# Greenscreening



## Model Man

*The Ultimate Diorama*

I'm just getting into this myself. 
Anyone have any camera/lighting tips, let me know!
This is my most recent installment.


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## Model Man

Here's the others in the series so far.


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## Model Man

Interim Report:
Coming up we're going digital!
Primarily I'll be using Adobe's After Effects program to assemble (comp) a bunch of shots. Another useful program is Autodesk's Combustion for particle work such as lasers, explosions and smoke. Finally, I may touch on some Alias Maya for some setups. We'll see about that though. Maya would involve advanced trickery, so that will be time permitting. There are some 3d cheats that can be done in After Effects.

Be well.


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## Prowler901

This is some great stuff. I really appreciate all the time you put into your youtube presentations.

And, that's a cool "Axe" hangin' on your wall. What is it?

Todd


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## Model Man

Thanks on the good words. This is fun stuff for me to do, so it's no trouble.

She's a Dean Edge, 4 string fretlless. Beautiful tone. I've had her almost 4 years now. No chance to gig or jam w/ her much yet, but I take her down a couple hours a month. The 20w gorilla ain't got that much growl for her. 

Pairing her up with a hundred dollar beater to hack around with is ideal. And if I can rig up a bass synth again like I had w/ my Ibanez five years ago, I'd be going symphonic.

As it happens, if finances don't turn around, she's for sale again. No one went for her a month ago. Hoping I don't have to risk her on the block again.


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## Prowler901

Sounds real nice. I hope you don't have to put her up for sale again. I've only been learning to play 6 string for the last year. My middle son and I have been working a bit harder at it in the last couple weeks. We enjoy the time together.

Keep up the hard work. 

Todd


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## Model Man

Great, so you've shot some greenscreen footage. Now what?!?
Here's another batch of greenscreen vids. This time, they deal with the computer side.

*Diving into After Effects*









*Pulling a Key*









*Stabilizing footage*


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## roadrner

Great videos! :thumbsup: rr


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## Model Man

Motion Tracking in two parts


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## slingshot392

I just started watching these videos, this is great, I never would've thought of this even though I have seen this done enough on different shows.

Not sure if the background color makes a difference, some time ago, the local news showed how they do their weather maps and they would use a blue screen instead of green, the guy said that was one reason they were never allowed to wear a certain shade of blue. On April Fools' Day, the guy wore a blue turtleneck to all you could see were his hands and head.


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## Model Man

Technically, any color can be used. The major condition is that it must be evenly lit. Minimal hot spots and/or shadows. And the color should not occur in your scene. Or if it is, easily masked off later. 

Green, Blue and Orange is the order of 'preferred colors'. Movies started off with blue, tv started with green. Rarely if ever is orange used.

Green and blue worked best for the cameras of the day (1930's, 1950's), film vs. video. 

In these modern times, film stock and cmos/ccd's are vastly improved. There are hold-outs based on tradition (and probably cost to replace all that material), but green has become more common in film and blue more common on tv. 

The truth is both colors, chroma blue and chroma green -or their equivalent colors, are required. Green is, ultimately speaking, that bit better than blue and for one major reason. Spectra. Let's look at 'em.

Red is a long waveform. It therefore 'washes over' small noise such as dirt and seams. This makes it a good candidate for chroma keying. However, red also tends to smear due to this fact. And, as red ultimately occurs in all flesh tones, it can't be used for people. Two strikes.

At the other end, blue has a tight wavelength. This is great for getting details. The downside here is that this picks up lots of noise. This can wreak havoc with digital cameras as most compression will occur in the blue channel, thus compounding your hair loss. Two strikes.

Sitting happily between these two colors however, is green. It gets the best of both red and blue without their harsh negatives. But, being a compromise, it is not the perfect solution either. One strike. 

And as CFL's are perfect due to their spectra for lighting green, green wins. 

Despite my using green walls in the series, I do need a swappable blue version as well! But if you ask me, one or the other, I go with green. Though most of my life I was a traditionalist.

And just as you don't want to wear blue in front of a bluescreen, you don't want to wear green in front of a greenscreen. I have a video coming up showing my green D-7 against the greenscreen. It's bad stuff. I'll be showing that off in the near future and how to save it.


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## slingshot392

Thanks for the information, great stuff. All kind of beyond me though, never been much of a photographer. I now have a halfway decent digital camera so I'm starting to practice some more, still hit and miss though.


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## ModelKitBuilder

I subscribed to your channel.

I just started out with using YouTube to showcase past personal and commission projects, and what I am currently working on in my studio.

I am currently using Windows Movie Maker to put my videos together.

Keep up the good work! :thumbsup:


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## Model Man

A few weeks ago, (my portion of) Los Angeles was struck w/ some nasty humidity which knocked my (paper) wall down. 

Rather than rehang it, I ebayed a big sheet of green cotton/muslin weave billed as a 'green screen' for $35 shipped. As this is the same relative cost as the paper wall was, I figured I'd give it a shot. Note that this is not 'proper' greenscreen material. The real stuff is a foamy-lycra like fabric that is nearly 100% green and nearly 0% blue and 0% red (the ideal) and a 6x9 sheet of the stuff would cost $100+ on a good day. 

