Need Chroma Key Tips

will-3 wrote on 3/21/2015, 4:47 PM

Please ignore my previous post on Chroma Key. The basic problem of the blue halo has been solved.

Here is where I need help now.

I'm running Vegas 12 and chroma keying a short green screen clip of a talking head to appear in front of a still image.

I'm getting a very light green tint around the subjects arms. Here is the procedure I'm using in Vegas 12

1 - Add Chroma Blur fx to clip
2 - Select Medium Blur
3 - Add Chroma Keyer fx to clip
4 - De-select the Chroma Keyer
5 - Select the Color Picker fx
6 - Click on the green background around the subject
7 - Turn back on the Chroma Keyer fx
8 - Check the Show mask only check box
9 - Drag the Low Threshold until the subject is completely white
10 - Drag the High Threshold until the background looks proper
11 - Adjust the Blur amount to... what?
12 - Uncheck the Show Mask Only check box
And I'm done

But I get that very light greenish tint around the subjects arms (mainly)

- I've tried tweaking the High Threshold to get rid of that very small green tent along the arms of the subject but then then some of the other edges begin to look ragged... or with a little bit of color separated from the subjects outline.

- Adjusting the Chroma key Blur seems to help mitigate the green tint along the arms but then the thing starts to look a little fuzzy along the edges.

Can you guys give me some tips?

Is there another fx plugin or tool that can be added on to Vegas to do a better job... or what?

Thanks for any help.

Comments

larry-peter wrote on 3/21/2015, 5:08 PM

I haven't used Vegas' Chromakeyer in a decade, (Keylight in After Effects, or Boris) but I'm pretty sure the Chromakey blur is an alpha blur - to smooth out the aliasing in the matte. If it's set too wide it will blur your subject edges .

Since Vegas doesn't have a designated spill supression plug in, I'd try setting the CK Blur to your liking and attacking the green tint on the arms with the Secondary Color Corrector. If the CK blur is set wide enough that you're seeing the actual green background, you'll either have to compromise the blur settings or try to dial in the fringe to look better with your background clip.

Edit: The Boris Continuum keyer and matte tools are the best I've seen for Vegas plugins. But now that Fusion is free, if you don't mind learning node-based compositing and a new workflow, it might be the best chromakeyer around.

larry-peter wrote on 3/21/2015, 5:21 PM

I just noticed you were also using a Chroma Blur FX before the keyer. I haven't had to use that technique since the SD days. Look at reducing that also, even to only blurring the green channel.

farss wrote on 3/21/2015, 7:34 PM

One thing I've found using Vegas's inbuilt keyer is to start with the appropriate preset and then tweak that. If you use a sample from the actual screen you can end up with values that have too broad choma values. Start with a garbage matte, select the green screen preset and tweak the luma in/out points with the "show mask only" option on.

Needless to say, 90% of getting a great key depends on what's in front of the camera and once that's great using a camera with 4:2:2 chroma sampling helps.

Bob.

deusx wrote on 3/22/2015, 6:29 AM

Download Fusion 7, it's free now.

You aren't going to find anything better even if you pay for it. It's not worth trying to do it in Vegas when you have much better tools for free now. You get Fusion's keyers and you get Primatte too. Primatte alone used to be $500 just a few years back.

https://www.blackmagicdesign.com/products/fusion/compare

It's ridiculous what they are giving away.

will-3 wrote on 3/23/2015, 12:10 PM

Thanks guys.

Aton12 - Is this the Boris product you suggested...
http://www.borisfx.com/units/Key-Blend.php

Bob - Your suggestion seems to have worked. Thanks!

Desux & Atom 12 - I've downloaded Fusion but have Questions:

1 - Why are they giving it away? Trying to get more people hooked on it so they will buy the upgrades?

2 - Can you install the free download on more than one computer?

Thanks for the help folks.

larry-peter wrote on 3/23/2015, 12:50 PM

Will, I am using the Continuum Complete package, but I think this keying module has all the plugins I use for greenscreen. The LightWrap plug they refer to is a custom compositing mode that can be used in Vegas and really helps the key edges.

