[winnwong]

朋友問了這個問題, 因小妹技疏, 想請教大家.
我朋友係新手, 唔知應買邊枝好, 佢用d7k的.

[howardshum]

緊係SB900啦, 因小弟用緊SB700跟D90, 有時發現部分效果有小小問題...

[小小生]

一分錢一分貨

[CindyLok926]

新手用SB700可能己經摸不著頭腦，何況SB900？

基本上新手比較適合用SB400，可是可能很快便要升級了，還是用SB700比較好

[mmclub]

Win姐，区别主要是指数，照明既焦段，最重要是一个有PC同电源接口，一个无，专业同业余既区别，仲有就是重量，女仔用，700啦

[HKGB]

如果你的用途是拍一般生活相，SB700可以滿足你的要求，而且這兩支閃燈體積細小，重量又輕，方便攜帶，事實上SB700的火力不太細。

當然，你的主要用途是專業攝影，要在大面積的飛燈，那麼SB900係不二之選。因為這兩支燈的火力真的十分強勁。(註︰但火力強勁亦有唔好處，因為在一般環境下，好少用到咁大火力，用細火力的機會其實較高，但SB900最細火力都唔講得笑，所以帶SB900去影生活相，真係有"殺雞用牛刀"的感覺。)

[九龍人]

當你要搞柔光既時候就會發覺火力仲係大啲好.

[winnwong]

唔知我會否有啲錯誤理解, 900的zoom range 係18-200, 而700的係由24-1xx. 而我朋友用16-85的, 是否也意味著900的合適程度會高啲?

[F4sfever]

aps 16-85 = 24-120 so......
應該 700 實際啲...現在 iso 咁強
guide no. 唔使咁大 la
問題 = d700 好D or D3s 好D.....啫..

[whispermakers]

700落左擴散片好似都cover到18mm.
and than dx x 1.5, 18 x 1.5 =28. 問題應該唔大

[ssannwong]

>>唔知我會否有啲錯誤理解, 900的zoom range 係18-200, 而700的係由24-1xx. 而我朋友用16-85的, 是否也意味著900的合適程度會高啲?

Yes, it is your misunderstanding.

the focal length 18mm-200mm mean the effective flash light covering angle according to your lens focal length. You can see the flashing device move when you change your focal length on your zoom lens. SB-900 can focus the flashlight power to 200mm's angle of view.

The range of the flashlight is based on the Power shown by GN.

[ssannwong]

Big zoom range on flash light will do better in power efficience.

Longer reach of lighting power is based on GN. Good system with TTL can make the flash effect better - that is why people feel Nikon flashlight is better than many other brands.

It is not about its Zoom range, as SB-800 only do 24-105mm. People still like it because of its cost lower with high power equal to SB-900.

[winnwong]

Thx, ssannwong!

So, can I assume a zoom range of 18-200mm will perform more effective than a 24-1XXmm? If my friend uses a lens of 16-85, that means sb 900 will definitely do better since sb 700 is not capable of doing as good as 900 since it does not cover the zoom range from 18 to 23mm?

[howardshum]

仲未訓???

比dsb700既相你睇睇, 不過真係影得好差...

[ssannwong]

>>So, can I assume a zoom range of 18-200mm will perform more effective than a 24-1XXmm?

No~no~no~

The flashlight "zoom" is do by moving the flashing parts forward/backward in the flash light body. By i-TTL the flashlight will know what focal length the lens is, then move the flashing parts in proper position. So the lighting coverage will be "just fit" for your shooting angle if possible (24-120mm for SB-700, 17-200mm for SB-900 -> I know it can do 12mm with 擴散板).

For example, if you use SB-700 with 200mm lens. The SB-700 will move the flashing parts to a position covering 120mm angle of view (20° 20'). But, the 200mm only shooting 12°20′ angle of view. So some light power is wasted beyond the 12°20′ angle of view. However, If the flashlight is powerful enough for the range - that's mean the range within the GN value shown matching with the ISO, the flashlight with only coverage for 120mm will still perform well for 200mm lens.

The "Zoom" of the flashlight is only about power efficience - directly to say is it can help you to save more power. So one charge of batteries can shoot some more photos. It is nothing to do with the flashing quality even to the photo quality.