香港老餅家

雖然中大幅人數在老餅家不算很多，但有不少精通中大幅之士。
希望可以集中討論，幫助中大幅新丁! (當然包括我) 謝謝!


F22思迷?
有名中大幅風景相，大部份都是用F22光圈或者更細光圈F64。除了景深因素外，每支鏡最高效率是F22光圈? 另外連每支鏡的IMAGE CIRCLE都是以F22來算，是不是F22能給到最大IMAGE CIRCLE，而F5.6給不到? 那F5.6光圈除了方便對焦外，實用價值在那裹??


老超是不是有支Caltar 210MM F5.6鏡?

你 才查 左 幾多件？

cco 寫:F22思迷?
有名中大幅風景相，大部份都是用F22光圈或者更細光圈F64。除了景深因素外，每支鏡最高效率是F22光圈? 另外連每支鏡的IMAGE CIRCLE都是以F22來算，是不是F22能給到最大IMAGE CIRCLE，而F5.6給不到? 那F5.6光圈除了方便對焦外，實用價值在那裹??

>>> 每支鏡最高效率是F22光圈?
Almost!

>>> 另外連每支鏡的IMAGE CIRCLE都是以F22來算，是不是F22能給到最大IMAGE CIRCLE，而F5.6給不到?
F22以後既光圈既image circle, 會再大D, 但分別不大!
F5.6既image circle細D! (但都可用黎影相!)

>>> 那F5.6光圈除了方便對焦外，實用價值在那裹??
影大光圈, 淺景深既相! (e.g. Portrait, Fashion)

I don't have any Caltar. Mine are Schneider, Rodenstock and Fujinon.
Why use F22? It is because my lens are small in aperture and they are not very good performance in wide open. But in fact, some of my lens already perform better in f/16 or f/11 when compare to F/22.
The image circle of Schneider is calculated at F/22, but Rodenstock using F/16. The larger the aperture, the larger the image circle. But, the larger the aperture, the more spherical distortion there, which means that even you can record on film, it is a blur image only.
Believe it or not, Super Symmar HM already owning nearly 90% top performance at there aperture wide openned.
This is also true to most ED/APO class tele lenses.

mmm...

可否解釋下...
image circle? 影像圈? 是景深引起的圈圈?

Schneider is calculated at F/22, but Rodenstock using F/16?
是設計時用F/22 和 F/16 為標準?

the larger the aperture, the more spherical distortion there?
大光圈 有更多 鏡光變型問題?


thx... 各老前輩...

NetNetBoy 寫:mmm...

可否解釋下...
image circle? 影像圈? 是景深引起的圈圈?

It has many different name, e.g. coverage, covering power, circle of acceptance
of definition ... (just recall from my memory, maybe a bit different)
>>> 是景深引起的圈圈?
No, I think you mixed up with the term "circle of confusion".

NetNetBoy 寫:Schneider is calculated at F/22, but Rodenstock using F/16?
是設計時用F/22 和 F/16 為標準?

Different lenses have its different standards.

NetNetBoy 寫:the larger the aperture, the more spherical distortion there?
大光圈 有更多 鏡光變型問題?

Shortly, larger aperture, smaller covering power.

Cloudy 寫:

cco 寫:F22思迷?
有名中大幅風景相，大部份都是用F22光圈或者更細光圈F64。除了景深因素外，每支鏡最高效率是F22光圈? 另外連每支鏡的IMAGE CIRCLE都是以F22來算，是不是F22能給到最大IMAGE CIRCLE，而F5.6給不到? 那F5.6光圈除了方便對焦外，實用價值在那裹??

>>> 每支鏡最高效率是F22光圈?
Almost!

>>> 另外連每支鏡的IMAGE CIRCLE都是以F22來算，是不是F22能給到最大IMAGE CIRCLE，而F5.6給不到?
F22以後既光圈既image circle, 會再大D, 但分別不大!
F5.6既image circle細D! (但都可用黎影相!)

>>> 那F5.6光圈除了方便對焦外，實用價值在那裹??
影大光圈, 淺景深既相! (e.g. Portrait, Fashion)

THANK!

如果不同光圈有不同的IMAGE CIRCLE，我想知道不同光圈的IMAGE CIRCLE，可不可以計算出來。(因為不同的IMAGE CIRCLE會影響到鏡的TILT,
RISE, SHIFT等.)

