Blue screen/green screen

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ejder
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Joined: Oct 9 2004

Ok just about to take my first foray into chromakeying. I am sure that I have heard that green screens ae better than blue when it comes to DV work. Is that true? also rather than spending lots of money on the screen material, which i would have to import as it is not available here, is it possible to use a 'green' coloured material or a painted background, if so would anyone know a pantone equivalent for the colour. (or even a Dulux mix centre colour:p )
Any advice on cromakeying greatfully received.

DAVE M
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Joined: May 17 1999

green is better than blue - all sorts of colour sampling reasons that I don't understand.

not too many people would wear an item of clothing that's as green as chromakey green and green eyes are lesss common.

You might find that you can buy a tin of chromakey paint but any really saturated green would do. I've used notice boards covered in a blue velour, blue polycotten and made a green sceen 8ft high and about 30 foot across aout of hardboard and paint (rosco)

look at http://www.bristolpaint.com/ for ideas

ejder
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Joined: Oct 9 2004

Thanks Dave
I think I will pop down to the fabric shop and buy a large roll of some pretty vivid green stuff that I have seen. The link to the paint suppliers was interesting but I dread to think of the cargo cost and customs duty shipping it to here!!!!

Dave R Smith
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Joined: May 10 2005

Hi Ejder,

Even lighting with no shadows is critical. If not using a flip out chroma screen, make sure there are no creases in the cloth. Again to avoid shadows, the subject needs to stand forward of the screen, although this does mean a smaller area that they can move in.
Back lighting on subject helps reduce the green glare bounce from the screen seen on edge of subject.
If not essential avoid skin tones around edge detail - (ie long sleeved shirt easier to key) and frizzy hair is much harder to key than flat hair.
If floor is required - that's more complexity to get even lighting.

Rob James
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Joined: Jun 26 2001

A nice, livid green should do it. However, if you want a simpler way (because lighting it can be a b*gger) then you might want to have a look at this:

http://www.holdan.co.uk/datavideo/ckl100.htm

Have a go first with some locally sourced material and try to light it as evenly as possible. Light the victim(s) separately and avoid getting their shadows on the backcloth. I.e. the greater the distance between the foreground action and the backcloth the better. You might also want to have a look at this:

http://www.digitaljuice.com/djtv/segment_detail.asp?sid=78&searchid=28701

to get some ideas. It's a bit hysterical US style but possibly useful. I think they have a couple of others on the subject as well.

Please let us know how you get on.

Rob The picture is only there to keep the sound in sync

ejder
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Joined: Oct 9 2004

Thanks Dave and Rob,
I have been doing some research and understand the impotance of lighting now. Both of the links Rob supplied were very useful, I like the look of the led ring and reflective material but I think will try the budget option first (It's very difficult typing this with a kitten walking over the keyboard).
Thanks again for your help and I might even get round to posting the results. Will keep you posted. Will probably have a few more questions later as well. By the way how is the weather in the UK. really tedious here just non stop sunshine :p

Rob James
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Joined: Jun 26 2001

Glad the links were useful. The Datavideo retroreflective background and LED ring looks to be something of a bargain since the only equivalent available until recently is more than twice the price. They both use a technique originally developed by the BBC.

I was suggesting you tried the budget option first. How easy it will be to pull a good key will depend partly on the lighting and partly on what editor you are using. The latest CS3 version of Adobe Production Studio Premium includes what used to be Serious Magic Ultra 2 which is widely regarded as a good option. Otherwise, if you are using Edius it should do a good job without extras. Others will comment on their own solutions I'm sure.

Depending on what you are attempting to do, with your constant sunshine, you may well find that shooting outside will work well.

Fortunately my dogs are too small and lazy to walk over my keyboard ;)

Weather? Unremitting sunshine down here on the South Coast for the last few days...

Rob The picture is only there to keep the sound in sync

Dave R Smith
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Joined: May 10 2005
ejder wrote:
(It's very difficult typing this with a kitten walking over the keyboard).
... By the way how is the weather in the UK. really tedious here just non stop sunshine :p

aaagh. Sod the chroma - lets see a pic of the kitten on the keyboard.
Next door neighbor is currently somewhere in Bodrum area and reports it as v.hot.
Quite hot here, but too hot to work.
Which part of Turkey are you in?.. mm I think we've had this conversation before... de ja vu..

ejder
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Joined: Oct 9 2004

I must admit the light ring technology did not seem as expensive as I thought it would be. I shall be doing most of the green screen work out doors and am hoping to use reflectors to fill in the shadows. I am currently using Avid liquid 7 as my editor but I do not know how well it will cope with keying, anyone have any experience with LE 7 and keying?

