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Stellarvue Reducer/Flattener for SVR90T with 2.5" Focuser - SFFR90-25

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SKU: STV-SFFR90-25

Stellarvue Reducer/Field Flattener for SVR90T w/2.5" Focuser

Optimized for the Stellarvue SVR90T Triplet Refractor, this reducer/field flattener threads into both 2.5" Stellarvue and Feather Touch focusers. Offers 0.8x focal reduction to transform the 90 mm f/6 into an f/5.6, cutting the focal length to 504 mm.

Uses standard 42 mm filter thread to allow standard 2" filters to be added for imaging. This unit has a backfocus of 55 mm. Because a DSLR camera with t-ring also has a 55 mm backfocus, thread this reducer/flattener into the camera's t-ring and then attach it to the focuser as depicted in the images section.

For those using a CCD camera, an additional set of extension tubes may be necessary depending on the camera's backfocus. Knowing the amount of distance there is between the T-thread and the CCD chip is essential. The distance between the back of the field flattener and the chip must remain at 55 mm. For example, if a CCD camera with 35 mm backfocus is used, a 20 mm extension will be needed.