Hα flux derived from the MEGARA data superimposed with the contours of the narrow band HST images of the Hα emission from Masegosa et al. (2011) and HM22 for NGC 4438 (total flux accounting for all components), NGC 4750, and NGC 5055 (only primary component of the emission lines). The inner black circle and the black crosses indicate the PSF region and the photometric centre. The contours for NGC 4750 and NGC 4750 represent the 3σ, 5σ and 10σ (black, grey, and white) flux levels of the narrow band image, with an extra contour at 100σ for NGC 4438 (black, black, grey, white).