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Solar Spectrum Research Grade 0.4x Telecompressor

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SKU 2459260

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  • Alike the TZ-3 telecentric, also the RG 0.4x Telecompressor features 46mm clear aperture throughout, perfectly suitable even for large SolarSpectrum RG46 Research Grade H-alpha Filters
  • Working distance: 74mm (Distance to the camera sensor), optimized for videography and full solar disc imaging. Ø 16 mm corrected image field in conjunction with the TZ-3
  • mounts straight onto the body of the SolarSpectrum filter and reduces f/30 f/ratio back to f/10, thanks to the factor of 0.4
  • 2" male threads on both sides, fitting the SolarSpectrum Universal Flange Adaptor #2958240 (included as standard on both sides of the SolarSpectrum H-alpha filters)
  • The RG 0.4x Telecompressor serves to adjust the focal length in order to improve poor seeing conditions and / or to enlarge the field of view for photographic- or lucky imaging applications

Solar Spectrum H-alpha filters require parallel light with a ray path of at least f/30. This is achieved by a focal length with our telecentric systems (and possibly also by dimming the lens with the iris). Because of the focal length extension in many telescopes the sun is not completely visually apparent when using eyepieces with f = 30 to 35 mm.

Note: both Baader Solar Spectrum Telecompressors are mounted straight onto the Solar Spectrum body rear end and reduce the f/30 ratio by a factor of 0.4x. As a result, a much larger portion of the solar surface comes into view, depending on the size of the Etalon mounted inside the Solar Spectrum filter.

A telecompressor is used to adjust the focal length to possibly poor seeing conditions and / or enlarging the field for photographic- or webcam applications.

To attach the telecompressor use our 2″ Universal flange (# 295 8240); it gets attached with four screws directly onto the filter housing (see illustration), the telecompressor is mounted directly into the 2″ thread of the universal flange. The main thread of the compressor also is a 2″ male thread. This can be changed if necessary with parts from our T-2 accessories system either to a T-2 internal or external thread.


MANUFACTURER Baader Planetarium
SKU (#) 2459260
EAN CODE 4047825008671
WEIGHT (KG) 0.105