Anyone Have Experience with Chroma Key?

[sm4him]

I might be looking for a green screen setup and I'm wondering if anyone has actual experience using one.

Here's the deal: My employer is hosting a conference in November, the state public transit association conference. My boss has this really, really horrible awful idea that she wants to do which involves using a green screen. So, I'm supposed to research this and see if it's doable--I'm torn, because on the one hand, I know it's doable and I'd like to play with the green screen…but on the other hand, I do NOT want to try to carry out her horrible, awful idea. Because it is going to involve her wanting me to do something that I do NOT have the graphic design skills to pull off--a little fact I have already shared with her, but she's ignoring me.

But, let's say we're gonna do it. Here's some of my questions, but if you have other comments related to having actually used a green screen, feel free to chime in with other stuff!

1. Are some green screens better than others? Should I be looking for a specific material or brand or anything?
So far, the ones I'm seeing tend to come in a kit, complete with lighting--but I wouldn't want that, because I already HAVE cheap-*ss continuous lighting that's still probably better than what's in these kits. I *would* however need the "frame" or whatever to hang the green screen on.
2. Do you NEED the software I'm seeing in order to process or is it just as easy to process them in Photoshop? Is the main benefit to the software packages that they come with a variety of backgrounds?
3. What would you recommend as a basic setup for doing green screen?

This would be done in our city's convention center (i.e. low light, probably mostly fluorescent, HIGH ceilings). We would likely be taking full body shots of each person, so the screen would have to be of a sufficient size to do that.

I have available to use:
D7000, D5100
Sigma 50mm f/1.4
Tamron 70-200 f/2.8
Two speedlights and stands
ONE soft box (can't remember what size, but pretty decent size) -- I could easily buy another
A couple of cheap shoot-through umbrellas and one silver reflective umbrella
Umbrella stands, two (NEED to buy more, anyway)
Continuous lighting (currently have at least three lights, not sure of the wattage on them and not home to look--also may have access to other continuous lighting through boss' husband who has some leftover equipment from when he was doing more photography)

The simplest setup I've seen was the screen with two speedlights in softboxes, one on the L and one on the R, both at 45-degree angles to the screen. Does that sound like a reasonable setup, or would you do something different?

 

[pixmedic]

Green screen is really easy.
U can get a free plug in for PS that let's you replace the background in minutes.
We don't use ours very often , but it's fun to play with sometimes. Just remember you lose DoF with the greenscreen digital background swap.

 

[Scatterbrained]

I rarely use green screen, but it's really not hard. You can get stand alone software that will do everything for you (I use FxHome PhotoKey Pro); from removing the green screen (even around hair and through tulle) and creating an alpha channel to dropping in a new background and creating new shadows. The thing you have to watch out for with green screen is color contamination from the green. If you get the subjects too close to the background you may end up with some green reflecting back on them. Software like Photokey can usually (but not always) get rid of it but it's better to have enough space when shooting to avoid it. As far as which background to get, there are a lot to choose from: http://www.adorama.com/searchsite/d...green+backgrounds&category=3950&sort=p_name|1
For simple headshots one of the pop up portable backgrounds would work fine, even for 3/4 shots. For full length you'd be better with a 10x12 or even 10x24. If you're just shooting one person at a time you can get something like this and just pop it open and lean it against the wall.

 

[sm4him]

Thanks, Pix and Scatter! So, it sounds like maybe the stand alone software might make it quicker and easier to process? I'm going to be all about quick and easy with this project.
EDIT: Yikes!! $300 for that software! While it looks great and might be a good choice if we end up using this much, for this project there is NO way she's gonna spend that much on the software. Photoshop Plugin, here we come!

Just headshots won't work, so we'll probably go with the 10x12, unless I can find a bigger one for pretty cheap. I doubt my boss is going to want to throw much money at this, since it's really just a "for fun" thing for the conference--although I've already convinced her that there are quite a few other uses we can make of the green screen in the future.

Scatterbrained, I loved that popup one you linked to, but the ONLY review on it basically said it won't stay up; that doesn't sound helpful in a popup green screen!! LOL

In what little reading I've done about this, I hadn't really seen anything mention that color contamination issue, but it makes sense, so thanks! Most of the material does say to get your subject as far from the background as you can, so I'd already been planning to do that.

Would using speed lights versus continuous lighting have any effect on the color contamination issue? Would one be better than the other?

Green screen is really easy.
U can get a free plug in for PS that let's you replace the background in minutes.
We don't use ours very often , but it's fun to play with sometimes. Just remember you lose DoF with the greenscreen digital background swap.

Okay, I'm having a little trouble wrapping my head around this and making sure I understand it correctly. You lose DOF with the swap? How does that happen? It seems like since you'd be swapping in a background, the DOF would simulate whatever the background photo's DOF is.
My plan was to shoot at a fairly wide aperture and sufficient focal length to get just the person in good focus, but "blur" the green background (to the extent you can really "blur" a solid background…)--do I need to tackle this differently?

 

[pixmedic]

there's no need to blur the green-screen, because you are going to digitally remove it and replace it with a picture. I dont think I can properly articulate all the technical reasoning behind the DoF issues other than you lose that "3D" kinda view when the software swaps the background. i cant find where I put the more recent green screen work we did, but i did find one we did with our kid. not a great picture, (always tough with a special needs kid) but it will show you what to expect DoF wise, as well as some other issues like hair.
the green screen is a fun little toy though, once you get the hang of it.

hair can be an issue for the software. light colored hair more so, especially if it is not combed down well. (as you can see with our kid there)
clothes that are a similar color to the green screen will obviously present a problem.

