>>LIGHT PLACEMENT
>> ISO 640, 45mm, f/4.5, 1/250 sec.
In this photograph, a soft box was used to soften the shadows on the subject's face. But at the same time I used a speedlight from little bit far away so the shadows created by it is not so harsh; and I could make the background invisible (particulary right side) to enhance the contrast.
In this case the two light sources were placed like this:
>> PLACEMENT A
I could not find her dominant eye; yet if I light up the right side of her face, her hair on the right side may cast some shadows on the upper-right side of her face: So I have decided to light up from left side.
I had to move around a soft box for a few times to see the difference and choose the best picture with a visible key-triangle.
>> ISO 640, 45mm, f/4.5, 1/100 sec.
>> PLACEMENT B
In this photograph, a soft box was used again to soften the shadows on the subject's face. But I did not use the speedlight (so the shutter speed is slower), so the shadows on the right side of her face is more softer and the highlights are warmer, compared to the Placement A.
In this case a soft box was placed like this:
I have decided to light up the left side of her face because of the same reason with Placement A.
When I looked up on the internet, I found that the key triangle appears not only in the position like Placement A; I have decided to shoot at a different angle from Placement A. I had to move around a soft box for a few times to see the difference and chosen the best picture with a visible key-triangle.
In this experiment, I learned that the finding of key-triangle is very important when judging whether the lighting for this particular type of portrait is proper or not. I've also noticed and learned that the key-triangle appears not only when the angle of a subject is like that of Placement A, and the fact that there often are a side of which I should light up; In this case, the hair. By considering the dominant eye or where the subject's hair is parted, I will be able to predict the state of how the highlights and shadows appear perhaps without lighting up each side and checking the difference.