While Fox distribution chief Chris Aronsonclaimed that Fox supported Trank's version of the film,Kebbell conversely stated, "I tell you, thehonest truth is [Trank] did cut a great film that you'll never see. That is a shame. A much darkerversion, and you'll never see it."Trank further disowned the film by removing it from hisInstagram filmography.After Stan Lee's death three years later, Trank lamented that he had "let him down", even though afterthe film's release, he had received a personal letter from Lee asking him if he was okay.In 2020,Trank has admitted that much of the sequences he had planned had gone unfilmed, thus making adirector's cut practically nonexistent.Later that year, Kate Mara admitted that her experienceworking on the film was "horrible". While she did not go into great detail, she implied that much ofher discomfort came from questionable directions stating, "I think that speaking up is something thatI think that we all probably learn it [sic] over and over again... I don’t regret doing it at all, but doregret not having stood up for myself. I regret that for sure."The film used the Los Angeles-based company OTOY for its visual effects. Moving Picture Company,Pixomondo, Rodeo FX and Weta Digital also created visual effects for the film.MovingPictures Company took on the visual effects for The Thing, rendering a fully digital character based onJamie Bell's on-set performance and the Human Torch's fiery visual effects. Weta Digital handledReed Richards' stretch effects. Pixomondo delivered Sue Storm's force-field and cloaking effects andaugmented Doom's costume. James E. Price served as the over-all visual effects supervisor.Kinberg stated that the film would be converted to 3D in post-production,but those plans werecanceled, with Trank stating that he wanted "the viewing experience of Fantastic Fourto remain aspure as possible for the audience, which means in 2D".A sequence showing The Thing performinga "dive-bomb" in the film was cut due to budget constraints.The studio was caught off-guard by the first cut of the film for having a "morose tone". The ending hadnot been finalized and the studio hastily had to cobble together a new ending that was essentiallycomposed of script pieces of the original draft, plus new ones that were being written on the day ofreshoots. Much of Trank's suggestions were swiftly ignored. Stephen E. Rivkin was hired to edit themovie together with Trank referring to him as the "de facto director" for the new cut. Despite Trank'sefforts by having two edits of the film, Rivkin's was ultimately chosen over his.Post-productionMusic
In January 2015, Marco Beltrami was hired to compose the film's score.Philip Glass was also hiredto work on the score with Beltrami.