[ivanivan2]

各位有S85.4的師兄... 小弟以前曾經有過SIGMA 50MM f1.4, 但因為收細光圈焦點有向後移的情況所以放售了... 現在想問一下新的這支85MM有同樣的情況嗎? 因為是新鏡網上資料唔多, 亦唔想茂茂然落鋪叫人開一支俾我試... 所以請各位有SIGMA 85MM 的師兄分享一下... 謝謝!

[frankiecmk]

Just brought last week at DCFever to fit with my Canon 7D.
They only had one Canon mount at shop and tested with their 450D.
Couldn't do much at shop so I take the chance as 7D has Focus adjustment anyway.

Back home, I tested with focus chart and surprisingly, I found the focus was perfectly acurrate.

May be, I'm just lucky.

Start shooting the other day, it's really really good and the color does not seems that warm as other Sigma lens before..

[ivanivan2]

師兄... 謝謝你的回覆... 如果有時間可否測試一下收光圈會有移焦嗎?
例如f1.4, f1.8, f2.0, f2.2, f2.5, f2.8..... 等等各影一張
看看同一個對焦點會否出現景深向後移的情況啊... 謝謝!! ^.^

[frankiecmk]

Yes. ching. I tried all the way from 1.4 to 2.8 step by step and did find back focus after 2.0 or so. But very little, less than 0.5cm And I think this is acceptable for me.

How about yours?

[ivanivan2]

謝謝師兄花時間去試
我以前支S50.4情況都差吾多, f1.4,1.6,1.8都準.. 對焦點在景深的正中間
去到f2.0開始後移都係幾個mm... 再一路收會一路移直至到對焦點在景深最前端會停左... 呢個情況要去到f5先有改善,去到f5對焦點又再次一步步向景深中間行番番去.... -_-"

[ivanivan2]

師兄仲有請問你在DCFEVER買呢家做緊咩價呢? 呢幾日我都可能會落去睇下... 謝謝

[h0001244]

ivanivan2 兄，你講的情況真係幾特別
我在想，對焦一刻支鏡理應係全開的，拍的一刻先會收細至設定光圈，咁點解會有移焦呢？有無研究過點解？

[ivanivan2]

係啦... 最慘佢又吾係走焦喎, 只係用吾同光圈值下個整個景深範圍會向前移, 跟住收到F5開始又向番後... 所以有機身微調都無用...
上網睇過好多網,canon 50.2L, 85.2L同s50.4都有呢個情況
有人話呢個係大光圈鏡頭既死症
但我試過自己支c50.8同埋朋友支c50.4又好準
吾同光圈值下, 但對焦點永遠都係正景深範圍的中間....

其實想買支85mm, 但85L太貴亦有移焦
C85.8紫邊又嫌重... 所以心思思想買S85.4... ^_^

[ICHIBAN923]

其實>>>>>對焦點永遠都係正景深範圍的中間,,,,係唔啱的.
要前一,後三先最正確.

[ICHIBAN923]

表達錯誤.應該
3分1.....即 ___o______

[ivanivan2]

ichiban923 師兄... 不過我測canon d 鏡都好準係正中間(又或者係我無仔細留意), 而sigma 就真係移得好過份... f.2 開始對焦點已經在景深最前端, 直到f5先開始向中間退番番去... 如果影d吾郁既野都仲可以接受, 但我影小朋友, 變咗好易走焦.. 多謝你回覆, 又知多樣野!

[frankiecmk]

Ivan ching. $6300 by credit card. I need to test more on real objects as can't See how the image perform on this circumstance.