Daylight factor is one of the physical parameters affecting indoor environmental. We can determine this factor in many ways. The main ways are computational methods, in situ measurements and finally measurements in architectural models. Measurements in models enable us comparison both measurements under real sky and under artificial sky. We can study changes in internal conditions - the colors and variability of the interiors and potential variability of window openings. Using of mini - photometer head in measurements enable us to give precision quality of design daylight in interior and validate computational methods for the real space.