Carl Zeiss Jena Sonnar 5cm f/2.0 Collapsible Contax RF Mount 前鏡片拋光 全鏡清潔 Polishing front element, Full Cleaning

我收到這支 Carl Zeiss Jena Sonnar 5cm f/2.0 Collapsible Contax RF Mount 的時候，它的狀況並不好。 前鏡片外側面有很多刮傷擦傷痕跡，內鏡片有明顯薄霧，光圈葉片也有明顯的油漬
全鏡拆解後，鏡片與光圈組件都仔細清潔，前鏡片的外側面也進行拋光處理
最後兩張是拋光前後的試拍照，是拍照的場景特別安置幾盞對著鏡頭的光源，模擬逆光的環境，逆光環境拍照可以容易的看出鏡頭的鏡片有沒有問題。兩張試拍照的相機設定都是一樣的，也都是f/2.0全開光圈。可以清楚看出拋光前後的成像有明顯的差異。 拋光前，鏡片滿滿擦拭傷痕的逆光情況下拍照，光源周圍會有明顯的光暈外溢，整體反差與色彩飽和度都偏低，照片看起來就是髒髒的感覺；拋光之後，光源周圍光暈外溢現象大幅收斂，整體畫質乾淨，飽和度與反差都大幅提升

When I received this Carl Zeiss Jena Sonnar 5cm f/2.0 Collapsible Contax RF Mount lens, its condition was not good. The outer surface of the front element had many scratches and friction marks, the inner elements had heavy haze, and the aperture blades were oily.
After a complete disassembly of the lens, both the lens elements and the aperture assembly were carefully cleaned, and the outer surface of the front element was polished.
The last two images are test shots taken before and after the polishing. For these shots, a specific scene was set up with several light sources pointed directly at the lens to simulate a backlit environment. Backlighting is an effective way to easily reveal any issues with the lens elements. The camera settings were identical for both test shots, and both were taken at a wide-open aperture of f/2.0.
The results clearly show a significant difference in image quality before and after polishing:

• Before polishing: With the element full of scratch marks, the backlit photo showed significant flaring (light halo overflow) around the light sources, and the overall contrast and color saturation were low, making the photo look "dirty."

• After polishing: The light halo phenomenon around the light sources was substantially reduced, the overall image quality is clean, and both saturation and contrast have greatly improved.