We will show the status of the H-alpha imaging we carried out for NGC2770 with the OSIRIS red tunable filter. This galaxy is extremely interesting because it harboured 3 supernovae and one X-ray flash (a soft version of a Gamma-Ray Burst, GRB). The combination of the GTC data with polarimetric data we got with the VLT (+FORS1) allowed us to compare the properties of the explosion sites of standard supernovae and X-ray flashes. This study is aimed to shed light on the impact that the birth-place has on the formation of a SN or a GRB. We plan to extend this study to [OII] and Hbeta as soon as the blue OSIRIS tunable filter is ready.