[balance01]

我想請教下各位,

1. 一般小型 DC, +EV 或 -EV 時, DC 內? settings 做左?乜? 係唔係改 ISO, aperture, shutter speed 之類?

2. 加一級 或 減一級 (即 +1/3 或 -1/3), settings 係調較左幾多?

[beancurdbean]

1) 變改Shutter speed, aperture, ISO都可以做到+/- EV
2) +/- 1 EV先叫一級, +1EV = 快門慢一倍 or 光圈大一級(除1.4) or ISO大一倍

[balance01]

咁請問,
1. +EV 相片出來會光?定係暗?, noise 會唔會多左?
2. -EV 又如何呢?

[schindlerdennis]

自已拎部機試下+-EV咪知有乜效果!

[tam_dominic]

EV - Exposure Value
+ to increase, - to decrease exposure from the result of the DC metering system.

" 1. 一般小型 DC, +EV 或 -EV 時, DC 內? settings 做左?乜? 係唔係改 ISO, aperture, shutter speed 之類? "
Yes, the adjustment can be done by ISO, aperture or shutter speed depends on the designer of the DC.

" 2. 加一級 或 減一級 (即 +1/3 或 -1/3), settings 係調較左幾多? "
ISO 50, 100, 200, 400, 800
Aperture F2.8, 4, 5.6, 8, 11, 16, 22, etc
Shutter speed 2 seconds, 1 second, 1/2 second, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, 1/250, 1/500, 1/1000 etc
The above are the steps to double the exposure by its own.
eg.
F2.8 - 1EV ==> F4 (the larger the number the less light goes onto sensor)
ISO100 + 1EV ==> ISO 100
Shutter speed 1/500second +1EV ==> 1/250 second

Happy shooting

[Bus Fans]

Exposure compensation:
1. In Manual Mode: no function
2. In Shutter Priority Mode: change in aperture (f value)
3. In Aperture Priority Mode: change in shutter speed
4. In Program Mode: depends on the manufacturer

加一級 或 減一級 (1 stop or 1 step)
+1/3 or -1/3 is "not" 一級, it is 1/3級
The difference between f:1.0, 1.4, 2.0, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64... is 1 stop.
The difference of shutter speed (in sec.) between 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/8000, 1/16000 is 1 stop.
The difference of ISO 25, 50, 100, 200, 400, 800, 1600, 3200, 6400 is 1 stop.

[balance01]

唔該晒上面各位, 但係我仲有個問題, 就係我部全自動機,

當拍室內開閃燈照時, EV=0 時, 出來較黑, 當我+EV 時, 出來更黑, 但 -EV時, 照片出來就夠光.

但當關閃燈時, 反而要加 +EV, 照片出來先會較光, 點解會咁呢? 同閃燈有乜關係呢?

[moleunganthony]

book recommanded

《光與曝光》，伍振榮，2002
it can be found in any (most of ?) HK public library.

[balance01]

d2c,

But, could you explain the strange phenomance of the effects I mentioned below -

當拍室內開閃燈照時, EV=0 時, 出來較黑, 當我+EV 時, 出來更黑, 但 -EV時, 照片出來就夠光.

但當關閃燈時, 反而要加 +EV, 照片出來先會較光, 點解會咁呢? 同閃燈有乜關係呢?

and +EV 相片出來會光?定係暗?, noise 會唔會多左?

thx.

[maximilianyuen]

balance01兄，絕對明白你的問題

我的問題，對不起，有點重複:)
http://www.dcfever.com/forum/read.php?f=1&i=363210&t=363210&phorum_auth=e0b89146fbbddc2f943ffe5c4f417f52

"EV=0 時, 出來較黑, 當我+EV 時, 出來更黑, 但 -EV時, 照片出來就夠光."
相信這只是偶然的…
若我的結論是對的話…
應該所有EV 都一樣-.-(no flash)

[balance01]

>"EV=0 時, 出來較黑, 當我+EV 時, 出來更黑, 但 -EV時, 照片>出來就夠光."
>相信這只是偶然的…


No. I actually repeated many times to draw the conclusion. But please note that the above conclusion is drawn when the flash is ON.

[beancurdbean]

其實 +/-EV 只同測光有關,
+EV會光 (over exposure), -EV會暗 (under exposure)
唔明你因乜會反轉

[balance01]

"其實 +/-EV 只同測光有關"

但自動機的 +/- EV 會唔會 consider 埋 flash?

[kingkonghk]

會唔會自動對焦同點測光問題, 次次個點對唔同位就會咁, 用中央對焦加點測試下, 唔得就用平衡測光, 可能試到

[beancurdbean]

我都試過無端端勁under, 勁over (flash太遠)
就未試過-EV反而光, +EV反而暗.....????