Fortunately our dogs live out doors (luxury kennels of course) and don't get anywhere near my keyboard. :)

Forgot to say that I have ordered the adobe cs3 master suite so I may be learning premier but I do not know how easy a transition it would be from LE 7.

stuart621
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Joined: Oct 24 2001
Rob James wrote:
Glad the links were useful. The Datavideo retroreflective background and LED ring looks to be something of a bargain since the only equivalent available until recently is more than twice the price. They both use a technique originally developed by the BBC.

The whole idea of chromakey was first developed by the BBC, wasn't it? They called it CSO (Colour Separation Overlay) and although the original colour they chose was blue, they changed it to yellow or green as they couldn't use the Tardis on blue sets (for obvious reasons!) :)

Rob James
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Joined: Jun 26 2001

It may well have been. Alan Roberts will know the answer. Certainly it was known as CSO most of the time I was there. As for the colour, if you are using a production system with 4:4:4 or better, then you can choose any colour you like that suits the shot. With DV it's much more difficult to get a decent key. (4:2:0 PAL and 4:1:1 NTSC) I'm getting towards the edges of my expertise in this, I hope Alan will chime in.

Rob The picture is only there to keep the sound in sync

ejder
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Joined: Oct 9 2004
Dave R Smith wrote:
aaagh. Sod the chroma - lets see a pic of the kitten on the keyboard.
Next door neighbor is currently somewhere in Bodrum area and reports it as v.hot.
Quite hot here, but too hot to work.
Which part of Turkey are you in?.. mm I think we've had this conversation before... de ja vu..

Bodrum, I hope your neighbour is in to the club 18-30 scene!! It has cooled down a bit now, it's only 44 degrees celsius.:cool:
I am in Dalyan on the SW coast, I think you you mentioned in a previous post that you have been here Dave.
I might post some pics of the kitten(s) in chatter as things that meke you go ahhhhh:D
Well I am off to get my green screen material see you all later.
Al

ClaireTall
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Joined: Jan 28 2004

You seem to be going to a lot of trouble for this. Just buy a roll of Chromakey green paper

http://www.lastolite.com/paperrolls.php

and a couple of stands

http://www.speedgraphic.co.uk/prod.asp?i=11606&1=Interfit+Background+Support+Set

and £150 you have yourself a chromakey kit

I use the paper set up when we have to film whole body otherwise I use the excellent Reflecmedia set-up, bit expensive though.

http://www.reflecmedia.com/

For specialist software we use Mattenee although it seems to have disappeared.

Studio with green screen for hire near Gatwick Airport.
Kit hire facilities on site.
excelsiorstudios.co.uk

ejder
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Joined: Oct 9 2004

Thanks for those links Claire I notice that lastolite have a distributor in Turkey but they don't do the paper unfortunately.

Driving to the shop to buy a roll of material is a lot less trouble than trying to import items from abroad, believe me.

Already have some reflectors and a support (made by the local blacksmith for £20, asked him to make it this morning and picked it up this afternoon, not bad eh) The shop had sold out of the green material, I think someone else in Turkey is trying out keying as well, I can't think why else anyone would have bought it unless they are colour blind:D

Dave R Smith
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Joined: May 10 2005
ejder wrote:
The shop had sold out of the green material, I think someone else in Turkey is trying out keying as well, I can't think why else anyone would have bought it unless they are colour blind:D

Snookered?

ejder
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Joined: Oct 9 2004

Now you are just trying to be cueT aren't you, now give it a 'break' :p

Dave R Smith
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Joined: May 10 2005

I took ias read, you'd give me black looks for my foul shot.
Unlike you, I'm now going for a nap.

Christian Lett
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Joined: Apr 26 1999

Hi, I have it on pretty good authority that generally speaking, shooting greenscreen on DV cameras gives no advantage over bluescreen dispite the green channel of video being higher resolution than the colour channels. It's down to the way the keyer works, using all channels to compare the differences in pixels. (the one keyer that does use the luminance channel to its advantage is DV Matte Pro from DV Garage.

For white skin tones, blue is better because the spill isn't so harsh and it's a more complimentary colour to the skin tone than is green.

From my own experiences, keying out someone from in front of a greenscreen is still a nightmare to do well, and it usually involves some rotoscoping and various different mattes combined. Pulling a decent key in an NLE will also prove very difficult. If you've got CS3 on the way, I'd learn Keylight in After Effects, or even better use the bundled Ultra Keyer program, which by all accounts gives great results.

