Is my green screen really that bad?

YorVeX

Member
After hours of trying without any success I am desperate enough to doubt either my sanity or my eyesight - maybe I have a color blindness I didn't know about yet?

Please tell me, is this really such an extremely bad green screen (lighting) as OBS says it is? Because it is simply impossible to key it out without also keying out part of myself.

From a purely subjective perspective I can check 30 OBS chroma keying tutorials and in more than half of them the green used looks worse than mine (wrinkles, shadows, lighting in certain areas differ a lot). Yet these people just crank the "Similarity" up and at some point the background is gone and they are still there.

When I do this, I already start to lose pixels of myself while parts of the green background are still there (mostly in the bottom corners, but also a bit at the left edge).

Away from the subjective perspective, is there something objectively wrong with my green screen?

I am using 2 Elgato Key Lights left and right in front of me and an Elgato green screen behind me. They are simply pointed at me and at the green screen behind me. In the past I had success with pointing them at the walls to the left and right of me instead, putting their brightness up to 70-80%. But this heats up the room by 1°C per hour. Therefore I'd really like to avoid this, also thinking that hundreds of streamers manage to chroma key with the more simple setup I am trying now...

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thewitt

Member
Your lighting is making your green screen light in the top middle and dark in the bottom corners - as well as medium green in the top corners.

You chair and your lower corners are going to be a close match... so if you dial in the lower corners your chair will disappear.

Lighting is the key to a proper green screen. The "color" needs to be as close to the same corner to corner as possible.

I have better success with softlight boxes than LEDs as I don't get any hotspots on the screen. I put them high to my left and right and point them across the screen so the left one lights the right side and vs vs.

I use a different light on the subject.

It's all about the lighting...
 

YorVeX

Member
First of all, thanks for taking the time to read my post and write this indeed very good advice!

I know how important lighting is and I am able to achieve better/more even lighting on my green screen with more light sources (or indirect light against the wall from the Key Lights when set to 70-80%) and I did in the past, it's just that with this the room gets so hot I need to run the A/C with 10°C outside temperature or stream at 28°C after a few hours (which is well outside of my comfortable temperature).

And then I searched around and just wondered why my green screen is so extremely bad that it's impossible to make it work with OBS while these are working fine (at least good enough):
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Like, is my green screen really that bad compared to these examples?

Yes, my green screen is not evenly lit, but their's isn't either and it's working for them. And that is what really is my point. Poor little YorVeX only wants what all the other kids have :P
 

FerretBomb

Active Member
Yes, my green screen is not evenly lit, but their's isn't either and it's working for them. And that is what really is my point. Poor little YorVeX only wants what all the other kids have :P
They likely have spent a good bit of time dialling in their exact key color value, de-bleed, and similarity values.
One thing you can try is running multiple chromakey filters. One for the high, one for the low.

But also, notice that almost ALL of your examples are wearing BRIGHT shirts, that stand out strongly from their backdrops, with a SHARP edge, allowing a looser key. Your chair is black, and the dark part of your screen is VERY close in value due to the poor lighting. You'll need an INCREDIBLY tight key to separate the two, and likely still will get bleed.

Try grabbing an LED light-bar/strip and set it on the ground in front of your screen, pointed up and angled toward it. May help to at least somewhat more properly light your screen. That or get rid of your chair, and follow the above examples and wear a sharply contrasting shirt.
 

YorVeX

Member
Sorry if having the chair in the picture caused confusion by indicating there would be any problem with it. In fact the chair has never been a problem, not even when nothing else really worked or similarity values were really high, it is actually the last thing that disappears from the keying.

I wear a white hat on stream and this is the first thing to be removed from the background while the bottom corners are still there.

They likely have spent a good bit of time dialling in their exact key color value

I tried it all, picking colors from the center, from the lower area, adjusting the color manually a bit afterwards...
I would never get the idea to try keying with the standard green, this will remove myself almost before my background is gone :P

That or get rid of your chair, and follow the above examples and wear a sharply contrasting shirt.

Before I start limiting the shirts I can wear on stream (except for green shirts obviously) or have to readjust the green screen every time according to what I wear I will rather just accept to run the A/C all the time even when it's cold outside.

Try grabbing an LED light-bar/strip and set it on the ground in front of your screen, pointed up and angled toward it

That's a really good hint. With my old desk I had a LED strip under the desk and now that I got a new desk I haven't installed this again yet. It was also lighting the lower part of the green screen a bit, but obviously I have underestimated the importance of that. Now that I have put it back in place I am finally getting somewhere.
 

YorVeX

Member
As I said, my whole point is not that I don't know how to set up the lighting up to levels of almost perfection. My point was rather that it seems to work for others without this perfection, they even seem to get away with worse lighting than I still have right now and I just can't replicate this. But maybe this is where I was wrong, maybe it only works for them when they limit what they're wearing?

With my setup as it was before I swapped the desk for a new one, there were no glitches in the green screen, I could wear whatever I want, black, white, including shirts that had green elements on them:
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I did this by having the Key Lights at the back of the desk in the left and right corners, having them pointed at the walls to the left and right of me. The walls and acoustic foam panels are white, so the light bounces off very well and indirectly lights me and the green screen evenly.

When I finished this lighting setup I was really happy. You can still see some green edges here and there, but most of the time I am in a scene with a smaller cam where this is not visible at all so I was OK with that.

That was in summer when the A/C was running anyway. But with winter came the disappointment. The picture here is from winter and since I always got my live room temp shown in the stream you can see I was at 25.6°C, with an outside temp of 5°C. The room usually sits at 22.5°C when I start to stream and that picture was taken one and a half hour into the stream. From that point the temperature climb rate lowers, but it's still climbing until 28°C or probably higher, if I wouldn't give up before.

Since I got lots of equipment in the room I thought it's the heat coming from the PC or the monitors, but when I did a test stream (without being live) where the only thing I changed is that I ran the Key Lights at 20% instead of 80% the room didn't heat up nearly as much and a 6 hour stream would be possible without sitting in a sauna.

To run them at 20% though I would have to point them at me directly and this is where my journey began. I thought "this is how >90% of other streamers do it so why shouldn't it work?" but apparently I was wrong...
 

lofihap

Member
When it comes to lighting - the best thing you can do is make the room black. And just turn on the key lights. Keep adjust the brightness & angle until the green screen is evenly lit. You also want more space between you and the green screen, so you don't cast a shadow.
 
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