The SVX180T was designed for the future. Instead of using a full length main tube, we have made all Stellarvue 180 refractors with a slightly shortened main tube and placed an extension between the focuser and the main tube to compensate for this. We did this anticipating the need for wide field binoviewing and possible, future, wide field optical reducers. The idea was to be able to remove the supplied extension tube in order to move the focuser closer to the objective. While binoviewers can be used with the SVX180T with the supplied entension in place, a glasspath or OCS corrector is needed in order for the binoviewer to come to focus. This increases the magnification, reduces the field size and adds more glass to the image train. These correctors are not needed if one removes the extension and replaces it with our new WFB adapter. Removing the extension compensates for the additional lightpath within the binoviewer. 



Stellarvue refractors are precision aligned with adjustable flanges on both the objective end and the focuser end. The extension tube connects to the focuser adapter and we adjust alignment on the focuser end using our custom focuser adapter. In order to maintain alignment, it is necessary to keep both the extension tube and focuser adapter together as they are adjusted to the telescope objective here at the factory. The WFB adapter comes with it's own focuser adapter as shown above.

To replace the extension with the WFB adapter:

Step 1: Remove the focuser from the focuser adapter

Step 2: Remove and store the the focuser adapter and extension from the telescope tube. Keep these two components together and DO NOT mess with the adjustment set screws!

Step 3: Install the WFB adapter (which includes its own focuser adapter)

Step 4: Reinstall the focuser to the WFB adapter as shown above.