Christian

Christian Lett After Effects and Maya Artist www.quarterlightpictures.com

ejder
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Joined: Oct 9 2004

Thanks Christian, Ihave the green material now so I will stick with that at the moment and see what results I get. I will have to get to grips with after effects and this may be the ideal opportunity. Another steep learning curve pending I am sure.

Will post back with an update (eventually)

AMB Productions
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Joined: Sep 9 2007

I used blue, and had to key out a few different blues (using after effects), still wasnt the best.

I know that you can get blue or green colorama rolls of paper, thats about £50 a massive roll.

AMB Productions - Northwest Wedding Videographer

http://www.ambproductions.co.uk

ClaireTall
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Joined: Jan 28 2004

The way to avoid all the work in post is to use the Reflecmedia system, the green is the same throughout, one click and it's done, perfectly. We actually did a job for Sony (name drop, name drop) where they needed hair in the wind keyed out, worked a treat.

Studio with green screen for hire near Gatwick Airport.
Kit hire facilities on site.
excelsiorstudios.co.uk

AMB Productions
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Joined: Sep 9 2007

Sounds good! expensive tho?

AMB Productions - Northwest Wedding Videographer

http://www.ambproductions.co.uk

Dave R Smith
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Joined: May 10 2005

Yes expensive for one off (though does save time in post production) I have yet to find a company that hires them out.

Rob James
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Joined: Jun 26 2001

Fora cheaper alternative, roughly half the price, have a look here:

http://www.holdan.co.uk/datavideo/ckl100.htm

Rob The picture is only there to keep the sound in sync

Dave R Smith
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Joined: May 10 2005

That is good.
Reflecmedia is around £1250-1500 when looked in the past.
I have previously had impression Holdan were agents for reflecmedia, so just phoned them.. it is different co's gear (but similar).
No larger cloths, but can buy second cloth same size for £299.
I asked if you can stand on it - he says yes, but I bet it voids any g'tee as I think they are glass beads stitched on.. so a tad delicate.

Christian Lett
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Joined: Apr 26 1999

Claire, what were you shooting on using the Reflecmedia kit, just out of interest? DV/HDV (4:2:0) or Beta (4:2:2). As that will make a difference too. Thanks for mentioning the Reflecmedia system though, and thanks also to Rob for pointing me in the direction of the Holdan kit, which looks great for £500.

C

Christian Lett After Effects and Maya Artist www.quarterlightpictures.com

Rob James
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Joined: Jun 26 2001

Christian, if you do decide to go for it I'd be very interested in what you think. If you didn't live so far away I'd have suggested a shared purchase. As it is, I'm sorely tempted to go for it myself.

Rob The picture is only there to keep the sound in sync

ClaireTall
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Joined: Jan 28 2004
Dave R Smith wrote:
Yes expensive for one off (though does save time in post production) I have yet to find a company that hires them out.

We don't hire ours out because it is so delicate and a different adapter ring is required for different lenses.

I shot the Sony job on DVCAM using a DSR450 it was for an intranet so didn't need to be Digibeta quality.

I know it is rumoured that there can be difficulties shooting green screen on HDV or XDCAMHD but I've shot on all different formats with both paper green screen and Reflecmedia and not had any problems, maybe modern software is better at keying out.

When shooting on paper green screen because of size I take a MacBookPro and do a test after lighting.

Studio with green screen for hire near Gatwick Airport.
Kit hire facilities on site.
excelsiorstudios.co.uk

Chrome
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Joined: May 26 1999
ClaireTall wrote:
I know it is rumoured that there can be difficulties shooting green screen on HDV or XDCAMHD

No tin my experience...

Like Claire I use the reflecmedia system with XDCAM HD and have had no real problems with it, shooting over 14 hour of interviews for the programme I'm currently making.
Like Claire I think that it's a very adaptable system.

Alan Roberts
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Popular conception - 4:2:0 is not good enough for keying.

It depends on what you're doing with the output. As far as broadcasters are concerned, it's true, because they expect their output to be of the highest possible quality and routinely use top grade monitoring to check. Also, their output is likely to be examined by co-producers. At the lower levels, it's fine, because the output is always going to end up going through a 4:2:0 system for final coding (e.g. MPEG).

The same also applies to recordings made with significant data compression. Even with 4:2:2 coding, the results can be poor if the compression is excessive, because the decompression artefacts can be quite coarse when examined frame by frame, and perturb the contours that keying demands.

