Light angles can make a big difference to your photography. Using a side glancing light to accent an item with shadows can soften and balance out your image. Hard light is great for that.
What about the face of a young girl wanting to be a model? How would you light her face? A glancing, hard light is going to show every blemish and line in her face. Do you think that she would want that type of photograph in her portfolio? Probably not! By the way, she doesn’t have to be a model. Any woman is not going to like a photo that shows all her acne scars, and other bumps and bulges in her face. Boys and men generally care less than women, but they won’t like seeing every mark and blemish either.
Many model photographers use a hard light source – an on camera flash – but they use a “ring flash” to fill in all the wrinkles and shadows from blemishes.
There are several drawbacks to using a ring flash. First, there are problems from red eye. Second, it creates really odd looking round catch lights in the eyes. And third, since it eliminates shadows, you end up with a flat, 2D image. I recommend against using a ring flash for portrait work. If you need or want a hard light source, use one but put it at an angle to your subject. Then fill in the shadows as needed.
Want to see masterful usage of angles with a hard light source? Pick up any bodybuilding magazine. They use a hard light source glancing across the body to define and visually enhance the muscles.
Consider the angle of your light. A hard light that is off to the side and glancing across the face (or body) will show every muscle, scar, pit and bulge. But move that same light so that it is shining directly into the model – from the camera viewpoint – and you fill in all those facial anomalies, totally erase all their muscles and give your model smoother skin. Sometimes – a pretty girl for example, shining the light directly into the face is a good thing (but try to avoid using a ring light).
The trade off is that you flatten the face and body, and lose most of the 3D effect you get from shadows. The shadow that defines shape is called “modeling”. Sometimes like with a body builder – shining the light directly into the subject will ruin the portrait.
Every photographic situation has trade-offs. It’s how you deal with them that will define your photographic vision or eye. Stepping away from taking photos of people for a second, here’s another example of how the angle of the light can change everything. Suppose you want to shoot a photo of a spider’s web.
Shooting spider webs can be done with hard light or soft light, but in my experience hard light makes a more dramatic shot. With the hard light of the sun, it is easy to see the thin filaments of the web as well as the glistening dewdrops in the early morning; assuming of course that the angle is right.
If the sun is behind the web (shining towards you), the spider webs seem to pop up everywhere. But if you are looking for them with the sun at your back, you could spend all day searching and never find one!
There is a spider web in the below photo on the left. The below photo on the right is much less obvious as the light is at our back.