[man1492]

一架時速100KM既車.要用幾多份一快門,先可完全固定影像呢?

depends on focal length

又再問.2000/1秒快門.可以影幾快既物體呢??有無一條公式呀?

depends on focal length

咁最後問.4000/1和8000/1秒快門.是否人眼已經追唔上呢?

depends on speed of object.

[怪俠]

我唔係數學專家，可唔可以講小小野？
你頭兩條問題是要講埋相機同被攝物ge距離架。

人眼好水皮，幾十分之一秒已經追唔上...

[nfever]

這可能不是數學題, 應該是生物題才對

[彼德班]

樓主o既數學根基真係有 d 問題喎 .......

我估你係想話 1/2000 秒、1/4000 秒、1/8000 秒 !

如果 2000/1 秒 = 33.3333.... 分鐘
如果 4000/1 秒 = 66.6666 .... 分鐘
如果 8000/1 秒 = 2.22222 .... 小時

[怪俠]

你知人講乜又要叉能廚人.............

[man1492]

Simple think of how long the target stays visible within the viewfinder you will know the answer (how long the target travels in pixel/time to be more precise)

[彼德班]

我估o架咋 .............

係喎，我唔係數學專家，唔應該「進」o黎，sorry，打搞晒 !

[galleo]

"你知人講乜又要叉能廚人............. "

hahahahha~~~ 唔知點解我總係覺得呢一句係粗口黎... = )

[maximilianyuen]

hahahahha~~~ 唔知點解我總係覺得呢一句係粗口黎... = )

你又要叉能廚人?

ps:
human eyes visual image update to ur brain every 0.3 sec

[tam_dominic]

It all depends on object distance.

eg
a.
I can shot the moon at 1 second with sharp image.
How fast is the moon running in front of our eyes (ie running round our earth) ?

b.
I cannot take a sharp macro shot below 1/60 second because of my unsteady hand. How fast is my unsteady hand moved when I press the shutter ?

I'm not good at mathematics.
Excuse me for mis-entering ;-^)

Happy shooting !

[怪俠]

剛剛在"DC家"睇到有人評別人用搖鏡拍的快艇模型飛馳相唔夠Sharp，快門唔夠快。然後貼一D噴射機升降的相作比較。

嘩！隻噴射機清到丫..............直情成隻吊係空中一樣........

但係我就覺得好怪喇！搖鏡都要清？搖鏡要用超高快門？
現在的人對高清要求好得意，一味要Sharp，Sharp就係一切。

但係我仲未想自已高清上腦！

[kingkonghk]

影轉緊o既萬5轉harddisk, 用1/8000影內圈可能凝結到, 外圈就難d

你可以試下唔同快門影屋企個抽氣, 睇下有乜分別?

[New Order]

Interesting question!
The sharpness of the picture having a moving object will be defined by the relative displacement of the object in the picture.
For 100Km/h moving object, the speed is 27.7m per second (100x1000m per 3600second = 27.7m/s), a shutter speed of 1/27.7s by a steady camera will take a picture where the object having 1m displacement.
If we double the shutter speed to 1/55.4s the picture will have an object under 0.5m displacement.
If we increase ten times the shutter speed to 1/277s, the picture will have an object under 0.1m displacement.
If we increase hundred times the shutter speed to 1/2770s, the picture will have an object under 0.01m displacement. For which the image will be quite sharp if it is a distance shot instead of close-up shot.

[怪俠]

咁無你呢個7頭腦又邊諗得出呢D咁刁鑽ge問題呢？

[kingkonghk]

7下7下咁又話解左個謎, 你下次問D問題唔好咁7就好呀