CONTAX CLUB Carl Zeiss 討論區

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文章發表於 : 週三 08 10月 08 22:57:33 
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How do you check the len being disassembled?


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文章發表於 : 週三 08 10月 08 23:09:37 
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註冊時間: 週一 01 12月 03 00:25:39
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最緊要係睇鑼絲位, 開過既鏡 D 鑼絲唔多唔少都會有明顯受損痕跡
其次係睇下支鏡既光圈, 有 d 組合得唔好, 光圈收細時會有 d 移位 (唔係整過都可能跌過)


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文章發表於 : 週三 08 10月 08 23:38:28 
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註冊時間: 週日 09 11月 03 03:42:29
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Qoo牛 寫:
vincenthoy28 寫:
Qoo牛 寫:
vincenthoy28 寫:
Qoo牛 brother, just share some of my experience
1. 180 MMG vs MMJ - MMG deliver much higher image resolution especially enlarge it over 15R. The MMJ deliver much more soft tone and give a "paint" feel.

2. 100/2 MMG vs MMJ - The MMJ deliver much sharper and more 3D image and MMG seem a bit disappoint me..

3. 85/1.4 MMG vs MMJ - MMG version delivery more vivid color then MMJ.

4. 35/1.4 MMG vs MMJ - the different is really not much at all...


Hi Vincentoy28 brother
you did those test with same situation, tripod and some roll of slide?

not slide..but neg film...same roll of film, same printing setting same camera setting.


Dear Vincentoy28 brother
neg film d 色永遠都唔準, 就算你同鋪頭講直出, 其實都唔係直出

However, if same roll of film, same setting of printing, at least I will say the "different" will not be too much...

nevertheless, just my own experience....

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文章發表於 : 週四 09 10月 08 01:11:33 
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註冊時間: 週一 01 12月 03 00:25:39
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Dear vincenthoy28 兄
其實同時推有相同焦段的 G 同 J 鏡的人己經不多
可況再加上做對比的, 實在難得
非常感謝你的分享 :D


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文章發表於 : 週五 10 10月 08 19:51:35 
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註冊時間: 週二 05 4月 05 10:39:50
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I do think J and G are similar in performance and I did comparing the J and G. But it is better to have some lenses from Germany since they are rare comparing to Japan-made in general.

The glasses of some old lens turn yellowish mainly due to the glass itself not the coating. Long time ago manufacturers added some rare earth metals into the glasses (patented by Kodak and invented by Zeiss Jena) and to enhance their performance. They mostly were radioactive and oxidized along with time. Once they oxidized the glasses turned a bit yellow. Try to find some old aerial lenses from Kodak and they are radioactive (you may need to wear lead underwear : ) when you use them) and they all turn yellowish.

And in late 1980, moulding synthetic glasses were coming to the market and they are very easily turn yellow. Even today, some oem branded synthetic spectacle glass will turn yellowish very fast.

Zeiss was still using Leaded glass till 1980. You may find that the Zeiss 135/2 is a five elements lens and no other manufacturer can make this lens with 5-element nowadays. An article (you may find on the web) mentioned that the good designed old lens from 1960 has equal or similar performance in resolution with modern lens and it was because they were using heavy-metal glass.

The oldest Zeiss I have is 1980 made and it still in very good condition without turning yellow. I have no data if Zeiss use radioactive or rare-earth metal in their glass which will turn yellowish. But very sure that all lenses I have has no "yellowish" problem and most of them are AEG. I do love AEG since they are more "classic" when compare to MMG : ).......pyscologically.

35/1.4 aeg is better and if you have rollei 35/1.4 is much better and they are machine polished and not moulded glass of its aspherical element.

Zeiss stop manufactured some lenses after using non-leaded lens may be due to the fact that they can't stick to the original lens formular. However, the new technologies are slowly taking the advantages and makes better lens nowadays.

So, it's all depend which lenses you are collecting.
I prefer 85/1.4 aeg mmg 35/1.4 aeg late version of 18mm aeg, 24 aeg and 100/2 aeg

Some lenses are only made in Germany such as 70-210mm 3.5 (now I have three). 135/2, 16mm and 28mm/2

Get them all if you can since it is better than stock nowadays : )


Leo


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文章發表於 : 週二 14 10月 08 16:17:56 
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leojar 寫:
I do think J and G are similar in performance and I did comparing the J and G. But it is better to have some lenses from Germany since they are rare comparing to Japan-made in general.


