The practice of fixation, with or without a visible object, is equated with shamatha meditation (zhi-gnas), attaining a state of calm, according to the Dzogchen viewpoint.
The practice of vision, whether with the empty sky or with sunlight as the support, is equated with vipashyana meditation, or higher insight (lhag-mthong).

In Samatha the in and out breath is often the focus of the concentrated attention. The purpose is to develop “strength” to enable good Vipassana.
Vipassana is known as “Insight” meditation or “Mindfulness”. The concentration from Samatha is focused on the surrounding phenomena — sights, sounds as example, to perceiving them directly, instantly and vividly.