Lens Comparison: Carl Zeiss Jena Sonar 85/2 T vs Jupiter-9 85/2 MC

2026/5/16

After taking the Soviet Jupiter-9 85mm f/2 MC (M42) out for a photo walk last time, I thought it would be interesting to compare it directly with the West German Zeiss-Opton Sonnar 85mm f/2 T (Contax RF), which led to this test record.　I mounted both lenses on Sony E-mount adapters for the comparison. In terms of physical size, the Jupiter-9 is about 1–2 mm taller. When stopped down to f/4, the Jupiter-9 maintains an almost perfectly circular aperture shape, while the Zeiss-Opton produces a more polygonal, star-like diaphragm opening. As for weight and handling, the two lenses feel fairly similar in hand.

上次帶著蘇聯 Jupiter-9 85/2 MC (M42) 外拍後，想到應該要與西德 Zeiss-Opton Sonnar 85/2 T (Contax RF) 比較一下，所以就做了這次的測試記錄。我將兩顆鏡頭都裝上了Sony E轉接環，就高度而言，Jupiter-9 約高了1~2mm，縮光圈至 f4 時，Jupiter-9呈現近乎圓形，Zeiss-Opton則是多角星芒狀，重量手感則是差不多。

These test shots were taken indoors under mixed lighting conditions, combining tungsten bulb lighting with daylight coming through a window. Comparing both lenses wide open at f/2, I personally find the Jupiter-9’s background rendering more pleasing, with stronger subject separation and a greater sense of three-dimensionality. The Zeiss-Opton Sonnar, on the other hand, stands out for its superior sharpness and contrast. When stopped down to f/4, it becomes even clearer that the horizontal lines behind the text are actually composed of dotted segments. I’ve also included both full-frame images and enlarged crops for reference.

All test photos below were taken with a Sony A7C with in-body image stabilization enabled (85mm setting).

這次的測試照片是在室內燈泡光源和窗戶室外光源混和的條件下拍攝的，以光圈f2來比較，我覺得 Jupiter-9 對背景虛化的處理比較令人討喜，也較有立體感，而Zeiss-Opton Sonnar 則是勝在銳利度和反差，縮光圈到 f4 時更可以清晰地看到文字後的橫線是點狀虛線所組成。同時附上全幅和放大裁切後的相片給大家參考。

以下測試照片均以 Sony A7C + 防手震啟動(85mm) 拍攝


Jupiter-9 85/2 MC at f2, 1/250, ISO400


Jupiter-9 85/2 MC at f4, 1/60, ISO400


Zeiss-Opton Sonnar 85/2 T at f2, 1/250, ISO400


Zeiss-Opton Sonnar 85/2 T at f4, 1/60, ISO400

Center crop at 100% magnification:

擷取影像中間，100%放大後：


Jupiter-9 85/2 MC at f2, 1/250, ISO400


Jupiter-9 85/2 MC at f4, 1/60, ISO400


Zeiss-Opton Sonnar 85/2 T at f2, 1/250, ISO400


Zeiss-Opton Sonnar 85/2 T at f4, 1/60, ISO400

MC Jupiter-9 85mm f2 and Sony A7C

2026/3/22






My third collectible Soviet lens is the Jupiter-9 85mm f/2 MC, a lens with a strong lineage tracing back to the pre-war Carl Zeiss Jena Sonnar 85mm f/2 made for Contax RF cameras. This particular copy was manufactured in the late 1980s and features MC multi-coating. Although the exterior shows heavy signs of wear, the optics themselves are actually quite clean. When I first received the lens, the aperture scale and index mark did not line up correctly. I spent quite a bit of time disassembling the entire optical block and aperture ring, then recalibrated and reassembled it so that each aperture marking now aligns perfectly with the indicator.

The most distinctive characteristic of this lens is its rendering wide open: contrast is very low and the image appears soft and dreamy, but once stopped down, the contrast improves significantly. In the first photo, the background blur behind the uBike bicycle seems to “melt away” into the distance, while the highlights carry a slightly creamy texture with a hint of swirl, producing an exceptionally smooth bokeh.

我收藏的第三顆蘇聯鏡頭是Jupiter-9 85mm f2 MC，與戰前的CONTAC RF相機接環的Carl Zeiss Jena Sonnar 85mm f2有著濃濃的血緣關係。這顆鏡頭是上個世紀80年代後期製造的，有冠上MC鍍膜，雖然外觀磨損的很厲害，鏡片倒是蠻乾淨的。這顆鏡頭剛到手時，光圈環的數字和指標位置有些差異，我費了一些功夫拆下整個鏡組和光圈環，將光圈環重新鎖定在正確的位置，讓每個光圈環的數字和指標都能對得上。

這鏡頭最大的特色是在光圈全開時，反差很低、很柔和，但縮光圈後反差也就好很多。第一張照片uBike腳踏車背後，散景一路往後「化開」，高光邊緣帶一點奶油感與旋轉感，非常滑順。