Options for positioning the ball include holding it in your own hand and in front of the model, asking the subject to hold the ball out in front of them, or by positioning it on the ground or on an elevated inanimate object.
If the former, you’d need to have the model laying on the ground as well as doing the same yourself to achieve a low viewpoint. It takes some experimentation but the idea is to try different options and have fun. In terms of equipment, you’ll need a camera and a kit lens for basic shots. A 16mm is ideal for APS-C cameras or 24mm with full-frame cameras, which will provide a workable focal length to include your’s or the model’s hand holding the ball in the shot. If, however, you’d prefer to exclude the hand and have just the ball in the picture, you’ll need to shoot with a macro lens.
Set focus mode
If shooting with a standard lens, use single-shot autofocus and have a single AF point active to fit your desired composition; if you shoot a tighter composition that requires a macro lens, you’ll likely achieve better results with manual focus. Set focus
to the distance of roughly the end of your arm and move the ball backwards and forwards until a sharp image can be viewed within.
Set your camera to aperture-priority mode with aperture set between f/2.8 and f/5.6. When shooting landscapes, you need a narrower aperture such as f/8 to ensure a sharper image throughout the ball, but for portraits you only need the centre of the ball to be sharp so wide apertures work well. Assess exposure and set an ISO rating that allows for a fast enough shutter speed.
Consider subject distance
With the lens ball creating a similar effect to a fisheye lens, it’s important that it isn’t held too close to the model because this will distort facial features out of proportion. Aim for the ball to be around 1m away from the subject to capture them relatively naturally, with the surrounding environment curving around them to create a framing effect that includes the edge of the ball.