I agree with you

引言回覆:
The glasses of some old lens turn yellowish mainly due to the glass itself not the coating. Long time ago manufacturers added some rare earth metals into the glasses (patented by Kodak and invented by Zeiss Jena) and to enhance their performance. They mostly were radioactive and oxidized along with time. Once they oxidized the glasses turned a bit yellow. Try to find some old aerial lenses from Kodak and they are radioactive (you may need to wear lead underwear : ) when you use them) and they all turn yellowish.


I'm fully understand this, yellowish is not due to the coating.
what I mean is old glass is easy to turn yellowish
and also newer design has better coating technique for light reflection

引言回覆:
And in late 1980, moulding synthetic glasses were coming to the market and they are very easily turn yellow. Even today, some oem branded synthetic spectacle glass will turn yellowish very fast.

Zeiss was still using Leaded glass till 1980. You may find that the Zeiss 135/2 is a five elements lens and no other manufacturer can make this lens with 5-element nowadays. An article (you may find on the web) mentioned that the good designed old lens from 1960 has equal or similar performance in resolution with modern lens and it was because they were using heavy-metal glass.


thats truth

引言回覆:
The oldest Zeiss I have is 1980 made and it still in very good condition without turning yellow. I have no data if Zeiss use radioactive or rare-earth metal in their glass which will turn yellowish. But very sure that all lenses I have has no "yellowish" problem and most of them are AEG. I do love AEG since they are more "classic" when compare to MMG : ).......pyscologically.


引言回覆:
35/1.4 aeg is better and if you have rollei 35/1.4 is much better and they are machine polished and not moulded glass of its aspherical element.


I hear this from internet too but there are some questions, any official document has mention about this? I never found any information that about the german version is machine polished and japan version is moulded glass from official.
but I found those people talking about this even dont know which glass is the aspherical lens of D35/1.4!

leojar, you know very depth about the zeiss lens history
very happy to discuss with you : )


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文章發表於 : 週二 14 10月 08 17:07:57 
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註冊時間: 週六 08 11月 03 07:56:21
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leojar 寫:
引言回覆:
35/1.4 aeg is better and if you have rollei 35/1.4 is much better and they are machine polished and not moulded glass of its aspherical element.


I hear this from internet too but there are some questions, any official document has mention about this? I never found any information that about the german version is machine polished and japan version is moulded glass from official.
but I found those people talking about this even dont know which glass is the aspherical lens of D35/1.4!


I should have posted this link long long time ago. A good reference from a Japanese webpage which mentioned about the change on manufacturing method of the aspherical surface of Distagon 35/1.4 (as in paragraph 2):

http://www.asahi-net.or.jp/~eg3y-ssk/ph ... 2j/g2j.htm

Although there is no official announcement / evidence either, he (the webmaster had appeared in an interview of a Japanese magazine which was dedicated for CONTAX cameras, so I know he should be "he") do stated an interesting point. That is, comparing the price of CONTAX lenses in the 80's and year 2000, most of the Made in Germany lenses do have a huge raise over the years, e.g

Distagon 15/3.5 from 306500 yen (1983) to 700000 yen (2000)

PC-Distagon 35/2.8 from 196000 yen (1983) to 390000 yen (2000)

F-Distagon 16/2.8 from 180000 yen (1983) to 475000 yen (2000)

And for the Planar 100/2, AEG version was priced at 141000 yen during 1981, while MMJ version was to be 178000 yen at 2000. So generally most CONTAX lenses do have an inflated price over the years.........except for Distagon 35/1.4 in which:

Price in 1983 = 182000 yen

Price in 2000 = 168000 yen

And this should be the only lens which encounter a price reduction over the years.......

The webmaster also quoted example for Sonnar 85/2.8, for which:

Price of AEG = 82000 yen

Price of AEJ = 55000 yen

Price of MMG = 75000 yen

He also mentioned about the lens weight issue, but no actual data had been quoted and too bad 極樂堂 had closed the page on weight comparison for different version of D35/1.4:

http://contax1.hp.infoseek.co.jp/weight/

----------------------------------------------------------------------------------------------------------------------

We may cross check the prices he quoted from the homepage of 極樂堂 (in which the price of the year he quoted may not be exactly correct, but the trend of the price he mentioned should be 100% correct)

Let us check the price of 1989 and 1990:

Distagon 35/1.4 AEG (1989) - 178000 yen
Distagon 35/1.4 MMG (1989) - 187000 yen
Distagon 35/1.4 MMJ (1990) - 168000 yen

http://zeiss.hp.infoseek.co.jp/yc-lens.htm

-----------------------------------------------------------------------------------------------------------------------------

A bit off topic if one would like to learn a bit more on Distagon 35/1.4...................

