DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   What Happens in Vegas... (https://www.dvinfo.net/forum/what-happens-vegas/)
-   -   green screen backgrounds (https://www.dvinfo.net/forum/what-happens-vegas/192029-green-screen-backgrounds.html)

Renton Maclachlan April 13th, 2009 03:57 AM

green screen backgrounds
 
I have just produced and posted a 10 min youtube clip on a political issue here in NZ. I did it with my green screen and the new GS lighting setup I've just made worked brilliantly. Smooth even lighting making for a great key with no spill at all. I asked a couple of weeks ago about backgrounds, and eventually found a photoshop tutorial that tells how to create a studio background. I followed that and it came out great.

However I've been thinking that it would be nice to keyframe this somehow so you start with one colour and end with another. Effectively the Photoshop creation is a still photo stretched behind video, and you can't access the variables in the image to keyframe them - I don't think. I tried removing all colour from the image, then doing a partially transparent Vegas media generator colour gradient over it to put colour back in. This I can keyframe, but the colour doesn't look as good as in the Photoshop image.

My aim is to have a very subtle - virtually unnoticable - changing of the background to add a bit of subtle dynamic into a presentation of this sort.

Anyone have any other suggestions how to achieve this aim?

Mike Kujbida April 13th, 2009 05:21 AM

You could do this in Photoshop by changing the colour and then saving several different versions of the image.
Bring these into Vegas and do slow dissolves from one to the next.

However, this can be done and keyframed in Vegas as well.
Take a look at Edward Troxel's newsletters, specifically Vol. 1 #11 (Doing a Color Pass) and Vol. 2 #10 (Color Pass Reprised - Passing Multiple Colors) for some ideas to get you started.

Renton Maclachlan April 13th, 2009 02:27 PM

Thanks Mike, I'll check Edward's newsletters out...

Douglas Spotted Eagle April 13th, 2009 11:18 PM

Quote:

Originally Posted by Renton Maclachlan (Post 1086731)
I have just produced and posted a 10 min youtube clip on a political issue here in NZ. I did it with my green screen and the new GS lighting setup I've just made worked brilliantly. Smooth even lighting making for a great key with no spill at all. I asked a couple of weeks ago about backgrounds, and eventually found a photoshop tutorial that tells how to create a studio background. I followed that and it came out great.

However I've been thinking that it would be nice to keyframe this somehow so you start with one colour and end with another. Effectively the Photoshop creation is a still photo stretched behind video, and you can't access the variables in the image to keyframe them - I don't think. I tried removing all colour from the image, then doing a partially transparent Vegas media generator colour gradient over it to put colour back in. This I can keyframe, but the colour doesn't look as good as in the Photoshop image.

My aim is to have a very subtle - virtually unnoticable - changing of the background to add a bit of subtle dynamic into a presentation of this sort.

Anyone have any other suggestions how to achieve this aim?


You could easily create a fake spotlight by masking generated media, and slowly (or quickly) keyframe light movement. There is a tutorial on the VASST site about generating spotlights.

Ken Campbell April 14th, 2009 01:10 AM

If you use Vegas you can create very convincing animated backgrounds without leaving Vegas, using Photoshop or After Effects, etc.

If you go to all the trouble of keying against a greenscreen, why settle for a solid color? I would just shoot against a colored backdrop. Since you now have a great key, why not put a few meaningful photos in the background and animate them panning or zooming? Or you could put a related video behind them. I sometimes use the Digital Juice Jumpbacks for animated backgrounds and then cut mattes out of them to put photos or video behind. Then put occasional text and lower thirds over and you end up with multilayered video that has visual punch.

Renton Maclachlan April 14th, 2009 02:46 AM

Quote:

Originally Posted by Ken Campbell (Post 1090594)
If you use Vegas you can create very convincing animated backgrounds without leaving Vegas, using Photoshop or After Effects, etc.

If you go to all the trouble of keying against a greenscreen, why settle for a solid color? I would just shoot against a colored backdrop. Since you now have a great key, why not put a few meaningful photos in the background and animate them panning or zooming? Or you could put a related video behind them. I sometimes use the Digital Juice Jumpbacks for animated backgrounds and then cut mattes out of them to put photos or video behind. Then put occasional text and lower thirds over and you end up with multilayered video that has visual punch.

Thanks Ken. I do it against a greenscreen because then I can use any background I want and am not limited to what is there. The photoshop background I used was not solid colour but a cloud type of arrangement which turned out pretty good I thought, even though it was straight off a tutorial.

Then of course, the question of backgrounds raises the issue of whether you want it simple or complex, whether or not what you put there enhances or distracts from the primary focus, in my case a talking head and the content it is communicating. It seems to me that any technical effect used, no matter what it is - background, lighting, added text, crossfades, etc, needs to be 'transparent', meaning that in normal viewing, people don't see it. If they see it - because it draws attention to itself - then the effect has failed in its purpose. It's like the effect of using a cooky to throw shadows. They add a subtle something to the composition which you don't even see till you take them away.

In the piece I'm referring to I used three cameras with varying levels of zoom. The first third was a wider shot, the second medium, and the third quite close - the theory being to heighten the intensity of delivery. A friend who watched it 'critically' - because I asked him to, noticed the first and third zoom levels but missed the second one. That quite pleased me. (I hid the changes of zoom behind screens of text that were being read, so there was no transition that could be seen.

I'm feeling my way in this but think at this stage that simplicity - not necessarily
'plainness' (that is why I did a photoshop backdrop) - enhances better than complexity does.

Since it has been 'published' I've had numerous very positive comments about it - which is nice - so it seems at a technical level I succeeded. Whether its content will have a political effect is another matter.

Renton Maclachlan April 14th, 2009 03:12 AM

I've just played around with using my Photoshop image with colour removed, with a media generated solid colour over it with the alpha set to about 120, and keyframed from one colour at the beginning and another at the end. This gets the sort of effect I'm after.

The only question now is, what colours should be used at the beginning and the end, to go from 'low intensity' to 'high intensity' - or at least to increase intensity as the clip progresses.

Ian Stark April 15th, 2009 03:08 AM

To add to Spot's great suggestion about a spotlight, another way to create the effect is using the Bump Map filter in Vegas.

Here's a post from a while back that covers how: http://www.dvinfo.net/conf/what-happ...g-effects.html

The video mentioned in the post is no longer up at the address shown but it's on YouTube if you're interested YouTube - 'Spaceship' by Craydle

I often use this effect in corporate videos to create an atmosphere or to focus attention on something. It's especially useful when the background is not very interesting and it's dead easy (no masks required!). If used subtly on a background it can be animated to slowly move across the image giving a pleasing result.

Might not necessarily be what you're after for your production, Renton, and it looks like you've got yours sorted now, but I thought anyone else reading this thread might appreciate another idea.

Cheers,

Ian . . .


All times are GMT -6. The time now is 06:08 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network