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This is the third installment of the SCT Corrector from Starizona. This reducer has been given small optical enhancements over it's predecessors as well as the standardization of the top thread to M42 for easier customization.
Focal Length
The exact focal length of the reducer/telescope combo depends slightly on where in the optical path the SCT Corrector lens is placed. Nominally it will be within a few mm of the rear threads on the telescope. Changing this distance should only affect the focal length, not the optical quality. Listed below are the nominal focal lengths for the various sizes of Celestron SCTs*. The SCT Corrector works great on standard f/10 Meade SCTs without the newer ACF optics as well.
Telescope // Focal Length // new Focal Ratio with SCT III Reducer
C6 // 1220mm // f/8C8 // 1450mm // f/6.8C9.25 // 1490mm // f/6.3C11 // 1760mm // f/6.3C14 // 2365mm // f/6.7Features
0.63x focal reduction factor
2.5x faster than SCT's native f/10
1.4x faster than original f/7.5 SCT Corrector design
27mm image circle
2" barrel
threaded for 48mm filters
SCT Corrector Top Thread: M42 x 0.75mm T-thread
mechanical Backfocus (thread shelf to focal plane): 90.3mm (3.56”)
black anodized, machined aluminum housing
fully multi-coated optics
improved 4-element optical design