 

[tirediron]

...My plan was to shoot at a fairly wide aperture and sufficient focal length to get just the person in good focus, but "blur" the green background (to the extent you can really "blur" a solid background…)--do I need to tackle this differently?

You need to shoot with your final background in mind. If that backgroudn is sharply focused than the subject needs to be as well, otherwise you could have focus softening toward the back of the person, and then a sharp background. That will look odd. As well, make sure you plan your lighting for the new background; that is, if it has directional light, your subject needs to be lit to match that.

 

[sm4him]

there's no need to blur the green-screen, because you are going to digitally remove it and replace it with a picture. I dont think I can properly articulate all the technical reasoning behind the DoF issues other than you lose that "3D" kinda view when the software swaps the background. i cant find where I put the more recent green screen work we did, but i did find one we did with our kid. not a great picture, (always tough with a special needs kid) but it will show you what to expect DoF wise, as well as some other issues like hair.
the green screen is a fun little toy though, once you get the hang of it.

hair can be an issue for the software. light colored hair more so, especially if it is not combed down well. (as you can see with our kid there)
clothes that are a similar color to the green screen will obviously present a problem.

Ah, yeah, okay that makes sense now. I get what you're saying about the DOF; this is gonna be SO incredibly cheesy--or possibly just unspeakably awful--that a little bit of a funky DOF perspective won't matter a bit, lol!

I think the background image will have a fairly deep DOF; not actually sure what we'll be using precisely, but at least part of it will be cgi, so it would look even worse than I'm already imagining if it had a shallow DOF!

I'm really concerned about the hair aspect, because I generally really stink at processing that includes hair anyway. I'm also VERY concerned about the clothing aspect, as we won't be able to control, even a little bit, what people wear. The best we can do is probably to print a sign stating that green and similar colors will not work well.

...My plan was to shoot at a fairly wide aperture and sufficient focal length to get just the person in good focus, but "blur" the green background (to the extent you can really "blur" a solid background…)--do I need to tackle this differently?

You need to shoot with your final background in mind. If that backgroudn is sharply focused than the subject needs to be as well, otherwise you could have focus softening toward the back of the person, and then a sharp background. That will look odd. As well, make sure you plan your lighting for the new background; that is, if it has directional light, your subject needs to be lit to match that.

Oh yeah, that's a good point about the directional lighting. See I knew this was all more complicated than I want it to be!! Oddly though, as much as I think this particular project is going to be awful, I really find myself wanting to do it--just for the experience, and for things I could see us doing with this in the future.

By the way, the reason it's going to be awful, even if I manage to pull off the green screen part well, is because what she wants is a "Busnado" setting. You know, like Sharknado, only with buses and trolleys? Then the person gets dropped into that background, like they are fleeing from the busnado, I guess. Well, part of the problem is that I *don't* know--I hadn't even HEARD of Sharknado until she told me about it. The second problem is that my graphic design skills do NOT include masking buses into tornado scenes, and the third problem is that I think the whole idea is stupid.

 

[runnah]

I hate it because it never looks right. You can always tell it's a green screen because unless you are spending major time getting the lighting to match the background it's going to look weird.

What does she want the background to be? Would it be possible to go with something simple like a printed backdrop or even a large poster? Why full body shots? No one likes those unless you are a fitness model.

 

[Scatterbrained]

.........................By the way, the reason it's going to be awful, even if I manage to pull off the green screen part well, is because what she wants is a "Busnado" setting. You know, like Sharknado, only with buses and trolleys? Then the person gets dropped into that background, like they are fleeing from the busnado, I guess. Well, part of the problem is that I *don't* know--I hadn't even HEARD of Sharknado until she told me about it. The second problem is that my graphic design skills do NOT include masking buses into tornado scenes, and the third problem is that I think the whole idea is stupid.

That.......sounds........AWESOME! I love it! It sounds like some very lighthearted fun to me, assuming you can get the background image right. Time to start hitting up stock sites for cloudy skies, tornadoes, buses, dust clouds, etc.

 

[sm4him]

I hate it because it never looks right. You can always tell it's a green screen because unless you are spending major time getting the lighting to match the background it's going to look weird.

What does she want the background to be? Would it be possible to go with something simple like a printed backdrop or even a large poster? Why full body shots? No one likes those unless you are a fitness model.

Well, this is going to be purposely cheesy, so not looking "right" won't be a big problem.

See the end of my last post for what the background would be--full body shots would be needed because they will be running away from, or cowering in front of, a big tornado that is slinging buses everywhere. Seriously. I can't just make this stuff up!
But the good thing is, it's gonna be so cheesy and awful that nobody will pay much attention to anyone's "physique" in the photos!

.........................By the way, the reason it's going to be awful, even if I manage to pull off the green screen part well, is because what she wants is a "Busnado" setting. You know, like Sharknado, only with buses and trolleys? Then the person gets dropped into that background, like they are fleeing from the busnado, I guess. Well, part of the problem is that I *don't* know--I hadn't even HEARD of Sharknado until she told me about it. The second problem is that my graphic design skills do NOT include masking buses into tornado scenes, and the third problem is that I think the whole idea is stupid.

That.......sounds........AWESOME! I love it! It sounds like some very lighthearted fun to me, assuming you can get the background image right. Time to start hitting up stock sites for cloudy skies, tornadoes, buses, dust clouds, etc.

^^Ah, and therein lies the rub!! Because *I* know that I cannot, in fact, get the background right--doing that just right requires skills that I do not yet possess and don't foresee gaining in the next 5 weeks. So instead it's just gonna look…awful. I've explained in no uncertain terms to my boss that this exceeds the limits of my skill set, but I think she secretly still believes I can pull it off. And I can't.
Hey, Scatterbrained…how would you like to create a Busnado background for me??? Just for fun of course, no actual payment involved.