Our derived interstellar extinction curve together with the comparison of different literature work. We used the mean extinction values over all fields. The red dashed line indicates a simple power law A_λ ∝ λ^-1.75 from Draine (1989), the blue line the power law of Cardelli et al. (1989) with A_λ ∝ λ^-1.61, and the green line depicts the power law of Fitzpatrick & Massa (2009) with A_λ ∝ λ^-1.84. The dot-dashed line in magenta shows the extinction curve of Fritz et al. (2011) in the Galactic center.