outdoor compositing/green screen

[hidalgo]

hi there
im doing some green screen cleaning and compositing for a scene in a movie, the problem is that i cant have the right feeling on that shot, couse they look too much indoor, i know that the main problem is actually in shoot lighting but there is any chance to imporove more the compositing giving more the "outodoor" feeling, couse i feel them too much stick to the background...
ive attach a sample scaled and not graded at allhttp://www.thorsteinmovie.com/post_production/test.jpg...
thanks for any help

Hidalgo

[hidalgo]

some magic tips? i most colour the actors too? couse i would prefer to just match foregraound, couse we will do the colour grading after... or?

[Sketch]

The colors aren't that bad, it is the light which destroys everything. In the BG you have a strong back light, but your FG is very bright and a lot of light is coming from the right hand side, where there sholudn't be any light source.

[hidalgo]

so you suggest to maybe flip bk? or to make fg less bright?

[Sketch]

Maybe flipping will help a little bit, but the general lighting is still a problem. There is too much light in the front. I guess reshooting isn't an option? Maybe you could add a little light warp, so the edges blend in more nicely.

[m1jackson]

You could also increase contrast in your foreground plate and darken your shadows. This will help to punch the rim lights more.

[hidalgo]

actually the shoot as already 3 lightwrap on it :) i try to add contrast, flip fg and post another angle too..
:)

[grinner]

a little matte blur would do wonders. Color correct as best you cna and shoot that stuff outside next time. Keep in mind the sun's location as ya shoot.

[hidalgo]

you mean to increase the edge blur?

[Loud]

If you have time to do the roto, you can create a shape along the left edge of the two subjects to use as a grading mask, just to punch up the apparent exposure in those areas and lower it in others to create the illusion that they're getting that strong backlight. Try it on one frame and see if you can pull a good look off, and then try a second or two and see if it works in motion. Time intensive though, if you're up against a deadline (especially if the shot is really long).

You could try and cheat it by blurring your key some, transforming it to the right, inverting it and finally multiplying it back with the original alpha channel to create the edge shape for you. Quick and dirty, less control, but it might work out.

Just a couple things I'd try.

[hidalgo]

thats interesting!! : )
sorry if i ask more info...but can you please explain me that tecnique a little bit more further?
i mean the second part where you mention to blur my key...
thanks for your tips by the way..

[Loud]

Are you working in Nuke, AE or something else? I'll try to be as generic as possible, but if you aren't using Nuke or AE, I couldn't tell you exactly how to accomplish what I'm thinking.

Take the alpha channel of the subjects, we'll call that a, and then take a copy of it, b, and invert it, so now b is black on white. Then blur b however you want, and transform it, so it's offset from a, away from the light source. Then multiply a and b together, so you get an intersection of where they're both white. This will create a mask that will automatically follow the edge of your characters, so you can use it for a color correction mask to adjust the relative exposures on the edge versus the sides facing camera.

The mask will look kind of like a bevel effect, and actually, if you're using After Effects, you can use the bevel/emboss layer effect to create this mask without doing all the steps.

[Loud]

If you happen to be using Nuke, here's what I threw together. It uses an animated bezier shape, and shows how this edge mask only faces in the one direction.


set cut_paste_input [stack 0]
version 5.2300
Constant {
inputs 0
channels rgb
name Constant1
selected true
xpos 100
ypos -271
}
Bezier {
cliptype none
points {{
{988 1196 66.7 -0.17 66.7}
{1480 940 75.7 -1.04 75.7}
{1260 732 75.7 -1.61 75.7}
{1464 504 76.5 -2.05 76.5}
{1056 340 109.9 2.94 109.9}
{704 656 76.2 1.73 76.2}
{984 776 76.2 1.44 76.2}
{756 1064 66.7 1.56 66.7}
} {
{261.3 892.7 66.7 0.97 66.7}
{681.1 1217 75.7 0.1 75.7}
{773.3 942.5 75.7 -0.47 75.7}
{1053.2 1028 76.5 -0.91 76.5}
{1031.7 607.9 109.9 4.08 109.9}
{616 429.3 76.2 2.87 76.2}
{624.3 720.6 76.2 2.58 76.2}
{282.7 638.3 66.7 2.7 66.7}
} {
{1580.7 1445.1 66.7 -0.76 66.7}
{1845.9 958.1 75.7 -1.63 75.7}
{1547.3 908.3 75.7 -2.2 75.7}
{1589.2 605.3 76.5 -2.64 76.5}
{1159.2 697 109.9 2.35 109.9}
{1043.6 1155.7 76.2 1.14 76.2}
{1342.9 1098.9 76.2 0.85 76.2}
{1314.5 1465.2 66.7 0.97 66.7}
}}
shape {{curve L x1 0 x50 49 x100 99}}
center {1024 778}
name Bezier1
selected true
xpos 100
ypos -174
}
set N196ef1f0 [stack 0]
Invert {
name Invert1
selected true
xpos -12
ypos -132
}
FilterErode {
size 60
name FilterErode1
selected true
xpos -12
ypos -87
}
Blur {
size 91
name Blur1
selected true
xpos -12
ypos -45
}
Transform {
translate {112 -30}
center {1024 778}
name Transform1
selected true
xpos -12
ypos 4
}
push $N196ef1f0
Merge2 {
inputs 2
operation multiply
name Merge1
selected true
xpos 100
ypos 45
}

[hidalgo]

amazing man, thanks so much, by the way im using nuke for all the compositing i will post some more frame later to show you how ive manage you tecnique...
again really thanks :)

[Hugh]

I've annotated the image to show where I think the main issues are...

The main problem is that there are two main lights on the foreground - one in the right place and one completely off to the wrong side...

So, in the image below, I've marked up the two light sources with directions (the arrows) and what is telling me the direction (the circles)

http://www.vfxtalk.com/forum/attachment.php?attachmentid=9331&stc=1&d=1268230852

The one that I've marked up in green is great - this is exactly where your light is coming from, and works well. However, there is another one, marked up in blue, which is really killing it. It's mainly the shadows on the girl on the right's neck that does this.

This is a regular problem with shooting in a studio - most of the lights are hard shadow-casting lights, where what you really want for your fill (the blue) is a huge soft box)

[hidalgo]

ok, those 2 are two updates, still anway wihtout your suggestion, i will put the new versions with your tips online i hope today so maybe you can tell me if ive done everything correcty, hope its not a problem and thanks again to be so kind.. :)


http://www.thorsteinmovie.com/001.jpg

http://www.thorsteinmovie.com/002.jpg

http://www.thorsteinmovie.com/003.jpg

http://www.thorsteinmovie.com/004.jpg

[sathees]

you need to color correct your FG to match it with the BG's light sorce.
I will try my own with some rough rotoing i think it will help you maybe......