[siutang]

最初由 阿瓜 发布
You may find a monopod is more useful when shooting actions (include birds).

you are absolutely right 瓜兄，I just bought my monopod two weeks ago, hehe

[siutang]

最初由 Xterra 发布
I heard, and also what I have experienced with my own lenses, that for any lenses, stopped down 2 full apertures, would give you the sharpest image a lens capable to produce. Say, my Canon F/4L lenses, when stopped down to around F6 the images start to get sharper. Also from many Lenses review websites, I heard, for most lenses, F6-F11 produce the sharpest images. F8 normally the sharppest point. you get the image. When photoing fast moving objects, aka flying birds, a sunny day is really needed. this way, you can reduce F down to say, F8, increase the shutter speed to 1/1250 or faster, while you are still able to get enough light into your lens to produce a sharp image.

above is what I have heard and also matches my own experience. Hope it can be helpful.

thank you Xterra, I've heard of that too, but since it was sort of dark there, it's hard go get a shot at F8 without a tripod >_<

[siutang]

最初由 startrack 发布
"that for any lenses, stopped down 2 full apertures, would give you the sharpest image a lens capable to produce"
这句话是针对当时的镜头研磨及镀膜技术来讲的，当时（上世纪60-70年代）的镜头都是基于3。5-4的光圈来讲的，特别是变焦镜头，于是就有了f8最佳中心/边缘像质的说法。
另外，f4-f5.6-f8,而不是f4收两档是f6,是根号2的关系。

在startrack兄身上?能?到好?西

[Xterra]

最初由 startrack 发布
"that for any lenses, stopped down 2 full apertures, would give you the sharpest image a lens capable to produce"
这句话是针对当时的镜头研磨及镀膜技术来讲的，当时（上世纪60-70年代）的镜头都是基于3。5-4的光圈来讲的，特别是变焦镜头，于是就有了f8最佳中心/边缘像质的说法。
另外，f4-f5.6-f8,而不是f4收两档是f6,是根号2的关系。

I don't know about others. I don't get softer images at F4 on both of my lenses, period. under the same conditions, I do get a sharper image starting F6 all way down to F11. May be my lenses made by old technology?

Hmmm.... I don't think you understood my post. did I say F6 is 2 stops down from F4? I am welcome any corrections, but please make sure it was wrong first?