人像外拍光線淺談 (The Location Portrait lighting in short)

外拍時現場環境的光線是構成畫面亮暗/對比的基礎,環境光線基本上可分成三個部份:1)豔陽強光,2)陰天/多雲/陰影,3)夕陽/華燈初上,如以相機的光圈大小來劃分則可區分如下1)f/16,f/11, 2)f/8,f/5.6,f/4, 3)f/2.8,f/2等,因此在選用打光器材時可依以上所述的三種狀況而定,現在分述如下:

The ambient light is the key element of exposure in the location portrait shooting, the ambient light can be sorted to 3 different aspects: 1) the bright Sun light 2) overcasts/ cloudy sky/ Shade, 3) Sunset/twilight, we can use the camera aperture to describe as: 1) f/16,f/11, 2) f/5.6,f/4, 3) f/2.8,f/2 etc., below is how we can adapt the proper lighting equipment and setting according to the above 3 aspects:

1/160s, (f/10), ISO100, 85mm (EF85mm f/1.2L II USM)

1/800s, (f/2.0), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/10), ISO100, 70mm (EF70-200mm f/2.8L IS USM)

1/200s, (f/10), ISO100, 70mm (EF70-200mm f/2.8L IS USM)

1/200s, (f/10), ISO100, 70mm (EF70-200mm f/2.8L IS USM)

1) 當在豔陽強光時可使用f/16陽光定律(即:光圈:f/16, 快門=ISO),以此定律的組合可應用的設定如快門=ISO=100,200,400,800….等,在此環境光線下光線亮/暗對比大,應選用瞬間發光的專業閃燈才能移除因光線高反差造成的陰影。

2) 在陰天/多雲或陰影環境時,由於環境光線亮度低、亮/暗平均、對比低,因此須放大光圈如f/8,f/5.6,f/4等,同時因光線較為柔和,打光時除閃燈外也可選用如出力(2000燭光(Lux))或以上的恆定光源,如用閃燈可調低出力(如1/8或以下等)的設定並加柔光設備。

3) 夕陽/華燈初上時的環境光線亮度更低,光圈的選定如f/2.8,f/2或更大等,此時適合選用亮度平均、柔和的恆定光源(如2000燭光(Lux))左右或低出力設定的閃燈並加柔光罩,如有須要另加色溫濾鏡以符合環境光線。

1/200s, (f/11), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/11), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/9), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/10), ISO100, 175mm (EF70-200mm f/2.8L IS USM)

根據以上所述的三種環境光線可選擇適當的打光光源如閃燈或恆定燈,一般在強烈環境光線下要使用亮度大的閃燈,而在陰天或多雲狀況下則選擇閃燈或大出力恆定光源(如2000燭光),人像攝影打光的重點在對主體明/暗的雕塑,使二維影像的照片產生符合人類視覺具有景深的立體影像,因此照片陰影部份的產生即是拍攝的重點,現場實務是在環境光中將model安排在適當的位置如背光、側光等,然後依此安置打光設備,如採用補光,打光的技巧是要能延續環境光的光線方向,而非與其相對,重點是要能在拍攝主體上型成陰影產生立體的效果。

1/200s, (f/9), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/16), ISO100, 70mm (EF70-200mm f/2.8L IS USM)

1/200s, (f/16), ISO100, 70mm (EF70-200mm f/2.8L IS USM)

1/200s, (f/18), ISO100, 70mm (EF70-200mm f/2.8L IS USM)

1) The bright Sun light: In the bright Sun shine, normally we follow the f/16 Sunny Law, that is camera setting as aperture: f/16, shutter=ISO=100, except the aperture, the shutter=ISO can be another combination such as 200,400,800…etc., in this ambient scenario, there should be a short interval high power light like flash light, which can balance or overpower the high contrast bright Sun light.

2) Overcast/cloudy/shade: In the overcasts or cloudy scenario the feature of the ambient light is even、darker and low contrast, the lighting equipments can be a continuous light (such as 2000lux or up), if adapt flash light then you can lower the output power (such as 1/8,1/16..) and put on the proper soft lighting devices.

3) Sunset/twilight: During the Sunset or twilight hour, the more darker ambient light needs wide open exposure setting such as f/2.8,f/2..etc., now the soft continuous lighting is more suitable for the darken ambient, if using flash light then lowering the out power even more and a softbox will be needed for balancing the ambient.

1/200s, (f/11), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/9), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/11), ISO100, 85mm (EF85mm f/1.2L II USM)

1/200s, (f/10), ISO100, 175mm (EF70-200mm f/2.8L IS USM)

According to the above 3 ambient scenario we can adapt the proper lighting devices either flash or continuous lights e.g. the bright Sunshine with high power output flash light and in overcasts or cloudy with continuous lights or flash with soft shaping

The essence of lighting in portrait shooting is to produce the light and shadow on the subject, in turn switching the 2 dimension photo to 3D image that matching the human vision, so produce the shadow part in the image is the key point.

On site, we should place the model in the suitable ambient light spots like from side or back etc., and then arrange the lighting equipments to strengthen the light part or fill the dark part and it should be in the direction follow the ambient not against to obtain a nature look.