Jump to content


Photo

how can I color correct dead grass in after effects?


  • Please log in to reply
11 replies to this topic

#1 jonathan grant

jonathan grant
  • Basic Members
  • PipPip
  • 15 posts
  • Producer

Posted 19 July 2011 - 08:53 PM

In our film there is one scene shot in March where the grass is mostly dead, so it's that dead yellow color. We need to make it look like summer grass. The actors walk across it so we were playing around with after effects "change to color". It isolated the grass really well, but we can't figure out how to make it look like the right color. No matter what we try it looks like fake neon easter grass! You'd think it'd be as easy as choosing the right color in the "To:" box, but it doesn't look anything like the color we choose. Sometimes the darker the color we choose the lighter the color it becomes.

I'm not familiar at all with this effect.

Any suggestions on the best way to turn dead grass into summer green grass? (without having to manually mask out every frame of the actors walking across it)
  • 0

#2 John Mastrogiacomo

John Mastrogiacomo
  • Sustaining Members
  • 210 posts
  • Other
  • Las Vegas, NV

Posted 19 July 2011 - 10:42 PM

What you have to do is isolate the yellow grass and then adjust the hue, saturation, etc. to match the green grass. This way you will get the variations in color so it will look natural.

You can't just change all the yellow grass to one color with "change to color". Grass has many different shades and textures.
  • 0

#3 Mark Dunn

Mark Dunn
  • Basic Members
  • PipPipPipPip
  • 2420 posts
  • Other
  • London

Posted 20 July 2011 - 03:35 AM

You're lucky.
Antonioni had to paint it beforehand.
  • 0

#4 jonathan grant

jonathan grant
  • Basic Members
  • PipPip
  • 15 posts
  • Producer

Posted 20 July 2011 - 05:27 AM

What you have to do is isolate the yellow grass and then adjust the hue, saturation, etc. to match the green grass. This way you will get the variations in color so it will look natural.

You can't just change all the yellow grass to one color with "change to color". Grass has many different shades and textures.


We actually had good response from the change to color in that it isolated all the grass, the problem is getting the right color. If what we were going for was to make the grass look like fake neon easter grass, then we did great! lol But, we want it to look like spring/summer grass (which looks different than fall grass). I'm just not sure how to make the color look right. Anyone familiar with the change to color effect?

We could use another effect to change the color, but we'd have to mask around the actors walking on it in each frame which would be a nightmare to get to look right.

Maybe we could try keying out the yellow grass and put a duplicate layer underneath with the color correction?
  • 0

#5 John Mastrogiacomo

John Mastrogiacomo
  • Sustaining Members
  • 210 posts
  • Other
  • Las Vegas, NV

Posted 20 July 2011 - 03:09 PM

We actually had good response from the change to color in that it isolated all the grass, the problem is getting the right color.

We could use another effect to change the color, but we'd have to mask around the actors walking on it in each frame which would be a nightmare to get to look right.


You need to take the key from your change to color tool and use that to drive another tool to change the color. I used Fusion to test it and it's extremely easy to do.
1. Pull the key
2. Use two inputs to the color corrector. Input is the original footage, key is from the keyer.
3. You're done.
  • 0

#6 jonathan grant

jonathan grant
  • Basic Members
  • PipPip
  • 15 posts
  • Producer

Posted 20 July 2011 - 08:39 PM

You need to take the key from your change to color tool and use that to drive another tool to change the color. I used Fusion to test it and it's extremely easy to do.
1. Pull the key
2. Use two inputs to the color corrector. Input is the original footage, key is from the keyer.
3. You're done.


Hmm, I'm not sure I understand. I've never used fusion before. I tried it again today and the change to color tool isn't working well at isolating the color. :-/ I tried making it a color that I could key, but that didn't work either.

