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Baader Flip Mirror II

SKU 2458055

Availability: Immediate Dispatch

  • Baader-FlipMirror II (BFM II) with three ports:
    • Straight-through (M48/T-2 on both sides) for full-frame camera, spectrograph, or other instruments
    • Top-mounted T-2-thread for eyepiece holder, video-module (up to 32mm diameter fov) - or even a binocular-viewer
    • Bottom-port prepared to accept the optional Baader Off-Axis-Guider prism-assembly (part of RCC-OAG #2956950) or an optional ThAr-lamp for motorised intermittent calibration of spectra
  • Precision first surface mirror w. Enhanced-Al coating, for discriminating work w. small pixel cameras
  • Backside of flip-mirror is also Al-coated and masked, to direct the light of an optional spectral calibration-lamp onto a spectrograph-slit
  • Designed to enable precise adjustment of all optical pathways
  • Shortest backfocus for each application - utilizing the wealth of adapters of the Baader Astro T-2 system, M48 system and UFC system
  • front and rear M48 rotation-adjustment rings made from hardened stainless steel, matched to the BFM main body for zero play and for rotating and locking the BFM main-body in the optimum rotational alignment with any conceivable accessory equipment
  • Readily accepts the Baader Universal Filter Changer system of parts (UFC system)
  • Prepared to accept an optional motorised timing belt - as a core-tool for remote imaging, guiding and spectroscopy

If you are an observer and an imager, then having to swap instruments (cameras, eyepieces) is a reality because every telescope just features one "exit" port.  Improving your workflow, especially during astrophotography is the goal set out for the Baader Flip Mirror II (BFM II). The BFM II is not just a simple flip mirror but much more, as unlike other flip mirrors, there are three ports.

Baader Flip Mirror II

  • The BFM II allows a variety of permanent adaptations to your telescope 1 .
  • Use the rotary knob 2 to switch between the rear port 3 and the top port 4; you can use an optional toothed belt to operate it with a motor (not included).
  • An autoguider or a calibration lamp can be connected to the bottom port 5.

General Function of the FlipMirror II Star Diagonal

Baader Flip Mirror II

The BFM II lets you switch between a straight light path (Position A) for a camera or other measuring instruments and an angled light path (Position B), e.g.
for an eyepiece. The following figure shows how it works. In addition, a calibration lamp for spectrographs or an Off-Axis-Guider pickoff-prism (that is not affected by the mirror position) can be connected at the AUX-port on the bottom

Scope of Delivery of the Baader FlipMirror II Star Diagonal:

  • Baader FlipMirror II Star Diagonal – with fine-optically polished, movable mirror
  • Laterally adjustable T-2a top ring
  • 2x M48i / S52 Dovetail ring made of hardened stainless steel # 2958552
  • Reducing ring M48a / T-2i # 2958553
  • Reducing ring M48a / T-2a # 2958554
  • Inverter ring M48a / M48a # 2958555
  • Pin type face wrench for M48 / T-2 and M4 counter nuts
  • 3 mm screwdriver for M 4 brass adjustment screws
  • 4x hex keys (2.5 / 2.0 / 1.5 / 1.3 mm). The 2.0 mm wrench has a ball head to reach screws even when accessories are mounted by holding the wrench at an angle.
  • Bottom flange (laterally adjustable 1mm) for off-axis guide or calibration lamp for spectroscopy
  • Dust cap for bottom flange
  • 2 x M48 dust caps
  • T-2 dust cap
SKU (#) 2458055
INNER CONNECTION (LENS SIDED) Thread, Dovetail ring clamp, S52, T-2 (M42 x 0,75), M48
INNER CONNECTION (EYEPIECE/-CAMERA-SIDED) Thread, Dovetail ring clamp, M48, S52



BFM II User Manual