PDA

View Full Version : green screen keying?



Caveman
04-08-2004, 01:31 PM
Hello DVX-ers. I was surprised to not see any posts on keying with the DVX. I've had fairly good luck with both 60i and 24p but have not attempted 24pA just yet. I was looking for some advice more on the DVX side of things i.e. scene settings/ shooting modes. I've been a digital compositor for about 5 years now having worked extensively in AE, Combustion, and Shake.
I just picked up a DVX-100 to go out on my own in the commercial and music video production biz. If anyone has any tips I'd would be most appreciative. Maybe I could repay in compositing tips.

Glad to have joined this fantastic forum,
:D the "CAVEMAN"

kai
04-08-2004, 02:23 PM
Hey caveman, glad to have you! ;D

Caveman
04-08-2004, 02:29 PM
:) Thanks Kai.

Man....you can spend days going through these threads.

I'm never going to get any work done !!!

skettalee
04-08-2004, 02:30 PM
Dude you should just give us some tips anyway. If I would have more to say I would. All I gotta say on the green screen keying is LIGHTS LIGHTS LIGHTS. Make sure you have a solid coloring of your green so light your work well. Also im sure you know but keying is very easy in AE. I even know of a cool little tutorial that can help you more :

http://www.creativecow.net/articles/chromakeying.html


(Sorry I cant help more on the DVX side of things, i dont have one and need one. When you get a new one, give me your old one!)

PS : Good luck on going out on your own, I know it can be hard though I havent really gotten deep into that yet, i just know it! You can do what you put your mind to though!

Guest
04-08-2004, 04:20 PM
;D Thanks Skettalee?? I've actually been pulling keys for about 5 years but I've never actually shot the footage and most of the keys I've pulled have been on high-end ($30,000) cameras. Fortunately I've picked up some great old lights from my previous employer and aquired some pro screens. Pulling keys on minidv is actually way harder than 35mm or digibeta or just about anything else. I'm just going to experiment with the modes and pulldowns and see what works out the best out of all of them with the least amount of pixelation. I was thinking it had more to do with the interlacing but now I'm not so sure.

Here's my professional advice so far on keying digital....

If using AE6 pro.. Keylight ... boost the strength to usually around 110 to 112. Then .6 to .8 on the screen pre-blur.
Then to clean up the pre-blur you just added add a matte choker or a simple choker. Adjust to your likings. That usually works pretty well on well lit screens. Not so well lit screens....thats another story. Some other tips are traveling garbage mattes. And of course the biggest of them all is MULTIPLE matte keys.
i.e. one for the head and hair another one for the arms (if they're moving) and then maybe just one more for the rest of the body, if you're lucky.

Anyways thanks for positive comments on starting out. Fortunately I have much support from my wife (the bread winner).
She's putting in quite a bit of O.T. til things pick-up.

Thanks again.... :D caveman :D

kai
04-09-2004, 08:24 AM
Fortunately I have much support from my wife (the bread winner).
She's putting in quite a bit of O.T. til things pick-up.


What a blessing man... Best of luck to you, and we're glad to have your expertise around here :)

skettalee
04-09-2004, 12:51 PM
thats great man, what kinda work are you doing for green screening or everything in general?

hemophilia
04-09-2004, 03:52 PM
Howdy Caveman,

Here's a little thread showing a key I pulled off the DVX:

http://www.dvxuser.com/cgi-bin/DVX/YaBB.cgi?board=Clips;action=display;num=1080882004

and another with some footage from different people:

http://www.dvxuser.com/cgi-bin/DVX/YaBB.cgi?board=nws;action=display;num=1080631478

****************************

As far as techniques go, the CrCb blur is just the best damn thing you can do with DV (different from say 35mm scans or something), because of the 4.1.1 color sampling. You said you use Shake; that makes it really easy.

