Multiwavelength time-distance diagrams of the filament eruption obtained along the slit S1 (filament apex). The vertical axes denote the apparent vertical distance in the plane of sky measured from the initial position of the filament apex. Panels (a), (b), and (c) show different characteristics of the eruption that become more evident at specific wavelengths. At Hα ± (0.25:2.0 Å) the slow-rising phase and the initial acceleration are observed, at Hα ± (2.25:4.0 Å) the main phase and fast acceleration have manifested, and at Hα ± (4.25:6.0 Å) the fastest-ascending phase is visible. Panel (d) is a composite time-distance diagram, which helps visualize the complete picture of the eruption and demonstrates that the line of sight velocity of the erupting filament also increases as a function of distance and time. The inset color-bar depicts the corresponding line of sight velocity of the wavelength range indicated in panels (a), (b), and (c). The dashed line is the fitting of an exponential function to the selected points along the erupting feature in the plane of sky.