There are more experiments and work I need to do, but here's the results so far. 

*The short:* 
-The fabric has a huge blue component, which will make keying more difficult than the neon green posterboard which has little blue in it. They both have similar red levels. This is important as the more pure the tone, the easier it is to key. I'll post a pic of the comparative alpha's to demonstrate what is going on and why.

-Posterboard comes in sheets which must be seamed together but is flat across the wall, whereas fabric drapes and wrinkles -which are difficult to smooth out. 

-Seaming the posterboard together means you can scale your wall to any size whereas the fabric must be trimmed and preferably hemmed to maintain strength. 

-Both cost about the same. Both are easily taken down/stored/replaced, disposed of. Both easily rip or damage. Neither is the right stuff, but for utter cheapskate prices, they are good enough-to-excellent.

*The long:*


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## StarshipClass

To flatten it, you can use some of the spray glues--3M is the best I've found so far--and glue it to a flat surface (Cardboard? Wall? You could use cardboard for the corner to smooth it out and glue the fabric to the wall if that's allowable.). Glue it a little bit at a time to make sure there are no significant wrinkles. You should be able to pull it apart if you goof before it's had a while to dry.

You may be able to rectify some of the green color by altering the lighting using filters and/or increased wattage, angle, etc. 

Also, you might be able to find a broken old office chair on rollers on which you could mount a sturdy piece of pipe. With that, mounting a light that stays the same relative to the model would be much easier and you could roll it around as needed, etc.

If you put the camera on such a mobile mount and put some sort of makeshift railing (2X4's?) to keep it straight, you could "whoosh" past the model (on a fixed stand) with the camera for a motion effect. You'd need a smooth floor for this to avoid bumps, however.

Also, have you tried pulling the lights back so that the light will hit the green screen? Even if bouncing off the ceiling, you might be able to get a more filling effect from the light.

Also, if you have your model in the center of the scene in camera and need to cover up some studio structure (say as in doing a distant shot) you can always use the video editing program to put a green matte on top of the scene with a cutout area in the middle for the model to be visible.


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## Model Man

-One of my YT'ers suggested I glue the fabric to plywood boards. Problem w/ that premise is that a fabric wall now becomes a genuine, very heavy and expensive goliath that could easily fall and cause other headaches. Far too restrictive in terms of packability for a move, or the need to take it down for a day or any portability/storage/cleaning/repair issues. Using simple thumb tacks will be the best option here as they can double as tracking markers and will cost about $1. And while the corner won't be round-smooth, it only has to negate the shadows a 90° corner creates.

-When my budget allows for an upgrade, green gels go over the lights. ~$20 for an 8x10 sheet is not uncommon. Multiply that by 10 lights. Ouch. In this regard, there really are no cheap solutions as they have to be photographer-grade for color frequency and heat characteristics. Even cfl's become hot to the touch.

-I love this idea of cannabalizing an office chair!!! Very nice indeed. A well chosen base will likely be heavy enough to damp big jostles and create smooth movement over carpet. 

-I recently tore out the foot pads on my tripod and replaced them with rollers, the ball kind. However, they want to force the tripod in the direction they are set before they swivel in the direction I need them too. A different type of wheel should work out better. There's no way to lay down any form of track in the room and there's no way the carpet is getting ripped up. I have to rely on stabilizing footage in post, but a rolling tripod is still helpful. I've also just come across a vid demonstrating a homemade steady cam rig for about $25. That will occur when the budget allows and will beat the snot out of any non-motorized tripod. Regrettably, there is no way to do any moco work, so this setup will always be a low end situation.

The light positions as shown are in their ideal positions to throw as much light on the wall and no where else. Angling them at the wall produces intense hotspots that cannot be canceled out and throws more bounce into the room. The black velvet option is the ideal route for this setup for absorbing all excess light. The 2nd video posted at the top shows the lights angled down and how much light is thrown in the room. This is bad and must be avoided at all costs. Wall light needs to stay on the wall. Subject light needs to stay on the subject. Cross talk causes headaches in post. Minimizing this headache up front saves lots of hassle.

I haven't covered the roto/paint and rig removal installments in this series yet. That will cover what you suggest w/ the matting. I briefly mention it in one of those 'Enterprise' episodes above when it goes in front of the window. 

But speaking overall, the more you can avoid pitfalls with simple, up front measures, the more hassle saved down the line. It is most often the case that a fix that could take a shooting crew moments or minutes to fix saves dozens of hours in post and consequently massive dollars in the budget. And if you're the only one doing the entire process, you don't want to waste time roto'ing something a simple gesture could have fixed earlier. And of course, you have to have the inclination to go beyond pulling a simple key and do genuine repairs that can take specialists hours or even days to fix. 

And of course, the underlying goal here is to keep the setup as cheap as possible and show all the pitfalls inherent to the process. :hat:


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## Model Man

Light positions. Here are two good examples



















A world of difference!


