You can configure the 3D view with a lot of parameters that you find in the scene settings inspector by tapping on the scene settings icon () in 3D view.
There are quite a lot of settings. You can scroll up and down. Here is a complete list of all settings. Various settings are described in detail below.
Setting up the lights
The first part of the scene settings are used to adjust various light settings. Copper uses spot lights to illuminate the scene. The center of the spotlight is always locked on the center of the PCB. To keep the light interface simple, Copper automatically calculates the height of the spotlight (relative) to the floor. Just think about a sphere enclosing the scene, you move the spotlight on this sphere. You only set the position of the spotlight relative to the PCB. The farther away the light is from the PCB, the lower the light.
This image should give you an idea how it works. It's like in nature. When sun goes up, shadows are long and intensity is low. Midday the sun is straight above the scene and shadows are short and hard. Copper uses the same system. Just play around with it.
Tap or pan the light settings control with one finger to adjust the light position. You can see the light intensity and shadows right in the view. Adjust the light settings to your liking. You can also pinch to adjust the distance between the spotlight and the PCB. Taking the system explained above, by pinching you adjust the sphere radius enclosing the view.
Adjusting various other settings
Just use the sliders to adjust various other settings like the cone angle of the spotlight. Play around with the values, you should quickly get a feel.
Depth of field
At the bottom of the settings, you can adjust depth of blur. This gives a very dynamic effect and looks great if you are very close to the board. Use the aperture setting to adjust the size of the sharp area in the image. The larger (slider to the right) the more area of the image will be sharp. A small value will unsharpen most parts of the image.
Use the focal distance value to adjust the position of the sharp area relative to the camera position. You will need to play around with this value.
Last but not least, you can adjust the amount of blur to apply to the unsharp areas. If you want to turn depth of field off, just grad this slider to the left (default).
All of the scene settings can be stored as a preset. This way you can quickly restore a specific camera angle or light settings. More on presets here: Presets of scene settings.