TS-OPTICS
Distance tube with 25 mm length for telescopes with M90x1 connection thread.
Available Upon Request
This includes products that we do not keep in stock but are only available upon request or have been announced in advance by the manufacturer. These items are usually shipped within 5-14 days. Once we receive your order, we will notify you by e-mail or telephone of the exact delivery time, as well as the amount of any deposit that will be required.
25 mm EXTENSION ADAPTER FOR M90x1 THREAD
Many telescopes, for example Ritchey-Chrétien telescopes, have much backfocus. This generous distance of the focus allows using a focal reducer or accessories like off-axis guiders. But if you want to attach only a camera or possibly just to do direct-vision observations, than the focuser has to be completely extended and additional 2" extension tubes have to be used. That reduces stability.
This M90 extension solves the problem. It is threaded between focuser and telescope and increases the distance betweeen telescope and focuser.
The focal plane or focal point moves closer to the focuser and you don´t need to extend the drawtube that much. For attaining precise matching, you can also thread several M90 extension tubes together. A further advantage is the better illumination. The clear aperture of the extension tube is clearly larger than the clear aperture of a 2" extension tube.