In light of various theories surrounding Derren Brown's predictions, I was wondering how seamless split screens are accomplished. I'm aware of the basic split but any shadows or differing light are easily noticeable. Especially one Youtube user who demonstrated how Derren may have you split screen, I was wondering how people bypass the issue of any shadows overlapping the split screen, and how, if Derren DID do this, one side of the screen can be completely different even though the camera is shaking (i.e. the main theory surrounding last night's Event)
and how, if Derren DID do this, one side of the screen can be completely different even though the camera is shaking (i.e. the main theory surrounding last night's Event)
Many thanks
It's possible that the shake isn't being done manually but with the aid of a pre-programmed sequence using mechanics.
Back around Christmas time the Real Hustle team did something similar (I think under a different programme name) where the a CCTV camera footage effectively had a split screen. In this case it was done with the aid of half a still photo dropping down, and quick distraction of those watching the footage whilst it's dropped into place.
1. Arrange for your live artist to never cast a shadow over the area you're masking with the split-screen. In other words make sure Derren stays on the right hand side of frame on his mark and doesn't move when the mask is there. Make sure your lighting doesn't cast shadows where you don't want them. If you are clever you might be able to design an asymmetric mask or use a painted mask that only masks what you need and leaves space for shadows elsewhere.
2. Just because the image you're are seeing is wobbling doesn't mean the camera has to. You can shrink, zoom, and reposition video images live. That is how news galleries put reporters and studio cameras in boxes over graphics - they are called DME or DVE devices and have been around in one shape or form since the mid 70s (though the quality has improved a lot since then!) The kit they've got could animate those boxes - but just because you can, doesn't mean you have to! To make a static camera look wobbly, programme the same bit of kit to do a permanent 5% zoom in, but to zoom in and out a bit around this point, and to twitch left/right/up/down a bit in a similar manner to the way people imagine a handheld camera might. No mechanics required. HOWEVER - the wobble isn't the same as you'd get from a real hand held, as the camera is not actually moving relative to the scene being shot - so you get no parallax or depth cue changes.
3. Do the split screen/mask upstream of the DVE/DME wobbling process and you can make a split screen between a static recording and a static live camera merge and wobble as if shot wobbly at the same time.
It was well done - but isn't an amazingly complex thing to do live. The One Show beamed a reporter live onto the sofa next to Patrick Stewart when he was on using a similar technique (record the empty sofa just before the new guest sits in. When you're live cut to the split screen of the recording and live shot of the sofa and then remove the mask to reveal the new guest on the sofa. And notice the cleaner disappear in the background!)
Thanks for that guys. On the subject of shadows, I'm aware that the key is to keep shadows away from the area of the screen you're removing. But here, http://www.youtube.com/watch?v=rqAt2akPHJ8 shadows have been deliberately cast onto the other side of the screen. However, the shadow is not cut off, yet his arm is. How is that achieved?
Thanks for that guys. On the subject of shadows, I'm aware that the key is to keep shadows away from the area of the screen you're removing. But here, http://www.youtube.com/watch?v=rqAt2akPHJ8 shadows have been deliberately cast onto the other side of the screen. However, the shadow is not cut off, yet his arm is. How is that achieved?
You can see on that video during the "reveal" where he has a very blurred shadow on the wall, seperated from his actual moving shadow.
Thanks for that guys. On the subject of shadows, I'm aware that the key is to keep shadows away from the area of the screen you're removing. But here, http://www.youtube.com/watch?v=rqAt2akPHJ8 shadows have been deliberately cast onto the other side of the screen. However, the shadow is not cut off, yet his arm is. How is that achieved?
The guy is standing there for the pre-recorded bit (used to mask the left of frame) so his shadow is cast during the pre-rec - however notice that the shadow isn't moving (and the guy cleverly doesn't do huge movements once the mask is there so it doesn't look odd that the shadow isn't moving) Using a soft edge on the split screen rather than a sharp edge can also make the seam far less visible.
Different case to Derren - where the black floor helped with dark shadows not being too visible - and the brick wall was a long way back and so didn't have major shadows cast on it. (It was also quite a busy pattern so would make the split screen joins more tricky to see)