You can't get "clear" pieces from using clear FDM printer filament, mainly because of the infill. From what I've seen, you can get better results with clear resin, but only after you polish it up. Otherwise it's opaque. Also, regular clear looks a little yellow, so I've heard to use a few drops of blue dye mixed in to help it look more clear. I have both kinds of printers and I have both clear 3d filament and clear resin. I've yet to use the clear resin yet though.