題外話，為何鏡廠只多數只LISTF22/F16光圈的IMAGE CIRCLE，而不會全部LIST出來？

香港至NET超人 寫:I don't have any Caltar. Mine are Schneider, Rodenstock and Fujinon.
Why use F22? It is because my lens are small in aperture and they are not very good performance in wide open. But in fact, some of my lens already perform better in f/16 or f/11 when compare to F/22.
The image circle of Schneider is calculated at F/22, but Rodenstock using F/16. The larger the aperture, the larger the image circle. But, the larger the aperture, the more spherical distortion there, which means that even you can record on film, it is a blur image only.
Believe it or not, Super Symmar HM already owning nearly 90% top performance at there aperture wide openned.
This is also true to most ED/APO class tele lenses.

thank

想問清楚, 光圈越大,image circle越大,還是光圈越小,image circle越大???

另外，在大過f/22/f16的光圈時,會不會好以135鏡會有洐射,而影響最後成像。

老超, 可能我看錯。
Schneider 和Rodenstock 都有為CALUMET Caltar 出鏡，請問CALUMET Caltar 的鏡是不是等同原廠，或者好以sinar,linhof等要求高過原廠。

對Super Symmar HM , ED/APO class tele lenses的分別有興趣，遲些再talk.

Cloudy 寫:

NetNetBoy 寫:mmm...

可否解釋下...
image circle? 影像圈? 是景深引起的圈圈?

It has many different name, e.g. coverage, covering power, circle of acceptance
of definition ... (just recall from my memory, maybe a bit different)
>>> 是景深引起的圈圈?
No, I think you mixed up with the term "circle of confusion".

NetNetBoy 寫:Schneider is calculated at F/22, but Rodenstock using F/16?
是設計時用F/22 和 F/16 為標準?

Different lenses have its different standards.

NetNetBoy 寫:the larger the aperture, the more spherical distortion there?
大光圈 有更多 鏡光變型問題?

Shortly, larger aperture, smaller covering power.

大幅 image circle ,視角xx度，景深的關係有小小混亂, 可不可以講楚小小.
謝謝

kiev 寫:你 才查 左 幾多件？

無需過敏，只是做多些功課先。

另外，知不知深圳附近有比較多攝影書(講45)賣,深圳書城? 想找些鬼佬攝影書的中文版.

cco 寫:如果不同光圈有不同的IMAGE CIRCLE，我想知道不同光圈的IMAGE CIRCLE，可不可以計算出來。(因為不同的IMAGE CIRCLE會影響到鏡的TILT,
RISE, SHIFT等.)

唔知間廠係計出黎定 "度" 出黎喎, 我估係 "度".

cco 寫:題外話，為何鏡廠只多數只LISTF22/F16光圈的IMAGE CIRCLE，而不會全部LIST出來？

有無咁既需要!

cco 寫:想問清楚, 光圈越大,image circle越大,還是光圈越小,image circle越大???

Image Circle = Coverage, 所以, 光圈越大, image circle越細, vise versa.
我諗超人係手快快, 打錯字嗟.

cco 寫:另外，在大過f/22/f16的光圈時,會不會好以135鏡會有洐射,而影響最後成像。

有, Diffraction (繞射) 係光學現像, 只要係細光圈, 唔理乜野鏡, 繞射就會特別明顯.

cco 寫:大幅 image circle ,視角xx度，景深的關係有小小混亂, 可不可以講楚小小.
謝謝

基本上, Image Circle (coverage, 中文唔識) 同景深無乜關係, Image Circle既意思係話, 呢個圈既範圍
以內既解像力係可以接受, 所以我曾經見過有書/catalouge叫佢做Acceptance of Definition (大概名稱).

至於景深, 係同另一個圈, 模糊圈 (Circle of Confusion) 有關, 由模糊圈而引申Depth-Of-Focus (焦深), 再由
Depth-Of-Focus而引申Depth-Of-Field (景深).

cco 寫:另外，知不知深圳附近有比較多攝影書(講45)賣,深圳書城? 想找些鬼佬攝影書的中文版.

書城有一兩個專櫃，樂凱(賣器材那間)亦有！柯凸果本大畫幅攝影，廣州果間"黑白"專門店亦有。

kiev 寫:

cco 寫:另外，知不知深圳附近有比較多攝影書(講45)賣,深圳書城? 想找些鬼佬攝影書的中文版.

書城有一兩個專櫃，樂凱(賣器材那間)亦有！柯凸果本大畫幅攝影，廣州果間"黑白"專門店亦有。

THANK

你對深圳那麼了解, 不如搞返個深圳一日攝影團，去買下書和"吸毒"

另外，有沒教4x5機的書介紹。