First panel: J-PLUS photo-spectra, corresponding composite images (upper-right inset image), as in Fig. 8 and composite – J0660, r, and i – image (lower-left inset image) of tHASH PN Jacoby 1. The extended PN is clearly visible, as indicated by the red circle. The H α emission is detected by applying a Gaussian smoothing filter of 10 pixels. Photo-spectra and corresponding images of lHASH PN TK 1 (second panel), pHASH PNe Kn J1857.7+3931 (third panel), and KnPa J1848.6+4151 (fourth panel) of the HASH PN catalogue.