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Rendering green screen too much with keylight?

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Vincent Strader
Rendering green screen too much with keylight?
on Feb 22, 2010 at 8:28:02 pm

Working with AE Keylight for the first time. I will be tomorrow that is.

Here's what I wondered. I import my source against my green screen. Key it. Once I key it I render it out to a QT file to import into FCP7.

Work with it on the timeline there, then render it out again to the finished qt movie.

Is that too many rendering steps? Will it degrade too much if I start out with HDV? Or do I do all the editing of the program inside of FCP first, render it out in one solid time line, working with the key inside of AE using Keylight?

Just wondering about doing too many renders, or not enough.

Newbie,
Vinnie


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Michael Szalapski
Re: Rendering green screen too much with keylight?
on Feb 22, 2010 at 9:16:12 pm

If you're using a lossless file format between the programs it won't matter how many renders you do. In many cases, I would do the editing first then do the keying in AE. But it depends on your show. If only a few bits are on greenscreen, it might behoove you to only do those bits in AE. If you're using AE to color correct, add graphics and key throughout most of the show, I would do the edit and render the whole thing out to use in AE.

I have several little warning flags to throw up. HDV footage is about the worst possible choice for keying. There is not enough color resolution there. See this page for more info.
Even if you have no choice and you have to shoot in HDV, you do not want to work with the HDV acquisition codec in AE. Here's why from Dave LaRonde:
Dave's Stock Answer #1:

If the footage you imported into AE is any kind of the following -- footage in an HDV acquisition codec, MPEG1, MPEG2, mp4, m2t, H.261 or H.264

-- you need to convert it to a different codec.

These kinds of footage use temporal, or interframe compression. They have keyframes at regular intervals, containing complete frame information.

However, the frames in between do NOT have complete information. Interframe codecs toss out duplicated information.

In order to maintain peak rendering efficiency, AE needs complete information for each and every frame. But because these kinds of footage

contain only partial information, AE freaks out, resulting in a wide variety of problems.
So whether you're just doing clips or the entire show in AE, render it into a nice Quicktime with the PNG codec or something else nice for AE to play with.

Also there are some resources for pulling a decent key even with terrible HDV crap. Keep in mind that a good key is rarely - if ever - achieved by a one-step process. Usually it's a combination of filters on several copies of footage all composited together.
Here's a thread on the COW about getting a better Keylight key.
Here's a tutorial on that goes into some depth.

Actually, there are a bunch of keying tutorials here at the COW too that I would highly recommend like this one.

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.


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Dave LaRonde
Re: Rendering green screen too much with keylight?
on Feb 22, 2010 at 9:41:25 pm

[Vincent Strader] "I import my source against my green screen. Key it. Once I key it I render it out to a QT file to import into FCP7."

What is it with FCP guys?

Why would you want to go to the trouble of rendering out an alpha-channel movie when you could do THE WHOLE SHOT -- foreground and background -- in AE, then render in the codec of your FCP edit timeline. Oh, wait... if you using some form of HDV, you'd want to render in ProRes 422, the codec in which you should have captured the video in the first place.

By doing the entire shot in AE, you can do tricks that are really tough, if not impossible to pull off in FCP. You can color correct foreground and background to they match. You can add fake shadows, fake highlights and light wrap to make the subject look like it's really in the scene.

I'm an FCP guy myself, and I don't care what anybody says about the program: it's simply an editing app with mere delusions of being able to do effects and compositing. AE's the real deal. So you might want to take advantage of it.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Vincent Strader
Re: Rendering green screen too much with keylight?
on Feb 24, 2010 at 4:36:33 pm

Thanks. I'm not an FCP guy. I've been forced into it where I work. I had a Discreet Edit a few years back and was happy on a Windows platform. I go away for vacation, and come back to an Apple system I have to learn. Then pile on how hard it is to get anything (budgetwise) where I work, years go by, and I finally get this huge CS4 package (before I only had FCP3 to work with).

You said do it all in AE. I'm not sure what you mean. I get that HDV is awful now, and that I need to take it to a QT file first. Read both posts, thank you both. But I still don't follow what Mr. LaRonde said,

here:
"...when you could do THE WHOLE SHOT -- foreground and background -- in AE, then render in the codec of your FCP edit timeline."

and

"By doing the entire shot in AE, you can do tricks that are really tough, if not impossible to pull off in FCP."

How do I do anything in AE first? I still have to tape it with the camera in SD or HDV and import it into one of the 2 programs.

I've already done what I've done (taped in HDV), but I'd like to keep all of what you say in mind for future projects.

Thanks,
Vinnie



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Dave LaRonde
Re: Rendering green screen too much with keylight?
on Feb 24, 2010 at 5:05:42 pm

Gawd, I don't EVER want to be in your position. I feel for you.

Did your workplace totally abandon FCP when you got CS4? Is this CS4 on a Mac or a Windows box? And it sounds like the bosses said, "Okay, here's Adobe Creative Suite 4 for you. Learn it by next week."... or something like that.

