There are cosplayers. Fan convention attendees may toss a colander onto their heads and make R2-D2 noises, but the serious cosplayers on “Heroes of Cosplay” spend hours and hours, and dollars and dollars, creating costumes and makeup to replicate fantasy characters in faithful detail. Hit movies are also fertile territory for cosplayers like Becky Young, who will remake herself as Merida from Pixar’s “Brave.” She’s so obsessed with detail, batman costumes she sharpens her archery skills to prepare for the role.