Carl Zeiss Biogon 35mm f/2.0 ZM 對焦環/對焦螺紋轉動不順 重新潤滑 Re-grease the stiff focus ring/focus helicoids

這支 Carl Zeiss Biogon 35mm f/2.0 ZM 的對焦環轉動不順，原因是對焦螺紋上的潤滑油脂乾了，只需要徹底清潔對焦螺紋後，再上新的潤滑油脂 便可讓它恢復正常順暢的工作狀態。 蔡司ZM系列的鏡頭都有對焦環乾澀轉動不易的通病，只要適當處理，問題是很容易解決的！

This Carl Zeiss Biogon 35mm f/2.0 ZM had a problem of stiff focus ring. The main reason was the dry grease on the focus helicoids. It is easy to be solved by thoroughly cleaning the helicoids and applying new grease. The stiff focus ring is a common problem for Carl Zeiss ZM lenses, and can be restored easily by qualified repairman.