So, when I talk to broadcasters, 4:2:0 cameras like DV, DVCAM, HDV etc are also-rans for keying, but for non-broadcasters, they can be just fine.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

jlove
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Joined: Nov 23 2007

First of, let me introduce myself as I'm new here. Name is Jay, and my set up includes a JVC GR dv900u, a Sony DCR VX1000, and I'm editing using Pinnacle Studio v9 plus, with my interface being a pinnacle av/dv 500 pci card.
Just wanted to share with you how I made my own green screen for next to nothing.Went to the local hardware store and bought a few 12 foot lengths of pvc plumbing tube, a cpl of "elbows"(the ones bent in a "L" shape), and a cpl "T" connectors,all of the same diameter. Next stop was the local fabric store where I found some very green canvas on sale and bought a piece 6' wide by 8' high. I cut the pvc tubing into two 7' lengths, and used the 2 5' off cuts as the cross(horizontal bars), which incedentaly, when I added the "T" connectors to the bottom of the 7' side(vertical) bars, fit the 6' accross canvas perfectly. So the "T" bars hold the bottom cross bar in place, and the elbows hold the top one. I had my wife sew the top fo the canvas so the crossbar could slide through, hung it, and voila!! Use a couple of microphone stands slid into the bottom of the vertical sidebars as legs. I have found that lighting is the key to good green screen effects. It has to be very even on the screen itself, so i use reflected light from some lights reflected off of white bristol board to get the screen lit with no shaddows. Be sure to light the subject sepperately with a key light, and a diffused fill light, keeping aware to light them for the scene they will be keyed into. If your cam has zebra stripe function, it will be a huge bonus for green screen effect as it will identify areas of over exposure which will make it imposable to get a believable effect. The pinnacle studio chroma key effect works awesomely, allowing you to match the key color by simply clicking on it. I will post a pic of my homemade green screen in the comming days. Cheers, Jay.

branny
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Joined: Nov 6 2001

Hi Jay and welcome to the forum.
This sounds very effective. A taut backdrop is a big help in providing clear keying. Pop the pics up next time you're here.

Do not follow, I may not lead. Do not lead . . . I may not follow.

Alan Roberts
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Folds and creases are death to keying, keep the material as taut as is reasonable. And don't forget that you can have the cloth on the floor as well, so that you can key feet. It's usual to have a long drop that spreads onto the floor. Keep outdoor shoes off it, and keep tripods off it as well, because the feet will snag the cloth.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Dave R Smith
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Joined: May 10 2005

I've just rec'd tv-bay magazine (Europe issue 015) which has a couple of articles on Chroma keying.

Simon Tv-bay
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Joined: Jan 8 2008

Take a look at tv-bay magazine issues 15 and 16 for quite an in depth guide to chromakey techniques and equipment from beginners to advanced - if you need a copy just let me know

http://www.tv-bay.com
Subscribe to the tv-bay monthly broadcast guide http://www.tv-bay.com/subscribe

Dave R Smith
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Simon Tv-bay wrote:
Take a look at tv-bay magazine issues 15 and 16 for quite an in depth guide to chromakey techniques and equipment from beginners to advanced - if you need a copy just let me know

Where's my commission ;)

NigelW
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Joined: Mar 2 2008

Hello Edjer
I'm heading your way 19 April for one week ANZAC pilgramage. Is there anything I can bring you from Ol' Blighty (within reason) that might help you out down there. We could meet up in Istanbul for a coupla beers if your'e up for it.
Lemme know.
Best N

ejder
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Joined: Oct 9 2004

Hi Nigel,

Thanks for the offer.A couple of z1's and a reflecmedia system would be nice:D

What a shame, I shall be on my travels that week and no where near Istanbul I am afraid. Maybe next years Anzac day. :cool:

Cheers

Alan

Leepy
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Joined: Jun 2 2008

Hello there

I've recently stopped shooting my shorts on 16mm film and have moved over to digital (mini DV). I couldn't believe the power of digital editing/shooting. I use Premiere Elements on my home PC. I got so excited when I realised that Premiere Elements could do blue screen that I embarked on my first special effects film. I thought: what's the simplest monster I can create and manipulate with blue screen? I used blue screen for the puppets and green screen for the actor. The short is called Doodlebug and you can see it here:

http://www.virginmediashorts.com/film/1543551325

The process took ten months; I'm very proud what we managed to achieve, at home(!) on such a low budget (fifty pounds).

Hope you enjoy!

Lee

Alan Roberts
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Joined: May 3 1999

Lee, there's no need to do multiple postings here. Plus, we have a place specially for telling us to watch your video, post about it there.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Leepy
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Joined: Jun 2 2008

Sorry Alan - got a bit carried away. I'll re-post there.

Best

Leepy

simond83
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Joined: Sep 5 1999

I've just taken delivery of some of the Blue & Green screen fabric from Bristol Paints. It's top quality stuff and works a treat :-)

Leepy
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Joined: Jun 2 2008

Have FUN!!!

Leepy