DVCPRO HD GREEN SCREENING
It ain't easy...let me tell you what...
I currently have 18 shots in the show that I need to composite. They were shot against a green screen, and are to be added to several castle shots that were shot in Mexico...Bishops Castle to be exact. For the rough cut I just used the Chroma Keyer in FCP, but after futzing with it for a bit I knew that I wouldn't rely on it for the main comp.
Here is the raw image:
As you can see, there is a bit of motion blur. This is due to the fact that the footage was shot 24P with the Varicam...23.98 footage. The motion blur looks very filmic, so it is what we were looking for. But the FCP keyer didn't key thru that/ Here is a still from that attempt:
Close...but not quite. So I was looking thru the Creative Cow Tutorials seeing if I could find something when the perfect solution seemed to present itself: KEYLIGHT in After Effects. So I imported the clips and added keylight, eyedroppered the green and BOOM..this happens:
WOW! Perfect. That is exactly what I wanted. Sweet...and that is the basic setting. I haven't even started to choke the edges or anything. So, I did this and was happy. I moved to the next clip...and...something odd happened. Or rather, I noticed it for the first time. When I brought the clip into After Effects it seemed to brighten...the luminance increased. So I called a buddy of mine who is a Motion Graphics artist and asked him what was up. He said that he found that Keylight really wasn't good for DVCPRO HD footage. It added noise to the blacks...something that I didn't notice because the first clip I did this with was pretty light. But the second clip...well...look:
There are a lot of dark areas. So now I use Keylight and I got this:
Look close. Look in their hats and on the blue jacket on the man on the right...the one facing away from camera...light blue jacket. There is a lot of noise. Take a look again at the first pictures. Notice that the Keylight image is lighter as well. I turn off Keylight and it goes away. Nuts. Now what? My buddy says that for DVCPRO HD he uses a plugin called DVMatte Pro by DV Garage for After Effects. But it is available for FCP as well, so I download the demo and play with it. It keyed VERY well...I will have to say. BUT...but but but. Dang it there had to be a "but." It doesn't see thru the motion blur like Keylight does. It chops it off.
Look at that compared to the original shot:
Look specifically at the gun of the soldier on the left. Comparing them you can see that DV Matte Pro doesn't see thru the blur, but chops it off. I went thru their tutorial and futzed with settings and still couldn't get it to go away. PLUS...plus...I have the added feature that there are TWO SHADES of green screen. 
The nice normal green you see in the upper part of the picture, and this dark green screen in the lower part of the picture. Keylight, the wonderful tool that it is, can key both colors. DV Matte Pro does not. Well, I couldn't get it to. If anyone knows how to do this, let me know.
Another friend of mine, a commercial editor who inspired me to make my popsicle stick RAID, happens to know Shake very well, and says that Keylight with it works very well. And since Shake is really cheap right now ($499) I ordered it. Heck, if it is good enough for KING KONG and LORD OF THE RINGS and STAR WARS...it should work for me.
Testing it tomorrow.
6 comments:
Hi Shane,
Could you send me an export of a few frames of the motion blur material? tom@SouthCoastTV.com I would like to try a couple of keying tools on it, zMatte from Digital Film Tools and vKey from Oak Street Software.
Thanks.
All the best,
Tom
Another vote for Shake using Primatte/Keylight with DVCPRO HD. We had the best luck pulling a hold-out matte with Keylight and the final key with Primatte. Ckeck out the Cook Book that comes with Shake for some handy keying tips and a few extra macros as well. Theres also plenty of keying macros on fxshare.com for shake.
JH
Shake will work, as i use it practically everyday at my job, but understand, all those other options will work also. Properly keying footage is not a "drop" the filter on the footage, click the green, and get a good key. Keying properly is a major multi step process to do it correctly, from creating the ketmatte, using garbage mattes, adjusting greenspill, and color correcting. Many times these things might also need to be keyframed to change over the course of the shot. From some o your comments, I gather you are not an experienced keyer, so one of the best places I can think of, is head over to DV garage.com, Alex Lindsey's site, and there are several free tutorials on properly pulling a key. Also understand, SHAKE is extremely complicated, and will be the hardest one of all those programs for you to use unless you do some serious traiing. (You need to specify EVERY step to shake, it does nothing automatically.)
Turn off the spill suppression in Keylight, and do the spill suppression as a separate pass. It's hard to tell from your low res screengrabs, but from what you are describing, it sounds like something Keylight would do with the spill suppression on.
I was having the same problem with Keylight tearing up the color channels in AE, and what I ended up doing was adjusting the key until I was satisfied with the results on around the actors (ignoring the problems in the dark areas), and then using the keyed layer as an alpha channel for the original footage. It was a perfect edge, and the footage look the same when I dropped it in.
Having said that, it worked for me because it was a interview without much movement. It may not work for you as well with a lot of motion blur.
--Jason
Well.. I know this Keylight-issue, and the solution is very simple: Just set »Screen Matte/Replace Method« to »Source« (default: »Soft Colour«). This method is slower but eliminates those noisy black blocking artifacts. Hope I could help, -Toni
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