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文章發表於 : 週日 21 10月 07 16:14:54 
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註冊時間: 週三 24 5月 06 12:34:40
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好多人﹐用家﹐review 話ZM 點好點好,又話同leica有過之而無不及﹐搞到我都好想買比我的R2M, Leica M4P 試下

但我已有一機三鏡的contax g2, (black version bought for 12k hkd)
當然不免比較一下﹐但發現﹐從zeiss official website 公佈的data, zm lens 輸 contax G 真的不少﹐特別在wide angle 方面﹐ i.e. 21mm, 28mm, 35mm. 後發現﹐zm back element 是比較短﹐聽說是因為zm的design 方向是digital sensor﹐而這個 lens design limitation 當然是負面的. ..........

所以對有contax G2 set, 用M mount film 機的我來說﹐真的很難買下去。


又要講下internet D review 同 leica, Erwin put 的評價我一向不理的﹐ 無證無據﹐無value. 反而我好相信﹐photozone.de, luminous landscape 同埋好/比較老實的zeiss official data.

所以﹐zm 真 是 leica lens 同級的話﹐ 我的G2 set 起不是值﹐無五萬都應該要四萬喇.

有人會說﹐leica 鏡有徠味吾可代替﹐MTF 跟 distortion 不重要, thats another story, that I would never argue.

我想﹐是時候買多set G2。。。


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文章發表於 : 週日 21 10月 07 18:11:02 
討論區會員

註冊時間: 週一 01 12月 03 00:25:39
文章: 179
I have both 21asph, ZM21 and G21
what can I say is
the ZM21's performance is very very similar to 21asph
the only different is, 21asph resolution is little bit higher
ZM21 has the best flare control (nearly no flare!)
21asph and G21's flare is quite scare....
for color tone, ZM21 is little bit warmer than 21asph
for distortion control, G21 is the best
but the weakest point of G21 is the resolution, image is quite soft
about the build quality, leica is best
my ZM21 just came back from japan the fix the barrel problem...
some of my frds facing the same problem before...
although I'm a Zeiss fans
for 21mm lens is range finder world, I will vote for 21asph


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文章發表於 : 週日 21 10月 07 21:55:07 
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註冊時間: 週六 08 11月 03 07:56:21
文章: 5762
資歷老一點的玩家應該尚記得 1994 年 G1 剛推出市面時連三鏡 (28, 45, 90) 索價也要二萬多.......

小弟的 G 系統有G2 + 16, 21, 28, 35, 45, 90, 而 ZM 則有 Zeiss Ikon body, 25/2.8 及 50/1.5

論性能, 個人而言覺得實拍性能兩套系統表現相差不大, 變形方面, 從數據上ZM 鏡的確沒有 G 鏡的好, 不過大家若從 MTF 圖表的分數比較, 1% 變形就是 0.5% 的兩倍, 換轉角度以實拍計, 大家又可容易分別出 1% 與 0.5% 的分別?

作為一個 Carl Zeiss 的愛好者, 看到如此數據當然很不爽..........心裡當然會想為何新產品價錢又貴又好像沒有舊的好?

參考 Carl Zeiss 的 Marketing Manager, Dr. 於 Photo.net 對有關 CFE Distagon 40/4 IF 變形度比舊款差的回應:

http://photo.net/bboard/q-and-a-fetch-msg?msg_id=0066MK

"What do those Zeiss distortion diagrams actually tell us? Let us imagine for a moment there was a lens with a diagram that gave the distortion as minus 5% over the entire field. Would this be a horrible lens with grossly bent lines, bent as ugly as seen with TV-news lenses? Far from it! The images from this lens would be perfectly free from any bending!!! Minus 5% in a Zeiss distortion diagram means that the effective focal length for this point of the image is 5% shorter than the nominal focal length of this lens. So, minus 5% on a graph for a 100 mm lens means, that at this 5% point, the lens would image/position a subject detail like a 95 mm lens would.

In other words: In the Zeiss distortion diagrams the regions of significant bending of straight lines in the image are not the ones characterized by values which are far away from zero, like minus 3 or plus 2, rather, bending occurs in the image where the graph is bent itself.

Now back to the 40 IF vs. FLE comparison: In the 40 IF image there is a region where bending does occur, even more so than in the images from a 40 FLE. But it is far away from the edges of the image which usually act as a reference for straigtness and is therefore less obvious than bending in images taken with the 40 FLE."


那麼為何 ZM 鏡的變形控制沒有 G 鏡的好? 除了是否 symmetrical design 的關係外, Dr. Kornelius J. Fleischer 亦提出另一個 Design parameter - Lens front diameter

"We at Zeiss could have reduced this bending significantly, had we, and Hasselblad, allowed our lens designers to increase the lens front diameter by an inch or so. Hasselblad wanted to maintain the front diameter.............."