As to why they're giving Fusion away - seems to be part of Blackmagic's paradigm now. There are some limitations to the free version vs. paid, just like with DaVinci, but both are extremely usable free versions (although both have a substantial learning curve).

will-3 wrote on 3/23/2015, 5:35 PM

Queston: When you use the Boris Chroma Key plugin for Vegas... do you stay in the Vegas environment and work flow?

If so I'm probably willing to spend the $300 to buy it vs spending maybe one or a few days learning a completely new system.

It's tempting because I enjoy learning new stuff... but time is a rare commodity right now.

larry-peter wrote on 3/23/2015, 7:31 PM

Yes, when I use Boris' Chromakeyer I do everything in Vegas. Generally I just need the Chromakeyer plugin and Lightwrap compositing mode on the foreground, but if there is flyaway hair that's problematic, I'll add the Matte Cleanup - usually just for a tiny bit of blur. I don't use the matte chokers unless I've really screwed up my lighting.

Although for time's sake I don't use it much, the Primatte keyer in Fusion is incredible. I was able to discern individual hairs on a woman's head from a greenscreen shot in 8 bit AVCHD. Couldn't get close to that result with any other keyer I have.

will-3 wrote on 3/23/2015, 8:00 PM

Well we have a Sony NXR NX5U as our main cam and if I am not mistaken the quantization on that is 8 bits... is that what you are talking about when you say "8 bit AVCHD" ?

And, do you know if they have improved on that quantization for AVCHD?

I'm doing a seperate post on the NXR NX57 cam and AVCHD issues we should be aware of.

thanks.

CJB wrote on 3/23/2015, 11:38 PM

Before I'd spend $300 for Boris chroma key unit that money might be better spend on HitFilm 3 which on sale can be had for the same money. The Chroma key capability in Hitfilm is far better (IMO) than the Boris (I have both). And you get so much more along with it. The particle generator etc.

Honestly almost any aftermarket plugin is better than what comes with Vegas. NewBlue's chromakey pro is pretty decent and a cheaper alternative than Boris.

As always, my $0.02

will-3 wrote on 3/25/2015, 12:10 PM

Well HitFilm is $300 it seems and I can determine which NewBlueFx product is the chroma key product.

I understand Boris may have a sale during NAB week and maybe the others will as well.

Does the HitFilm $300 package include more fx than the Boras Chroma Key product?

Thanks for any other comments.

monoparadox wrote on 3/25/2015, 2:44 PM

In general, as plugins in Vegas, Boris BCC offers much more control over settings. Of course, that means a higher learning curve. That said, Hitfilms chromakey plugin offers a lot more control than most other HitFilm plugins and is very capable.

--tom

CJB wrote on 3/25/2015, 4:48 PM

IMO Hitfilm greenscreen is better than the Boris plug for Vegas. Plus you get a bunch more effects with it. I have both greenscreen plugs. Boris is one of the better plugs, but exporting to Hitfilm and using their greenscreen and compositor is more intuitive (and I believe more controllable then a plug with Vegas's fiddly compositing.

SWS wrote on 3/25/2015, 8:01 PM

I have loved the Boris key plugins, they are awesome...but I did run into a situation with a well lit key that for some reason I just couldn't get clean with the Boris filters, I'm sure it was me but I had worked with similar shots before and they keyed great with Boris...that said, I figured I'd try Hitfilm and at first crack it nailed it...so moral of the story for me, is have 'em both in your toolbox.

will-3 wrote on 3/26/2015, 9:57 AM

Well I just noticed that the "NewBlueFx Chroma Key plugin" comes with Vegas Pro 13.

Question 1: Is there a difference in that and the "NewBlue's Chroma Key Pro" ?

Question 2: How much to upgrade from Vegas Pro 13 to Vegas Pro 13 Suite?

Question 3: You get HitFilm 3 Pro in the Suite along with some other stuff so that seems like a better deal than just buying HitFilm direct... right?

Thanks for the help folks !

monoparadox wrote on 3/26/2015, 12:41 PM

They had a $250 upgrade deal a month or so ago. Call customer service and beg -- from all the offers I'm getting from software companies these days they have to be pretty hungry.

--tom