If that's the case -- and you're on a deadline -- I recommend doing the keying job in Premiere. I recommend learning how to capture your HDV video in a different type of codec. HDV sucks when it comes to multigenerational work. You stand a MUCH better chance of being able to dope out how Premiere works. Save the fancy stuff for later.

After Effects doesn't work ANYTHING like an editing application because it does totally different things from an editing application. As you make the transition from FCP to Premiere, you'll have to learn AE along the way. It is NOT an intuitive thing. You will NOT be able to use AE right away -- just resign yourself to that fact.

Fortunately, there's a guy at Adobe who's gone to great pains to assemble all sorts of freebie AE training resources for you. You should take advantage of it:

http://blogs.adobe.com/toddkopriva/2010/01/getting-started-with-after-eff.h...

.....and GOOD LUCK!



Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Vincent Strader
Re: Rendering green screen too much with keylight?
on Feb 25, 2010 at 4:44:39 pm

Mr. LaRonde,
You Almost have it figured out about where I work. I can tell you've worked around the block once or twice. The bosses here are really cool though and I don't think I'd like any other. They're just not video types that understand how difficult things can get when they say, "Make it happen make it happen."

About the keying issue...I was assuming from past videos other departments handed me that keying would be a struggle inside FCP. But this time I did it myself.

I've lucked out, I lit this backdrop so well, along with the subject sitting in front of the green screen really good, I don't need Keylight. The chroma keys inside FCP are working perfectly for me. I don't have Adbobe Premiere in this version of CS4, it had everything BUT Premiere. I was crossing my fingers we'd get that package.
I'll definitely save the link you provided and also keep in mind what you said about capturing in a different codec inside FCP7.

Thanks!



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Paul Conigliaro
Re: Rendering green screen too much with keylight?
on Feb 22, 2010 at 9:59:39 pm

I'd echo what Michael & Dave have already said.

To add to it, If you'll be moving edits & shots around a lot and that's why you want a qt with alpha in FCP, you might be better off just doing a quick & dirty key in FCP, make your edits, then pull your background tracks & foreground clips into AE and pull the key & composite there. That way you can quickly get into editing and not worry about a lot of round-tripping.

Rarely, if ever, do I just pull a key in AE for an alpha. I almost always do the full composite there.

Adobe CS3, Apple FCS2
[Disclaimer: Sometimes I am an idiot and misinterpret people's posts. I'm sorry.]


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Vincent Strader
Re: Rendering green screen too much with keylight?
on Feb 27, 2010 at 12:18:00 am

Is this the type of error/problems that happen with AE when working with HDV footage?

I imported some footage (different effect now) to add a particle effect.

The footage in the preview window was all there. I mean all the footage displayed.

But in the project time line only a portion of it would display.

I figured out how to get the portion I wanted to work with though by sliding the video time line for a while. I wish there was a simple in and out point you could do on the upper preview window to select though.

As I was previwing ram so I could hear the audio I need to hear I kept getting these errors:

After Effects Can't continue" An Input Contract Violation has occured

After Effects: AEGP Plugin Premiere Pro Import: Unknown Error.
(5027 - 12)






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Michael Szalapski
Re: Rendering green screen too much with keylight?
on Feb 27, 2010 at 12:57:28 am

[Vincent Strader] "Is this the type of error/problems that happen with AE when working with HDV footage?"

All kinds of weirdness can occur. So; yes.

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.


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Vincent Strader
Re: Rendering green screen too much with keylight?
on Mar 4, 2010 at 5:43:24 pm

I don't know if this is what you all are talking about when referring to the errors with HDV footage inside of AE.
But the same thing happened when I expored a QT movie, however I think the format I changed it to when I exported was still HDV :) Woops.

When I took it into AE the other day ( I work for the city fire department which is why I post randomly and at later times). Nothing worked right.

I followed directions on a video tutorial step by step.

But the issue might not have even been with the HDV footage, it might have been with the color background I used.

Instead trying to type my confusing experience I'll post a screen grab of the raw footage, the footage keyed inside of FCP7, and the footage I (only started) keyed inside of Keylight.

If you wonder why I chose this color of a backdrop... look closely at the subject I was trying to key :) Every freakin' color of the rainbow.

I could only think of this magneta-neon purple color as opposite of every color on the puppet.

Dusty the Fire Safety Dragon before keyed
http://i55.photobucket.com/albums/g143/avguy75/DustyNotKeyedFCP7.png

Dusty the Fire Safety Dragon keyed inside FCP7
http://i55.photobucket.com/albums/g143/avguy75/DustyKeyedFCP7.png

Dusty attempted inside of KeyLight, it only got worse even when I followed step by step.
http://i55.photobucket.com/albums/g143/avguy75/DustyKeylightKey.png

It's as if the matte could not make the screen or the subject a trule and separate black or white. It all just meshed together.

I started wondering if it was because of the blue color Dusty was being too close to the purple screen.

We got it figured out to where it looked OK inside of FCP and just went with it.

There might not be an answer for this, I'm just sharing the experience.



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