Green Screen Techniques

[Mist001]

I want to do some green screen stuff using real people and changing backgrounds. I've been looking at green screen videos online and the green is a very bright, vivid green. Since I want to use people, my green screen has to be quite large, so I was thinking about using bed sheets. The best that I can find are lime green bed sheets on Amazon which look quite bright in their photos but I was wondering if the green has to be this particular vivid green that I've seen online, or would a brightish green colour work? Would the lime green sheets from Amazon do the job? Here's the link:

https://www.amazon.co.uk/Plain-Fitted-C ... ref=sr_1_1

TIA.

[asik1]

green screen is not just the "green" it's the lighting.
If those sheets is all you want to spend on than deal with them. light them with a greenish light to enhance it.
and pay attention to your foreground stars wardrobe and backlight..

[Davidk]

It's called "green screen" because that's the colour that the technique was first used with. But other colours will do - a deep royal blue is another. There are 3 essential things: consistent colours, colours that normally don't occur naturally and a background colour that is a smooth surface (wrinkles, ironing creases or suedes don't work well). The latter means attention to how you hang the background sheet, and probably requires some form of weights on the bottom edges to ensure the drop is smooth.

Understand how the technique works. You are combining two images by subtracting the background colour - green or blue - from one in the process. If the background/subtracted colour exists in the (other) normal image, it's going to be subtracted too. Which would leave a result that's not satisfactory. You might use blue if the background of the normal clip is greenery, or green if the background in the normal clip is sky.

That lime green you indicated in your post link would be 'iffy'. Look at the colour chart in the Mask/chroma key options for colours that would work: the deep green or royal blue are there.

[BrianCee]

It doesn't have to be green at all these days - any fairly dark colour which is not present in the foreground figures will work -- but smooth shadowless lighting of the background is essential for a clean blend

[Mist001]

When you say any dark colour would do, does that include dark blues and shades like that? See, it's going to be easier to find background materials in those colours than it is to find bright green. The reason I'm thinking of bed sheets is A, for the size, and B, for the storage afterwards. If I get a huge board and paint it, then where am I going to keep it afterwards? Weighted sheets can be rolled up and they seem to be the way to go. I understand of course, that my subjects will be wearing contrasting clothing. No point filming them if they're going to disappear!

[BrianCee]

Yes dark blue works well providing your subjects don't have dark blue eyes

basically any colour that does not appear in the figures - and smooth shadowless background lighting will work

blue is now quite commonly used in film studios

blue screen filming.jpg (38.23 KiB) Viewed 4152 times

and also works in Videostudio

[Mist001]

I can get a range of colours which you can see on the link below. I'm tempted for the green because that seems to be the most commonly used colour according to the videos I've seen online but it was mentioned above that blue can be used, so I'm also looking at the marine blue option. Any comments?

https://www.amazon.fr/Technologie-Drap- ... ref=sr_1_4

TIA.

[pepegota]

If you want the best Green Screen software then, Green Screen Wizard is it but, it's pricey.

[Mist001]

After having a brief look at that Green Screen Wizard, it strikes me that I can do the exact same thing as that does just by using PNG files. Moving images are a bit harder though, that's why I'm looking at green screen techniques.

[Davidk]

There's a reason a deep green, usually emerald green - and a royal blue are used as the backdrop for chroma mask actions - they are rarely see au naturel. Of the colours in the image you linked, I would choose the royal blue you outlined (red box), unless the clip you want to merge with has this colour anywhere in it.

[Mist001]

I'm almost ready to go with your suggestion but what's holding me back is if someone is wearing black clothes against the royal blue, then it might not be effective. With green, there's a distinct contrast between the colours which might not work with a blue screen.

[Mist001]

I did better than bed sheets, I bought the real thing from eBay!

https://www.ebay.co.uk/itm/Toile-de-fon ... 2931652815

[Scubbie]

I would be tempted to go with the green.

The reasons have already been mentioned above, but to reiterate green is used more often as it is not a shade that is normally present in your human subject.

Make sure that the green screen is properly lit. Your subject should not cast a shadow on it if possible. Also, make sure that your subject is well lit. Both of these are mentioned above too. Read up on studio lighting techniques for the subject if you are unsure.

There are many guides available. Below is one that appears to be clear:
https://www.techsmith.com/blog/get-perf ... ing-video/

This one covers green screens better:
https://www.premiumbeat.com/blog/lighting-green-screen/

[BJC]

also have a look at this tutorial from Corel

https://learn.corel.com/projects/diy-gr ... gn=SMPRVSP


....

[Mist001]

Yeah, I saw the Corel video a while ago but they don't make pizza boxes in the sizes I'm after!