One of the other links someone posted gave some good advice about first doing a test shot of the type of screen you'll be using with your DVX, and figuring out what exposure gives you the highest chroma reading off a vectorscope. Then make a point of always exposing your screen precisely in that range.

I look forward to seeing some examples of your handiwork posted up here. Cheers.

Caveman
04-09-2004, 05:31 PM
Well...in order of appearance.....I'm doing some spec commercials right now as key tests. One is for an Animal Planet network package with random keyed out animals in "GAP World". Some of them are pretty tricky i.e. fast running lizards. I've been having a hard time keying out a GREEN tree frog. Ha!! I'm also in the process of doing alot of compositing shots for a music video I'm working on. I'll post it soon. Should I post that stuff in here or in the screenshots forum?

Hey Hemophilia!! Thanks for the input. Unfortunately all the experience I've had with SHAKE is kind of in the tubes now that I'm doing my own thing and it just wasn't in my budget to get it. But I have to say AE6 Pro and Combustion have really stepped up to the plate. Each has its pros and cons but between the 2 theres not much they can't do.

Nice Key by the way. I was going to ask if it was shot under the sun until I saw the green patch on the garage door! I didn't see any DV "jaggies" at all. KUDOS!

And today I got a little experimenting in.
Heres my results ....and the hardcore 24people aren't going to like it.
And the winner for Best key shooting mode goes to..............
30p !!!!
I think the problem with 24p is that with the pulldown it makes several interlaced frames and its the interlacing that kills you.

I have yet to remove the pulldown in AE to work on a 23.98 timeline though. I was just doing it in 29.97. I'll post any new findings as they come.

Thanks again everybody,
CAVEMAN 8) 8)

hemophilia
04-09-2004, 06:13 PM
No no no... 24P is a'ight. Yes interlacing kills you, but DVX100 records true progressive 24P, and in the advanced mode (with software that can handle it) there is NO interlacing artifacting whatsoever. There are a gajillion threads around here about what software handles the 24P advanced, and how to deal, etc....

So really there shouldn't be any difference between the two except the subtle shutter speed difference (when it comes to pulling a chroma key).

Do you know of a way to do that CrCb color-channel blur thing in Combustion easy? I've never messed with combustion, but I too am interested in it, cause from my cursory look it seems like quite an amazing piece for the price... and much more of the pro-style interface than After Effects.

Caveman
04-09-2004, 07:34 PM
A gagillion threads is right. *I've been racking my brain over this 24p thing since I got the panny a couple of weeks ago. I understand the idea of it. My big concern is mixing up footage in AE and then back to FC4. By mixing up I mean compositing different framerates in AE. *Just the general workflow between FC and AE. *I'll figure it out sooner or later but reading these threads about it just confuses me even more. I'm more of a figure it out for yourself kind of person, it's the only way it really sinks in with me.
Anyways color channel blur in combustion is really easy to do.
And you're right about the interface. If you've ever worked on Shake, especially an older version, Combustion is a walk in the park. *Things like Branches and Nodes and the schematic view make it a much more professional app. *I bounce back and forth between AE and Combustion. *The only proper schooling I've had was mostly in graphic design (photoshop/illustrator) so working in *AE is so much faster for me, and alot of my composites utilize graphic items imported from PS and AI so its just kind of a nice workflow. Combustion definitely for rotoscoping, wire/rig removal type stuff, and color correction. OH the color correction!!! *Let me know if you pick up combustion. I'll help you out with the CrCb. * * * :) CAVEMAN

Caveman
04-09-2004, 08:47 PM
Oh yeah I should probably mention the lack of stability of combustion on a MAC. I couldn't tell you about on PC for sure but I haven't seen as many complaints from them as I have from MAC users. I myself have had only a few minor issues and one major one that actually seemed to be fixed by clearing my user prefs and beefing up from 1GB to 2GB ram.
Then on a more positive note the matte shrink, erode and blur controls are just like on the newest version of Shake. Super FAST.
I could probably go on for a while.
But I got an hours worth of live band footage to weed through and log and capture. See ya tommorrow.
CAVEMAN