以客觀條件比較, G 鏡的普遍 filter size 為 46mm (28, 35, 45 & 90), 而 Biogon 21/2.8 則為 55mm, 相比之下, ZM 的 filter size 為 46mm (21/2.8, 21/4.5, 25/2.8, 28/2.8, 50/1.5) 及 43mm (35/2, 50/2)

為何 ZM 鏡要比 G 鏡設計上小一點? 除了沒有必要預留空間予 AF 驅動部件外, 維持 M 鏡的一貫小巧感覺個人亦覺得是一重要因素

當然, 鏡頭口徑(玻璃直徑) 亦必然是製造成本之一..............

那麼為何 ZM 會比 G 鏡貴上那麼多? 個人覺得有下列幾種原因:

1. ZM 系列的用料確實比 G 鏡好, 要是能把兩系列鏡頭握在手上就能即時感覺到重量上的分別, 小弟由於要進行將 G Biogon 28/2.8 改裝於 Leica Elmarit 28/2.8 三代對焦筒上的工程 , 曾經把一支黑色 Biogon 28/2.8 完全分解.......

以金屬用料計, G 鏡鏡筒的金屬外殼其實頗為單薄, 鏡筒內的部件如 focusing helicoil 則為鋁合金, 用以減低機身 AF 摩打的重量負擔

相反, ZM 鏡作為一支手動對焦鏡頭, 其對焦環, 鏡頭內筒及外筒皆為單一成形金屬製作, 而 focusing helicoil 為了維持對焦環的 damping 及 smoothness 亦採用黃銅 (Brass), 鏡頭的 M 接環用料是 chromed brass, 即使前組的 hood bayonet mount 亦是以 maching 製作, 大家亦需考慮 每個 focal length 獨立的 rangefinder coupling mechanism 同為製作成本之一.........

一支 Cosina Voigtlander 的鏡頭亦比 G 鏡貴, 就是基於這原因

2. Kyocera 乃為日本巨型企業之一, 相比之下 Cosina 的規模頂多只是中小企業 (山寨廠?), Leica Camera AG 亦然, 小弟雖說 G 鏡的用料頗單薄, 不過從其系統設計可見其 R&D 成本一點也不低, 拆開一支 G 鏡後可見其 AF 系統的運作模式, 鏡頭的對焦行程應該與機身的電子測距有一定的 electro-mechanism 作 feedback 等.......加上 G 系列十分高的光學質素, 賣千多二千元的價錢確實是令人驚訝的價錢!

手頭上沒有全部 G 鏡或 ZM 鏡的製造序號資料, 不過從 Hartmut Thiele 的 Fabrikationsbuch Photooptik III, Carl Zeiss Oberkochen 一書中, 當中記錄了於 1997 年前 G 鏡的生產數字, 至當時為止 Biogon 28/2.8 共生產了約 45000 支, Sonnar 90/2.8 亦有約 45000 支, 而於 1996 年推出的 Planar 35/2 亦生產了 50000 支 (此乃到 1997 年的數據, 至 2005 年 CONTAX 停產時相信總產量至少有一倍以上.......), 此生產數字對比 Leica 及 ZM 來說只可以說是天文數字, 總括來說, G 鏡可說是高度工業化的產品, R&D 成本相對為高, 不過能以較平物料及大量生產模式達至低價格, 以高生產技術來達至Good Quality Control. 正如小弟常常覺得, 能夠做出如 Camry, Collora 一類產品的 Toyota 絕對比 Rolls Royce, Ferrari 偉大........... (Maybach 不算........因為 Maybach 像 Arri 鏡 :twisted: )

以 QC 來計, Kyocera 絕對比 Cosina 優勝, 甚至比 Leica 亦然

那麼 G 鏡有何不足之處? 以小弟使用多年的感覺為:

1. 鏡頭設計受制於 AF 系統, 對於如小弟般的 Hard-core 手動對焦 fans 絕對不相信 AF 系統能給予足夠的精準度. 精準度有何重要? 以 G 鏡來說系統並沒有大於 f/2 的鏡頭, 除重量, 鏡 Mount 口徑的因素外, G 的 AF 系統準確度亦是一個問題, 以個人經驗來說, 一支越高性能的鏡頭往往需要越準確的對焦 (這與焦距與光圈問題無關!), G 系列中鏡頭的規格想必是 Kyocera 精心策劃以達至各方面的平衡, 保持價格合理之餘亦避免因景深太淺而引致走焦的情況發生

2. G 系列鏡頭的抗耀光性能 (flare control) 絕對不及 ZM 鏡, 個人經驗如使用 G Biogon 21/2.8 般絕對要小心光班出現的情況, 畢竟兩代鏡頭相距有十年時間, Coating technology 絕對有所分別, 就算 Erwin Puts 亦有提及過 ZM 鏡 flare control 之能力:

http://www.imx.nl/photo/zeiss/the_new_z ... s_3_t.html

ZM 鏡頭以個人的使用感為, 套用日本人的說法為 "畫面安定性較高", 即是以 Flare Control, Tonal Expression, Field Flatness 及 Colour Fidelity 幾方面皆比G 鏡優秀, 傳統 CONTAX 用家會覺得 ZM 系列沒有如 C/Y 或 G 鏡等強烈的色彩感覺, 不過個人覺得 ZM 鏡於色彩層次方面其實比 G 鏡良好, 而因受惠於 Flare Control 及 Field Flatness 的改良下 ZM 鏡的影像亦有較結實及立體感較佳的感覺 (正如 Carl Zeiss 所言是 Arri 鏡的技術轉移? :lol: )

小弟總結: You get what you pay! 絕對不是一分錢一分貨, 因為現實世界往往是一分錢一分貨, 五分錢兩分貨, 十分錢三分貨...............