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## StarshipClass

Model Man said:


> But speaking overall, the more you can avoid pitfalls with simple, up front measures, the more hassle saved down the line. It is most often the case that a fix that could take a shooting crew moments or minutes to fix saves dozens of hours in post and consequently massive dollars in the budget. And if you're the only one doing the entire process, you don't want to waste time roto'ing something a simple gesture could have fixed earlier. And of course, you have to have the inclination to go beyond pulling a simple key and do genuine repairs that can take specialists hours or even days to fix.


DEFINITELY! Do as much in-camera as possible and the post production will be a relative breeze vs. a monster headache.

For the "rail" I suggested it can be as simple as thick cardboard or thin plywood laid down on the carpet between two 2X4s to form a trench for the wheeled base to roll down smoothly. I prefer the 4-wheeled office chairs for this as they'll fit down the "rails" better.

I would still be tempted to put the fabric on four to six feet tall by two or three foot wide sections of cardboard that have been duct taped together so that you can fold it all up for storage or moving. You can then tack these to the wall and not have a whole lot of folds and shadows and such.


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## StarshipClass

Model Man said:


> Light positions. Here are two good examples
> 
> A world of difference!


What I was thinking is that you could still bounce the light. It looks from the video/photos that the light bouncing off the ceiling is so close to the top of the green screen that it's not filtering out and filling in to help smooth out the lighting on it.

If you could mount the lights the same but say two feet in front of the screen, you might fill in the lighting better. 

You could also use white sheets of poster board to bounce and scatter the light from the lights off to the side, perhaps, in lighting up the shadows of the green material.


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## Model Man

I see what yer saying now. Initially I had the ceiling lights about a foot further away, but I still got hotspots. If anything, I would next try putting them closer. They are about a foot away now, so halfing their distance and pointing straight up might put a more even glow down the wall, esp. w/ the floor lights bouncing up. For the moment, I'm keeping them as is as I got some mods going. But finagling their distance is a major concern still.

I dropped $25 on some black velvet to replace the black poseterboard. The difference is stunning, but I have not done any test shots yet. Also, to kill direct bounce from the ceiling, I'm going to use some spare green posterboard and run a scrim directly behind the lights. This will help kill the room bounce and put more green bounce directly on the wall. Hopefully that will amp the green channel a tad as the blue channel is too relatively strong at this point. 

And a company in the same building I was working at last week threw out piles of what they called 'junk' and I called treasure. Apart from some nice pieces of scrap wood I turned into shelves at my workbench, they also threw out a few wheeled chair stands. Wish I had the room to take two, but I did get one. It rolls beautifully on the carpet and all I need to do now is deduce a tripod mount for it. I'm sure it's gonna be cool, so thanks for that great idea as well!!!


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## StarshipClass

With the velvet, the thickness and roughness of the material kills a lot of the reflections by scattering and absorbing light rather than having shiny spots being reflected from the lights. Black felt might be brushed or rough sanded to get the same effect.

This site has a few hints--I'm sure there are other great places on the internet for tips/advice:

http://www.hollywoodcamerawork.us/greenscreenplates.html

Are you on any of the forums concerning such expertise?


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## Model Man

I visit the forums at dvinfo.net every now and then. There are a few others, too broad and industry related and not relevant to this topic. I've bookmarked that hollywoodcam site for ref. It looks like they cover all the mistakes really well and makes for great insight into the hassles I'm talking about here and how us modelers can minimize and/or avoid most/all of them w/ simple knowledge! 

My experience comes solely from cleaning bad screens for the last 2 years, whether feature, music vid or commercial w/ a couple recent on-set vfx assistant jobs. So, to some degree, this series is self-therapy in hopes that I can pass along my meager knowledge as specifically applied to our hobby to make the best shots possible. 

Digging thru my youtube faves (www.youtube.com.user/modelmantom), folks will find behind the scenes vids of feature film model shoots and post production reels of how models get integrated with 3d assets and composited into what you see on the big screen. There are dozens of clips, and I will make an attempt to link them individually here.

Please, anyone feel free to add more to this topic and school us all! Stuff like the Perfessors link above are invaluable for insight into shooting your models for later computer work -whether you photoshop a single still or dig into real compositing efforts. The best effort up front makes easier work for you down the road.


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## StarshipClass

^^A small list of reference sites and videos is a great idea!

I understand your frustration with trying to find something more related to what you're doing here. With just a couple of exceptions, I haven't found anything interesting nor very helpful for the level of animation and incorporating the model/computer background type compositing.


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## Model Man

It's certainly been a few months. This morning, I dropped the old cloth wall and put up a neon green sheet of felt. Benefits are that being thicker, it wrinkles less and drapes better. It should be easy to iron out the folds in the material now. I was worried about the rough surface, but in the few tests so far, it looks great. This may be an ideal material.

The muslin was too thin, wrinkled heavily and easily, draped, wouldn't stretch or stay flat. Also, it was too blue a green to be ideal.

I also made a decision on train rail, O guage is going to work best for me at this juncture. So now I need to get twice as much straight track and a sampler of curved tracks at various diameters. New, the prices will be exorbident.


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## Model Man

First ironing pass.


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## Model Man

Here's a look at two different floor track options. Each has it's good and bad. This is a slap-dash assembly of components. All the flaws to the situation as presented show themselves off well.


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