Adds a fixed height of 1.25" or 2.25" to a focuser base Designed for 3.0" diameter Starlight Instruments focuser bases Ensures focuser can reach the focal plane on custom-built telescopes Solid, single-piece aluminum construction prevents flexure Description FAQ Specifications In the Box Warranty Starlight Instruments 3.0" Diameter Riser The Starlight Instruments 3.0" Diameter Riser is a precisely machined spacer that adds either 1.25" or 2.25" of height to a compatible 3.0" Feather Touch focuser base, providing the critical extension needed to reach focus in custom Newtonian telescopes where the focal plane sits far from the tube wall. Bridge the Focus Gap with a 1.25" or 2.25" Riser When building a Newtonian telescope or modifying an existing one, the final position of the focal plane can require placing the focuser higher than a standard base allows. This riser solves the common problem of insufficient out-travel by physically raising the entire focuser assembly by a fixed 1.25" or 2.25", ensuring you can achieve a sharp focus with any eyepiece or camera. Machined to the same exacting tolerances as Feather Touch focusers, this riser integrates seamlessly between the focuser base and the focuser body. This creates a rigid, tilt-free connection that maintains collimation and supports the weight of a heavy imaging train without introducing flexure. Correct Focal Plane Alignment: Use the 1.25" or 2.25" riser to match your focuser's travel range to your telescope's specific focal point. Solid, Stable Connection: Provides a non-flexing extension for heavy eyepieces, binoviewers, or imaging cameras. Seamless Integration: Designed to fit perfectly with Starlight Instruments 3.0" diameter curved or flat focuser bases. What is the purpose of the Starlight Instruments 3.0" Diameter Riser? The riser adds a fixed height (either 1.25" or 2.25") to a 3.0" Starlight Instruments focuser base. This is necessary on some telescopes, particularly custom-built Newtonians, to ensure the focuser has enough outward travel to reach the focal plane with various eyepieces or cameras. I'm building a 12" f/4 Dobsonian and my eyepiece won't reach focus. Is the 3.0" Riser the right solution? Yes, this is the exact scenario the riser is designed for. If your focuser runs out of outward travel before achieving a sharp image, adding a 1.25" or 2.25" riser will lift the entire assembly. This effectively moves its travel range outward to meet the focal plane of your 12" f/4 system. How do I know if I need the 1.25" or 2.25" Starlight Instruments Riser? To choose the correct riser, measure how much more "out" travel you need from your focuser's current maximum position to reach focus with your longest focal length eyepiece. If you need about an inch of extra travel, choose the 1.25" riser. If you need closer to two inches, the 2.25" option is the correct choice. Is the Starlight Instruments 3.0" Diameter Riser compatible with other brands of focusers? This riser is specifically designed for the bolt pattern and diameter of Starlight Instruments 3.0" focuser bases. It is not guaranteed to be compatible with focusers or bases from other manufacturers. Will adding the 3.0" Riser to my 16" truss-tube Dobsonian introduce flexure with a heavy camera? No. The riser is machined from solid aluminum to the same high standards as Feather Touch focusers. It creates a rigid mechanical connection between the base and the focuser, preventing tilt or flex, even with heavy imaging trains on a large instrument like a 16" Dobsonian. Does the Starlight Instruments 3.0" Riser come with mounting hardware? Mounting hardware is typically supplied with the focuser and focuser base. The riser is a spacer that fits between these two components, and you will generally use longer screws (not included) to accommodate the added height. Product Type Focuser Riser / Spacer Compatibility Starlight Instruments 3.0" Diameter Focuser Bases Available Heights 1.25", 2.25" Diameter 3.0" Material Anodized Aluminum 3.0" Diameter Riser (1.25" or 2.25" Height) × 1 Starlight Instruments 2-Year Warranty