SirAllen
04-29-2004, 12:49 PM
Doesn't look like anyone mentioned it, but the main camera setting you need to be concerned about is DETAIL. Keep it down low, like -4 or -5 or otherwise you have a sharpening halo around whatever you try to key that'll be hard to deal with. Other than that, it's lights lights lights and make sure you have a decent keyer (keylight is nice, but I personally like DVMattePro from DVGarage the best in AE). In terms of 60i, 30P, 24P, or 24Pa - it doesn't matter which you use. I like to keep away from 60i to have more resolution per frame to work with, but some pros swear by 60i for composite work!

Guest
05-22-2004, 09:57 AM
I may be in way over my head by commenting here but let me try.

Are you familiar with Serious Magic's UltraKey or even Visual Communicator?

With either program you can plug in your DV Camera and run the program. Point you camera at the green screen and both programs remove the green entirely. Visual Communicator is entirely different program than Ultra. VC is made to do short little classy commercials, introd to training videos etc as the video screen itself becomes a teleprompter. The keying is not as powerful nor does it have as many controls.

Ultra, on the other hand, keys out poor lighting, wrinkles on the screen perfectly. The algorithms used are nothing short of phenomenal. With Ultra if the program shows you that the green screen is set up right (and with this program its easy to do) you then just start filming. Come back to Ultra to key it out by running what you have taped through the program.

check this out hxxp://www.seriousmagic.com/ukoverview.cfm

kai
05-27-2004, 08:25 PM
note: this is a repost of seantree's last post on this thread... it was accidentally deleted. Sorry bro! :)

Post:
Caveman, I see you mentioned AE6's keylight plugin. I would recommend using it. I've pulled some very decent keys using a crappy 1 CCD cam with it. It seems to work much better than Combustion's keyer with the cam I am using now. can't wait to test it on the DVX ( no i don't own one yet *)

Curugon
10-07-2004, 06:10 PM
Just wanted to toss in my two cents...

I've been shooting/keying miniDV footage for about four years now (and haven't gone insane), so hereís a few pointers for the low-budget crowd.

For those who cannot afford stages/arclights, here's a tip: grab either a chromakey foldout (like those windshield screens) or a roll of chromakey paper (either of those sold at good film supply stores). Find a nice location with an open area that's under shadow for most of the day, and set the screen up. The natural ambience will evenly light the screen (provided there's no weird bounce or reflections anywhere). Best case scenario, there are open areas of sun nearby, so you can set up bounce (white/silver/gold etc) to light the subject. Yes, this light will change as the day goes on. It ainít the Ritz, but you can get some surprisingly good results from this MacGuyver solution.

On the AE side, I recommend Ultimatte and Primatte - each has their own strengths depending on your footage. I haven't tried the DVgarage plugin yet. If you canít afford a third-party plugin, go with AEís built in ďcolor rangeĒ keyer, and matte choker. Donít forget to use multiple keys for different areas (body, hair, skin, etc).

Brutal truth: almost no keying can be done entirely without some creative rotoscoping. Rotos can save your shot, and the better you get, the fasting itíll be. Who knows, it may even be fun.

BigMucho
10-08-2004, 10:04 AM
I used Ultimatte Advantage for about a year, pulling decent 4:1:1 keys, but render times really suffered.

I tried Keylight for a while and liked it.

But I now use DvMatte from DvGarage exclusively. It's fast and very flexible.... and I'm pulling the best keys yet.

You should also be doing some "light-wrapping" this can really help your results, try Red Giant Software's Composite-Wizard.

Here is an example:
http://www.bigmucho.com/dvxuser/FrenchChef.jpg

Later, Ethan

HansK
10-08-2004, 12:17 PM
Here is an example:
http://www.bigmucho.com/dvxuser/FrenchChef.jpg

Hey, that's nice. Keying can be so cool.