TMZ obtained photos that were taken out in London Sunday afternoon, where the actress was in full costume portraying the late singer. As you probably know by now, Marisa was tapped to play Amy -- but people online are crying foul, saying it's a complete miscast.

Considering the massive amount of criticism early set photos received in the past few weeks, you might've thought the studio would make a tweak or two to Marisa's makeup or something -- but alas, as seen in these pics, they're forging ahead with what they got here.

Unclear what sort of scene they were shooting exactly -- but eyewitnesses tell us it looked like Amy's onscreen dad, Eddie Marsan, was dropping her off at a rehab center. That would make sense ... this film is focusing on Amy's rise to fame in the early aughts, when she was still living in London. By then, she'd already been using substances, alcohol and otherwise.

The backlash over Marisa's casting is likely to continue as the movie moves along in production -- frankly, MA looks nothing like Amy ... and while the real Amy Winehouse's own father says it's not a big deal at all, that's likely not gonna appease the diehard fanbase.

It's a bit weird everyone's so riled up over the fact Marisa's not a dead ringer for Amy. Truth be told, Hollywood's been in the habit of casting actors who don't necessarily look exactly like the iconic musicians they play, especially of late. Austin Butler excluded, of course.

Plus, ya gotta imagine that the producers -- who are working on this with a blessing from Amy's estate -- want to do her legacy justice ... so a little trust goes a long way for this sort of thing. As they say, it's not always about the look -- but, more so, the essence.

Bottom line ... Marisa still has the potential to wow everybody, so we'll just have to wait and see what comes of the performance when 'Back to Black' eventually hits theaters.