Here's a screen grab from the scene. http://i1.creativeco...5/deadgrass.jpg

I tried masking just the trees and doing a change to color on the leaves to make them a little greener. That worked okay, but it made a noticable difference on the treebark. There's just way too much pale yellow in the scene, it's everywhere! I was able to get a workable looking color using curves for the grass, but I had to mask just the grass and there's too much spill over onto the actors. Besides, the mask just doesn't quite look natural in certain areas (like where the grass meets the trees and the building in the back.
  • 0

#7 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7116 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 20 July 2011 - 09:20 PM

Looking @ that shot; I honestly don't see much you could do to get it looking "summerie" or "springie." It might be better just to try to re shoot or nix the scene
  • 0

#8 Vincent Sweeney

Vincent Sweeney
  • Sustaining Members
  • 686 posts
  • Director
  • LA at the moment.

Posted 22 July 2011 - 02:08 AM

An actual colorist can work wonders.
  • 0

#9 jonathan grant

jonathan grant
  • Basic Members
  • PipPip
  • 15 posts
  • Producer

Posted 22 July 2011 - 08:49 AM

Looking @ that shot; I honestly don't see much you could do to get it looking "summerie" or "springie." It might be better just to try to re shoot or nix the scene


Well, I would agree with you except there are a few things that might save it.

One, we never say what season it is. The majority of it was shot in the spring where the weather really was teetering back and forth between chilly and nice. So, the scenes go back and forth between wearing jackets and short sleeves. Pants are always worn, though.

Two, this is supposed to be a foreboding house so the dead trees actually work really well. There are some leaves on them but they are brown. So, putting leaves back on the trees isn't really necessary. That helps. We do want it to look kind of dead, but have enough green that it doesn't look too jarringly obvious that it's a different month from other scenes.

The sky isn't great, but maybe we can key that out? Luckily the sky is mostly covered up by trees and given that it's a pretty quick establishing shot we might be able to get by with the overcast sky, or hopefully key it out and replace with another sky.

I think changing the grass to a greener shade and changing the brown leaves to a greener shade will be enough to sell it. Test audiences will confirm or refute that. The biggest problem is that there's just so much of that brown in the picture!
  • 0

#10 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7116 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 22 July 2011 - 08:57 AM

I wish you luck. Only thing I could really think of would be roto'ing out the grass now and replacing it with newer grass and then yellowing it down to match...
  • 0

#11 Chris Burke

Chris Burke
  • Basic Members
  • PipPipPipPip
  • 1675 posts
  • Boston, MA

Posted 23 July 2011 - 09:11 AM

how about a shot of what you are trying to match it to? I think that your answer may lie somewhere in between. The two different looks are altered to look more like each other, but not exactly. Also your edit can help you out as to where the two scenes are in the time-line. True, a skilled colorist can do wonders, but the amount of work and the end result may be just as expensive as re-shooting. Thematically, can the different looks be justified??
  • 0

#12 Will Earl

Will Earl
  • Basic Members
  • PipPipPipPip
  • 385 posts
  • Other
  • Wellington, NZ

Posted 25 July 2011 - 09:34 AM

You can use a Hue/Saturation effect (under the Colour Correction filters) to adjust something like this. You select the colour range you wish to alter (in this case you'd want to isolate the yellow range). Then any hue, saturation or lightness changes you make will only affect that range.

It's likely you may also need to do some rotoscoping to isolate the correction from other aspects of the shot (jacket, hair, car, tree trunks). Yes this might require some effort, but truth is - stuff like this does often require some effort in order to make in work - you can either try your best to fix the shot in post or reshoot the shot/scene.
  • 0


Opal

CineLab

Rig Wheels Passport

Technodolly

Broadcast Solutions Inc

FJS International, LLC

Wooden Camera

Ritter Battery

Glidecam

Aerial Filmworks

CineTape

Willys Widgets

Media Blackout - Custom Cables and AKS

Gamma Ray Digital Inc

rebotnix Technologies

Paralinx LLC

Abel Cine

Visual Products

The Slider

Metropolis Post

Tai Audio

FJS International, LLC

Media Blackout - Custom Cables and AKS

Rig Wheels Passport

CineTape

Glidecam

Willys Widgets

Gamma Ray Digital Inc

Broadcast Solutions Inc

Technodolly

Visual Products

Ritter Battery

rebotnix Technologies

Opal

Tai Audio

CineLab

Wooden Camera

Metropolis Post

The Slider

Abel Cine

Aerial Filmworks

Paralinx LLC