Baader Planetarium Baader Solar Projection Screen (BSPS)

The Baader BSPS is perfect for outreach. You can attach it to a small guide scope or finder scope that is aligned with your main telescope (which should have its own dedicated solar filter). This allows you to show a projected image of the Sun to people waiting in line, keeping them engaged while also confirming the Sun is still centered for the person at the main eyepiece.

Yes. After pointing your telescope at the Sun with the BSPS attached, simply turn off the mount's tracking. By observing the direction the Sun's image drifts across the screen, you can determine your polar alignment error. The drift direction tells you precisely how to adjust the mount in altitude and azimuth for a much more accurate alignment, a task that is typically difficult to perform in daylight.

The Baader BSPS is designed with safety as the top priority. It creates a closed, enclosed system from the eyepiece to the screen. This prevents anyone from accidentally putting a hand or eye in the focused, intense light path, which is a significant risk with open projection methods.

The BSPS is ideally suited for refractor telescopes. To minimize heat build-up in the star diagonal and eyepiece, telescopes with faster focal ratios are recommended. For refractors with large apertures, it's advisable to use an aperture stop to reduce the heat load during long observation periods.

To use the Baader BSPS, you will need the following:

• A telescope suitable for solar projection (ideally a refractor).
• A star diagonal or prism with a 2" nosepiece connection.
• A variable eyepiece projection adapter with a T-2 thread (like the Baader OPFA).
• A glass/metal eyepiece suitable for solar projection (like a Baader Classic Ortho).

Yes, some assembly is required. The Baader BSPS kit includes the screen, a T-2 adapter, and a pre-cut cardboard housing that you assemble. For users wanting a more permanent housing, Baader also provides STL files so you can 3D print a plastic version yourself.