人像棚拍光線淺談 (The Studio Portrait lighting in short)

由於攝影棚內無自然光打光是以人造光為主,因此打光的原則是排除室內其他光線的影響,

In the studio portrait shooting there are a normally artificial lights, so the main thing to concern is avoiding the ambient light interfere,

1/60s, (f/2.5), ISO500, 85mm (EF85mm f/1.2L II USM)

1/60s, (f/2.5), ISO500, 85mm (EF85mm f/1.2L II USM)

相機的曝光設定基本上是ISO=相機的最低值如(100等)快門=相機的閃燈同步快門如(1/200s等),實際的步驟是選定一小光圈(如f/8或以上)試拍一張應是全黑畫面的影像(即無任何室內光線的存在),可模擬在全黑畫面上打開光圈直到光線出現後察看光圈差別”段數”,一般是2-3段左右,例如相機在f/4或f/2.8時可看到室內光線則適當的光圈應是f/8或以上,人造光源的器材主要是閃燈(亮/暗對比高,光線較強)和恆定燈(亮/暗對比低,光線較弱),以下說明三種使用場合包括閃燈恆定燈閃燈/恆定燈混合時的實務操作:

1/60s, (f/2.8), ISO500, 85mm (EF85mm f/1.2L II USM)

1/60s, (f/2.8), ISO500, 85mm (EF85mm f/1.2L II USM)

 

1) 閃燈使用閃燈為光源時須防範室內光線的干擾, ISO值須選相機的最低值,並選擇小光圈,由於閃燈是瞬間發光的不可見光,因此須使用測光表(Sekonic, L-358)來設定光圈值,若要拍攝有模糊背景的效果而須放大光圈時,須使用有高速閃光(High Speed Sync)功能的閃燈¹,此時相機的快門可提高超過閃燈同步快門如1/500,1/1000…等。

2) 恆定燈恆定光是簡單直接的可見光,拍攝時可立即了解光線的分佈,但光線容易受室內光線的影響,因此拍攝時須將室內所有會干擾的光線關閉,由於恆定光線的特性是平均、明暗對比低,拍攝時要使用具大光圈功能的鏡頭(f/2.8,f/2,f/1.8…),同時要採用有高ISO(無雜訊)功能的相機。

3) 閃燈/恆定燈混用由於閃燈發出的光線強時間短可去除室內光線干擾,因此如和恆定光混合使用時因恆定光屬於室內光即無法呈現,打光設定時應以恆定光為主,即放大光圈,適度提高ISO值,此時為配合恆定光的低亮度,閃燈的出力須降低,另外由於恆定光和閃燈有色溫差異,須在閃燈安裝濾鏡(CTO,CTB)來平衡色溫,作法可使用色溫表(Sekonic, c-500)量測兩者的色溫k值來取得平衡。

1/60s, (f/1.8), ISO500, 85mm (EF85mm f/1.2L II USM)

1/60s, (f/1.8), ISO500, 85mm (EF85mm f/1.2L II USM)

4) 附註:

  1. 使用高速閃光(High Speed Sync)時由於產生的連續脈衝光波會使亮度降低,須將閃燈靠近主體,由於高速閃光消耗較多電能因此可提高相機ISO值來因應。

1/60s, (f/2.8), ISO500, 85mm (EF85mm f/1.2L II USM)

1/60s, (f/1.8), ISO500, 85mm (EF85mm f/1.2L II USM)

so it should be a black screen image by camera setting with lowest ISO such as ISO 100 and camera sync shatter speed such as 1/200s or 1/250s, now the last factor of the exposure triangle is the aperture needed to be decided for a black screen, the aperture should be small such as f/8 or smaller, in practical is to set a trial aperture and from a result black image opening the aperture to 2-3 stops then can see the light is the proper setting, for example, if the ambient light can be seen at f/2.8 or f/4 then f/8 or f/11 can be the proper setting.

The artificial lights in studio normally are flash and continuous light which flash light is bright and high contrast and continuous light is dark and low contrast, now there are 3 scenarios in using artificial lights as the following:

1/60s, (f/2.5), ISO500, 85mm (EF85mm f/1.2L II USM)

1/60s, (f/2.5), ISO500, 85mm (EF85mm f/1.2L II USM)

1) Flash light: to avoid the ambient interference the camera setting should be a low ISO value and small aperture a light meter (like Sekonic, L-358) can be adapted for adjusting lighting power to get the accurate f /stop, in case of wide aperture for a bokeh background effect, then using the High Speed Sync¹ function of the flash to against the camera flash syne speed like 1/500s,1/1000s etc..

2) Continuous light: the continuous light is simple and is a what you see is what you get lighting, but it is also can be affected by the ambient light, so any ambient light should be blocked during shooting, the high end lens with wide aperture (like f/2.8,f/2.0,f/2.8…) is needed for this lighting, furthermore the camera with high ISO capability (low image noise) are recommended.

3) Flash & Continuous light mixed: comparing to the flash light which is more powerful enough to get rid of the ambient, the continuous light ( one of the ambient) then won’t be visible, the lighting set up should be depend on the continuous light, e.g. wide aperture、high ISO when mixed with flash, then the flash power should be lowered to balance the continuous light, furthermore the white balance difference between the continuous light and flash should be adjusted by correcting filter (such as CTO,CTB), a white balance meter (like Sekonic, c-500) is needed for more effective operation.

1/60s, (f/2.5), ISO500, 85mm (EF85mm f/1.2L II USM)

1/60s, (f/1.8), ISO500, 85mm (EF85mm f/1.2L II USM)

4)Remarks:

1. In High Speed Sync mode the flash light should be closer to the subject, because of the high speed lighting pulse reducing the flash output power, and the higher ISO value will be recommended to save the flash power.