Takahashi RD‑EXT 98 mm – 20.1 mm Extension (TKA86596)

Takahashi RD‑EXT 98 mm – 20.1 mm Extension (TKA86596)

Shorter yet equally vital, this 20.1 mm extension ring supports precise back-focus control on 98 mm systems. When minor distance adjustments are needed after adding or removing filter wheels, this ring corrects optical spacing without disrupting the rest of the assembly.

Perfectly complementing its 33.2 mm sibling, the 20.1 mm sleeve helps imagers fine-tune their trains for the sharpest edge stars and optimal parfocal performance.

Cloudy Nights Community Insight:
Users emphasize its role in “fine-tuning focus without backing out the focuser”—a relief for anyone troubleshooting daytime or evening focus transitions.

Observing Tip:
Choose this ring for marginal focus adjustments after changes in the camera or accessory load. It preserves tight focus and star shape without forcing drastic mechanical moves.