – especially in larger domes. Unlike the fisheye, which must be installed in a specific projector, the Newtonian™2 takes a range of standard HD projectors found in home theaters and conference rooms. In the HD projection over 84% of the projector’s pixels reach the dome with over 95% of the dome covered. When a projector needs repair, a second projector can replace it immediately. The Newtonian™2 rarely needs repair, but customers may change out the primary Go-Vex™ convex mirror after several years of use.

The Newtonian™2 is very portable and normally travels on top of a rolling case containing the projector, laptop and sound system – for easy transport to a school or community setting. An operator with practice can set up a Go-Dome™ and Newtonian™2 system in less than 30 minutes, with similar amount of time required for takedown.

Newtonian Alignment Grid

This HD grid is a warped polar coordinate grid. When projected onto the convex mirror, the resulting polar grid will appear on the dome. This grid allows the user to center the projected image on the mirror by moving the projector and using the controls on the secondary mirror mount. The operator then adjusts the position of the image on the dome by adjusting the tilt of the secondary mirror and the primary convex mirror. Some operators prefer a lower front spring line with the center of the projected image to the front of the center of the dome. Others prefer the image centered on the dome. Often whether the audience is on the floor or in chairs is the deciding factor

Once the Newtonian™2 is adjusted for the specific use, it will retain this adjustment with closed and stored after use.

To download the Newtonian Grid please click here


Go-Dome provides a scratch resistant, dust-repelling primary convex mirror for its Newtonian projection system (and for other mirror projection systems). This convex mirror is a precision product with seven optical coatings for even coverage, transparency, protection against yellowing, scratch-protection, and dust repelling. It will project a quality image for many years with proper protection and care.

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