_________________
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Wah
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www.flickr.com/dicksonlau


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文章發表於 : 週日 21 10月 07 23:45:25 
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註冊時間: 週四 27 11月 03 02:15:48
文章: 3194
來自: Moon Base Alpha
In the end, I think its more a self induced problem more than anything .. to be fair. How much distortion is considered a problem. is it field relevant and most of all, if it actually made it a problem with the actual shooting.

Its IMHO for most of the photographer and especially most on this forum; that such figure do not really made any if even much difference.

And to be frank. Comparing G vs M system is pretty much always a biased one. As they really are not the same kind of photographic tools. Much like SLR is not the same as RF, an AF system vs a MF system is pretty much also hard to be really objective. And one had to go with the fact that its not about just having the system for having the system's sake ( unless you are a collector ) but which suite the need and facilitate the best tool for the need. And for that, onbly the individual photographer can answer to his/her own.

What cannot be denied though is the M system is likely to be carried on for a long time, and the G system is history and will remain a pretty grand and great film setup. Is this setup the right one or the better one, is open to individual opinions.

_________________
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文章發表於 : 週一 22 10月 07 19:54:33 
CONTAX CLUB 會員
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註冊時間: 週六 08 1月 05 22:54:51
文章: 2268
來自: Hong Kong
Whatever the view is, one point I strongly agree is that G system are unreasonablly and significantly under-priced given its impressive quality ... so yes, go and get one more set and you would not regret.

_________________
Contax : RTS, RTSII(50Y), RTSIII, Aria D, Aria(70Y), N1, ND, T3D(70Y), G2D
Nikon : FM3A, FM3AB
Leica : M9, X1
Fuji : X100
OM : EP2


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文章發表於 : 週一 22 10月 07 21:38:33 
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註冊時間: 週三 24 5月 06 12:34:40
文章: 43
thanks for the deep insight and well thought interpretations, you guys makes me mind wide open.

the only current Zeiss lens I own is 50mm 1.4 ZS, comparing it to my other 4 vintage 50mm 1.4 lens, (namely minolta MD, Rollei SL , SMC takurma , CZJ PB ) , they actually have very similar performance , however, once you shoot against the light source, ZS stand out of the crown by a big margin. according to other zm users experience, I believe this the what ZM lines excel as well.


Yet, I can not agree that the sub-optimal performance in resolution and distortion on the new ZM lens is forgivable, although 0.5% and 1% distortion might not be noticeable , but this extra mile in performance is the what the premium price for. otherwise, why not settle with second line manufacturers when they have done a brilliant job especially in recent years. CV for RF and Sigma/tokina for SLR.

sounds like that I really dislike the zm line? actually, it is the opposite, their are beautifully built , and the amazing anti flare abiliy that I experienced from ZS make them very tempting to me. It is just that I am asking too much .

It is time to drop the shopping urge and take better photos.



:D


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文章發表於 : 週六 11 6月 16 20:57:37 
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註冊時間: 週二 07 6月 16 20:15:03
文章: 15
我2樣都有,覺得contax G2 set好用d


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文章發表於 : 週二 01 11月 16 13:46:12 
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註冊時間: 週一 31 10月 16 19:04:32
文章: 10
koppie 寫:
好多人﹐用家﹐review 話ZM 點好點好,又話同leica有過之而無不及﹐搞到我都好想買比我的R2M, Leica M4P 試下

但我已有一機三鏡的contax g2, (black version bought for 12k hkd)
當然不免比較一下﹐但發現﹐從zeiss official website 公佈的data, zm lens 輸 contax G 真的不少﹐特別在wide angle 方面﹐ i.e. 21mm, 28mm, 35mm. 後發現﹐zm back element 是比較短﹐聽說是因為zm的design 方向是digital sensor﹐而這個 lens design limitation 當然是負面的. ..........

所以對有contax G2 set, 用M mount film 機的我來說﹐真的很難買下去。


又要講下internet D review 同 leica, Erwin put 的評價我一向不理的﹐ 無證無據﹐無value. 反而我好相信﹐photozone.de, luminous landscape 同埋好/比較老實的zeiss official data.

所以﹐zm 真 是 leica lens 同級的話﹐ 我的G2 set 起不是值﹐無五萬都應該要四萬喇.

有人會說﹐leica 鏡有徠味吾可代替﹐MTF 跟 distortion 不重要, thats another story, that I would never argue.

我想﹐是時候買多set G2。。。


感謝分享


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文章發表於 : 週五 28 7月 17 18:37:06 
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註冊時間: 週日 08 11月 09 13:14:21
文章: 77
Interesting sharing. Thank you all.


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