Baader Planetarium IMP85 Adapter S120a to IR90 Focuser Short (20mm)

The IMP85 System: 3 Ports, 1 Straight-Through Optical Path

Developed for remote observatory automation, the IMP85 instrument selector eliminates the need for manual equipment changes. This adapter allows you to integrate that system with your IR90 focuser. The core design provides a central, un-mirrored Port 1, ensuring your main astro camera receives 100% of the light from the telescope's optical axis without any degradation from a flip-mirror.

This is critical for remote observatories that can't be physically reconfigured, or for public observatories that need to switch from an imaging camera to a visual eyepiece for guests in seconds. Once installed, your telescope can be used for deep-sky imaging, planetary video, and spectroscopy without ever detaching a camera.

Electronically Switched Optics: Two 40x40mm Fused Silica Mirrors

To access Ports 2 and 3, the IMP85 electronically inserts one of two 40x40mm fused silica mirrors into the light path. These high-quality mirrors redirect the telescope's focus to a secondary or tertiary instrument with exceptional repeatability. This means you can confidently switch between instruments knowing that focus and alignment remain consistent.

The ports are designed with a clearly defined backfocus, allowing you to use standard adapters to make your various instruments parfocal. This minimizes refocusing time when switching between your main camera and your guide camera, spectrograph, or video camera.

IR90 Focuser Adaptation: A Compact 20mm Connection

This specific component, the S120a to IR90 adapter, is the mechanical link between your telescope and the powerful IMP85 system. It is engineered to provide a secure, non-flexing connection to focusers using the IR90 standard. With an optical path length of just 20mm, it helps conserve precious backfocus, which is often critical when building complex imaging trains with multiple components.