Another Italian webpage discuss about the origin of the Ditstagon 35/1.4 (Should be close relatives of Distagon 35/1.2 of Arriflex)

http://www.luciolepri.it/lc2/marcocavin ... 00_pag.htm

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文章發表於 : 週二 14 10月 08 17:31:32 
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Hi Wah

I've read this site long time ago too
but anyone can tell what is the different between machine polished and molded glass?
dosent mold glass should more accurate than man polish?


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文章發表於 : 週二 14 10月 08 17:49:30 
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Qoo牛 寫:
Hi Wah

I've read this site long time ago too
but anyone can tell what is the different between machine polished and molded glass?
dosent mold glass should more accurate than man polish?


For sure we cannot tell hand / machine polished aspherical elements must be superior to molded glass. I suppose even if we make an equiry to Carl Zeiss (and if they do admit there had been such a change in manufacturing process) the official answer must be no difference at all! But I would think the hand / machine polished method must be of higher cost for large production run.

However, as the case in Leica M Summilux 35/1.4 Aspherical VS Summilux 35/1.4 ASPH, the ASPH one (with 1 surface of molded aspherical) do have inferior MTF performance than the Aspherical one (with 2 surfaces of hand-machined asphercial) at f/1.4 wide open ( I only have hardcopy of MTF graph on hand, will try to find online version later). On the other hand, you may find comments from Leica fan club forum or other online forum, in which owners of Summilux 35/1.4 Aspherical do find variation in performance of different samples of the lens. This may be a signal that hand-machined production method may not be good at maintaining a constant quality..........

Erwin Puts on Noctilux 50/1.2 regarding difficulties for hand-made aspherical surface:

http://www.imx.nl/photo/leica/lenses/lenses/page55.html

It is true that hobbyist do always in favour of kind of features which "sounds" to be superior / marvelous, though it may not be such on technical terms..........

Somehow this should resemble the argument of Quatz VS Mechanical watches! :o

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文章發表於 : 週二 14 10月 08 20:34:34 
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註冊時間: 週二 05 4月 05 10:39:50
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Before Zeiss moved the production from Germany to Japan, Cost of manufacturing is one of its headache. Zeiss can't figure out why Japanese can make a great lens with lower cost. Zeiss, at that time, still only have NC controlled grinding machine in its mass production line. However, moulding technology is best suit to mass market even though the startup cost is high. Once zeiss pass the design to Japan, Japanese company always think big (consumer market) and develop a really great glass moulding technology which can produce the inferior quality aspherical elements. Even today, the only limited edition or expensive (aka small quatity) lenses are produced in Germany. I believe Zeiss Germany still grinding the aspherical elements but not moulding them. It is the cost issue rather than the quality issue. Grinding aspherical elements is cheaper than moulding if in small batch production.

To be collector of zeiss lens, machine grinding lenses are better since they are lesser in the market and older (antique) and yes they are not the same from lens to lens. It means they have their own characters like human.... : )

Just know a bit but not much. I do believe most of the stories we heard are the prediction or guessing. No one can prove it except the production team in zeiss. it is more interesting to be like that.

Leo



Leo


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文章發表於 : 週四 16 10月 08 07:29:00 
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註冊時間: 週五 28 11月 03 23:54:34
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呢個FAQ是否需要修改?

http://www.zeiss.com/C12567A8003B58B9/C ... 04AD17F#04

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文章發表於 : 週日 19 10月 08 15:04:14 
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註冊時間: 週日 28 11月 04 23:49:48
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Terry Sham 寫:


From my casual comparison I think the answer yes. Strictly speaking maybe not. As long as differences are within engineering/manufacturing tolerances, two things are considered the 'same'. The results below, however, are different enough to be visible, even if they all fall within Kyocera&CZ quality check & tolerance.

Below are 2 sets of comparisons. Unfortunately I did it during a cloudy day before I sold off the AEG the next day (reason being lens condition after careful examination with a torch light). 1st set the flower taken with AEG appears soft. 2nd set with the AEG, the reflective surface of the fruit is rendered much better than the MMJ version. All taken with tripod and the lenses were supported by Manfrotto #293 telephoto lens support.

MMJ version Sonnar 180mmm @f2.8; AEG version @f2.8
圖檔圖檔

MMJ version Sonnar 180mmm (maybe @f4); AEG version (same f). Focus is on the fruit on the lower left quadrant.
圖檔
圖檔[/img]


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