f/2.8 問題 A16 (p2 Post #17 updated with pictures cp)

--EDIT: pls see page 2 #17 and onwards for some comparison.

http://www.flickr.com/photos/lsman/sets/72157607803978288/

其實 f/2.8 用來室外,
IMG_2709
http://www.flickr.com/photos/lsm ... -72157607803978288/
IMG_2710
http://www.flickr.com/photos/lsm ... -72157607803978288/

screen/ monitor 好像可以清晰
但一 close up (100%) 就好 blur..
http://www.flickr.com/photos/lsm ... -72157607803978288/

1.新鏡 + 新手 (f/2.8),所以唔知係唔係自己問題...
2.應該用 f/4 or larger ?
3.張2904
http://www.flickr.com/photos/lsm ... -72157607803978288/
放100%時都 ok... 但DOF 好少...即係個鏡冇問題?

先多謝

[ 本帖最後由 lsman1 於 2008-10-9 21:06 編輯 ]

0

0

愛神

進階會員

Rank: 3 Rank: 3 Rank: 3

2^#

發表於 2008-10-7 11:02 | 只看該作者

原帖由 lsman1 於 2008-10-7 10:56 發表
 http://www.flickr.com/photos/lsman/sets/72157607803978288/

其實 f/2.8 用來室外,
IMG_2709
http://www.flickr.com/photos/lsm ... -72157607803978288/
IMG_2710
http://www.flickr.com/photos ...

我諗室外影用F2.8有地方唔清係因為DOF問題...收細D會好D...如果你用A mode既話就收到shuttle岩岩夠freeze到全部人既動作就最好 (以你post出黎個張為例), 當然你想有特別效果又另計啦..

同埋個最尾個張, DOF 淺係正常架喎...F越大, focal length越長, DOF越淺架麻...

我新手有錯請插

TOP

ahshing

進階會員

Rank: 3 Rank: 3 Rank: 3

3^#

發表於 2008-10-7 11:05 | 只看該作者

其實鏡頭通常收少少光圈就sharp，我有大光圈鏡都唔會成日用盡最大光圈
好似24/2.8，28-70/2.8好多時我都係收到f3.5-4先用，而70-210/4我又會收到f5.6用(如果唔係要佢既散景溶d既話)

TOP

inzite

進階會員

Rank: 3 Rank: 3 Rank: 3

4^#

發表於 2008-10-7 11:12 | 只看該作者

softness at 100% is due to ur lens optic quality at maximum aperture. the dof at f2.8 should be similar to wat u have shown and usually lens performs best in the middle of the zoom range, usually softer at either end of the zoom.

TOP

fresh_banana

進階會員

Rank: 3 Rank: 3 Rank: 3

5^#

發表於 2008-10-7 11:13 | 只看該作者

原帖由 lsman1 於 2008-10-7 10:56 發表
 http://www.flickr.com/photos/lsman/sets/72157607803978288/

其實 f/2.8 用來室外,
IMG_2709
http://www.flickr.com/photos/lsm ... -72157607803978288/
IMG_2710
http://www.flickr.com/photos ...

我用A16 , 係室外(夠光)都係用 F4多, 用2.8真係會淺過頭, 好似 outfo. 咁

TOP

inzite