Baader M54 Extension Tube 7.5 mm This Baader extension adds 7.5 mm of optical length to an M54 threaded imaging train. It provides an M54 × 0.75 female telescope-side connection and an M54 × 0.75 male camera-side connection.
Manufacturer model: Baader M54 Extension Tube 7.5 mm · Specifications checked against manufacturer data on 2026-11-04
This Baader extension adds 7.5 mm of optical length to an M54 threaded imaging train. It provides an M54 × 0.75 female telescope-side connection and an M54 × 0.75 male camera-side connection.
The female thread is 3.5 mm deep and the male thread is 3 mm long. The manufacturer lists a 51 mm inner diameter and 59 mm outer diameter. The 7.5 mm extension is the added optical spacing, rather than the overall dimension including the male thread.
The aluminium extension provides a fixed spacing increment between compatible cameras, reducers, flatteners and other threaded accessories. Combine it with the model-specific adapter arrangement required by the optical corrector.
Baader manufacturer documentation
Exact extension SKU and nominal optical length checked against the manufacturer variant. Exact optical length takes priority over broad catalogue filter buckets. Thread engagement length is not added again to the optical spacing.
Data sheet
Specific References