Focal Reducers

Focal reducers are primarily used in astrophotography to compress the light cone exiting the telescope down to a size closer to that of the sensor within your camera. This also results in a brighter image which reduces the exposure time. Focal reducers also reduce field curvature, providing the flat field necessary for astrophotography.

Focal Reducers for Schmidt-Cassegrains

The common f/6.3 focal reducer for Schmidt-Cassegrain telescopes was originally designed to compress the existing f/10 light cone down into an area that would cover a 35mm film frame. These focal reducers are still commonly used today with CCD cameras. Note that standard focal reducers cannot be used with telescopes designed to produce a flat field because they will actually introduce an optical aberration. Specially designed focal reducers are needed for use with the Celestron EdgeHD optical system. Schmidt-Cassegrain focal reducers are equipped with a female SCT thread on the input side, and a male SCT thread on the output side.

Focal Reducers for Refractors

Focal reducers for refractors must be matched to the focal length of the instrument due to the relationship between focal length and field curvature. Some refractors, notably the TeleVue "NP" or Nagler-Petzval and Takahashi "FSQ" have inherently flat fields and should not be used with standard focal reducers.

  • Celestron Reducer - Corrector f/6.3
  • Celestron Reducer - Corrector f/6.3

  • The Celestron f/6.3 focal reducer threads onto any Celestron or Meade Schmidt-Cassegrain telescope and produces a wider field for astrophotography. read more...
  • Our price: $129.00

  • Celestron Reducer Lens .7x - EdgeHD 800
  • Celestron Reducer Lens .7x - EdgeHD 800

  • The 0.7X reducer lens for 8-inch Edge HD optics allows for both shorter exposure times and a wider photographic field of view. read more...
  • Our price: $299.95

  • Celestron Reducer Lens .7x - EdgeHD 1100
  • Celestron Reducer Lens .7x - EdgeHD 1100

  • The Celestron Reducer Lens .7x for EdgeHD 1100 makes the telescope one full f-stop faster, reducing exposure Time by one-half while increasing the true field by 43%. read more...
  • Our price: $599.95

  • Celestron Reducer Lens .7x - EdgeHD 1400
  • Celestron Reducer Lens .7x - EdgeHD 1400

  • The EdgeHD .7x Reducer for EdgeHD 1400 makes the optical system a full stop faster and reduces the focal length to a more manageable 2737 mm. read more...
  • Our price: $599.95

  • Meade f/6.3 Focal Reducer/Field Flattener
  • Meade f/6.3 Focal Reducer/Field Flattener

  • Meade f/6.3 focal reducer is used when imaging with f/10 Schmidt-Cassegrains to increase the effective field of view. read more...
  • Our price: $89.00

  • Stellarvue Reducer/Flattener for SVR102T-25
  • Stellarvue Reducer/Flattener for SVR102T-25

  • The Stellarvue SFFR102-25 reducer/flattener is optimized for the SVR102T triplet lens and threads onto the 2.5-inch focuser. read more...
  • Our price: $295.00

  • Stellarvue Reducer/Flattener for SVR102T-3FT
  • Stellarvue Reducer/Flattener for SVR102T-3FT

  • The Stellarvue SFFR102-3FT reducer/flattener is optimized for the SVR102T triplet lens and threads onto the 3-inch Feather Touch focuser. read more...
  • Our price: $309.00

  • Stellarvue SFF3-25-42 Field Flattener Field Flattener for 2.5" Focusers
  • Stellarvue SFF3-25-42 Field Flattener Field Flattener for 2.5" Focusers

  • This thread on field flattener is made for Stellarvue f/7 refractors and is available in several physical configurations. read more...
  • Our price: $329.00

  • Stellarvue SFF6 Field Flattener
  • Stellarvue SFF6 Field Flattener

  • SFF6 Stellarvue Field Flattener for f6 scopes. SV70ED, SV80ST2 and SV80S read more...
  • Our price: $265.00

  • Stellarvue SFF7 Field Flattener
  • Stellarvue SFF7 Field Flattener

  • This field flattener for f/7 refractors slips inside a 2" focuser. read more...
  • Our price: $295.00

  • Takahashi TOA-35 Flattener TOA130FN
  • Takahashi TOA-35 Flattener TOA130FN

  • The Takahashi TOA130FN flattener is for use with TOA and TSA refractors equipped with 2.7" focusers. read more...
  • Our price: $530.00

  • Takahashi TOA-35 0.7x Reducer
  • Takahashi TOA-35 0.7x Reducer

  • Takahashi has designed a high performance TOA-35 reducer for the TOA-130, TOA-150 and TSA-102/120 with a magnification of 0.7x read more...
  • Starting from: $1190.00

  • TeleVue Reducer-Flattener for TV-76 and TV-85
  • TeleVue Reducer-Flattener for TV-76 and TV-85

  • TRF-2008 0.8X Reducer/Flattener converts TV-85 to 480mm f/5.6 for flat field, fast photography. Inserts directly into 2 inch focuser, accepts standard T-rings. read more...
  • Our price: $279.00

  • TeleVue 0.8x Reducer-Flattener Body for TV102
  • TeleVue 0.8x Reducer-Flattener Body for TV102

  • TeleVue 0.8X reducer lens body for discontinued TV102 refractors. read more...
  • Our price: $299.00

  • TeleVue 0.8x Reducer for NP Scopes
  • TeleVue 0.8x Reducer for NP Scopes

  • TeleVue 0.8X reducer lens body for NP101 and NP127 Imaging System series telescopes. read more...
  • Our price: $279.00

  • TeleVue Large Field Corrector
  • TeleVue Large Field Corrector

  • TeleVue large field corrector for NP101/127 IS series telescopes. This field corrector optimizes edge of field performance when imaging with CCD chips 35mm and larger. read more...
  • Our price: $235.00

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