GSO extension tube for RC telescopes M117 - 25 mm lengthTo bridge the back focus of GSO 10" / 12" RC telescopes and Officina Stellare RC telescopes
RC Telescopes by GSO have a long back focus making this system ideal for the use of off-axis guiders and / or focal reducers. But in standard use, the long back focus may have problematic side effects: In many applications, the focuser must be extended totally and it still needs extension then. This is neither optically nor mechanically a recommendable solution.
The GSO extension tubes are placed between telescope and focuser
The advanteges of this solution can be seen clearly: The focuser is always in an optimal position and needs no further extension with a sometimes problematic lever arm. The free aperture is significantly larger.
GSO Extension Tube for the GSO RC 10" and 12" Telescopes - Length 25 mm.