wah 寫:
siberil 寫:
wah 寫:
很可惜到現時為止.......Carl Zeiss 的 official homepage (
http://www.zeiss.com/photo) 尚沒有堤供 ZA 的 MTF data.......
至於 Sony 提供的 MTF.............以為自己去o左 Sigma homepage......
咁Sony情況會否同Rollei一樣? 我見佢都好似無CZ既MTF?
Rollei 的問題比較複雜..........長久以來就有 "Made by Rollei" 同 "Carl Zeiss" 之分別, 好像早幾年 Rollei 出的 M-mount 鏡 (Sonnar 40/2.8 及 Planar 80/2.8 ) 或 2.8 GX, FX上的 Planar 80/2.8 都沒有 Carl Zeiss 的 MTF data......
小弟曾經擁有過一支 Rollei SL35 的 Distagon 35/2.8, 七十年代出品但竟然有 803xxxx 的 serial no.! 經 e-mail 查詢 Carl Zeiss 後, 他們表示此鏡的 serial no. 並非屬於 Carl Zeiss 的 production record........
為何 Rollei / Rolleiflex 鏡的 MTF data 不能於 Carl Zeiss homepage 看到?
http://www.zeiss.com/c12567a8003b58b9/C ... f90049667d這一點小弟亦十分費解..........
The lenses mentioned were not produced by Carl Zeiss but by Rollei so no Carl Zeiss MTF were offered. As a Carl Zeiss enthusiast wah must know well all these.
In the first few volumes of CLN, Zeiss explained that they would provide MTF for the lenses they produced if they were so requested by the purchaser of those lenses. Hasselblad and Contax asked for them. That's why we have them in the webpage.
For some unknown reasons, Rollei apparently did not ask for MTFs for the lenses they purchased. Thus we don't have easy access to them. This is true for old lenses as well as modern lenses which Rollei continues to buy from Carl Zeiss, ie their 30mm, 40mm, 50mm, 60mm, 110mm and 120mm for the 6008 series.
As to the ancient MTF graphs of the Rolleiflex TLRs, they should be viewed with caution. The MTF graphs in the old days were done under quite different circumstances to those in the modern times. Now we have the K-8 and K-9 testers, and I was told they are more sensitive to optical defects in the lens. That's why nowadays it's generally more difficult to have a high rated MTF.