Need big picture walkthrough for greenscreen workflow,calibration, color balancing...

G

greg sage

Member
GH2 with 14-140 and lighting on it's way for indoor studio greenscreen music video shoots.

Been reading up on a number of things, and just trying to put together a big picture workflow for what needs to happen. Here's my understanding of workflow so far. Input and/or corrections appreciated.

1 Setup full body 16 foot wide greenscreen (plus floor)

2 Set up lighting (5 point setup, but one extra point to hit middle of screen in back)

3 Dial in lighting amount with camera (still reading up on this one. Basically want lowest noise, so zero digital gain, fastest shutter (2.8 for my lens at distance somewhere in 10-20 foot range from subject (still working on).. Then use grey card to help determine exact right amount of light, dial back lights as necessary.

4 Shoot white card. Set white balance

5 Shoot Macbeth chart

6 Shoot video (still not sure best hack to use, want to preserve max color information for key

7 Import into mac with FCP (should I get a card reader, or just go in from camera?) Also, still reading up about various codecs for different hacks... back to which format questions)

8 Key out greenscreen (A friend has video editing suite with FCP. Should I use this or something else?)

9 AFTER KEY (if I have that right), take foreground subject footage, and apply color correction (Not sure if FCP has tools for balancing with macbeth chart or if it's separate software)

10 Edit footage, do transitions, allign to music, etc

11 Any other stuff like after effects or stylistic tools to apply

12 Titling (Done in FCP, or any suggestions?) I have some basic animations I could include from Anime Studio... not sure if they should be imported and composited in FCP.

13 Render to final output for mainly youtube consumption (I'm thinking 720p 30fps with highest possible quality audio.)




So... I know there's a few holes in it, but I have to start somewhere. Appreciate any info about overall workflow and/ or any specifics for various points mentioned.

Thx.
 
Step 10 should come after step 7. Edit your video first with the greenscreen shots left un-keyed. Get your pic-lock done frist. Keying first and then editing can end up wasting a ton of time if you end up cutting or switching those shots around. Once your final edit is locked in, then key your shots.

While I've seen FCP produce some really nice looking keys, I wouldn't recommend it. You'll probably get better results in AE.
 
ErikTande said:
Step 10 should come after step 7. Edit your video first with the greenscreen shots left un-keyed. Get your pic-lock done frist. Keying first and then editing can end up wasting a ton of time if you end up cutting or switching those shots around. Once your final edit is locked in, then key your shots.

While I've seen FCP produce some really nice looking keys, I wouldn't recommend it. You'll probably get better results in AE.
Click to expand...

Sorry, a bit confused. Did you mean that step 7 should come after step 10?

Ok, been reading up that key should come before any color correction, so you're suggesting editing, then keying, then, color correction/ stylistic tweaks?

FCP is just one tool I know I have available (a friend has an editing suite based around it). Have to check, but other tools may require purchase (which may or may not be doable depending on details) Will look into AE. thx.


Any other input on the rest of the lineup?

For this first video, it won't really matter about where the key is since it's so locked down as to where each piece of footage goes, but they may not all be like that. I was under the impression that the keying wasn't terribly difficult, but was more along the lines of grabbing a piece somewhere, tweaking it to get the settings right, and pressing "go." The rest will just be automatically keyed according to the settings you chose from the first bit. From there, you've got a "floating" foreground only footage that can be dropped in. Was that assumption incorrect?
 
Greg, I see you decided on the GH2 in the end. Good choice, especially for low budget that you're planing on doing.
 
Hope you're right, of course. Obviously, the money savings was significant... so I've been able to put some more into the lighting (just bought 6 pretty serious fixtures yesterday)... and then have some budget left over for any software, peripherals, etc. Would have preferred 4:2:2 and the like, but in the final analysis, I've been quite impressed with the overall quality of footage I've seen from gh2... and I can get some better quality keying software if necessary.

As an extra plus, it's a camera that can be carried int the traditional tourist sense, so my GF also feels like she's getting an expensive new toy. Never underestimate the power of a happy household.

As to the workflow part... I don't know of I'm searching wrong somehow... but I'm just not finding info about the software/post side of using a macbeth chart. I see some tutorials using photoshop, but not vegas, fcp, etc. I was under the impression you just shoot the chart, then at the end of your post process, you reference the chart, and there are automatic tools to make all the necessary adjustments quickly. Mind you, I'll likely juice a few things from there, but I thought I should at least start from the best color corrected images possible.

Are these automatic tools built in? Is there a best type of chart or editing program to be using for this? Only auto tools I've come across thus far are in still image programs, and not nle's.
 
In my quest for greenscreen success, these were recommended to me:
1. Remember the green doesn't need to be lit to the hilt
2. Use historgram to check your lighting of the backdrop making sure it is as even as possible
3. Rim lighting is a huge help
 
ok, thx. Watching some greenscreen tutorials when time permits.

Some big picture stuff still looming and keeping me from moving forward, thoug.

For instance, Youtube recommendations for upload are:
Video
Format : AVC
Format/Info : Advanced Video Codec
Bit rate mode : Variable
Bit rate : 5 500 Kbps +++
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Scan type : Progressive

Audio
Format : AAC
Format/Info : Advanced Audio Codec
Bit rate mode : Constant
Bit rate : 256 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz

So... I know what my target OUTPUT is, so what does that tell me about the right patch to use, codec, etc? I have FCP available at a friend's place, and I believe he has AE as well. Need to narrow down all the variables and make a move here.

1 Which patch? Quantum 9b at 1080p 30? Too high bitrate? Something with steadier bitrate? Do I need GOP 1 for crispest key? 1080 definitely better for keying due to more total color info? Stable enough for no worries?

2 Memory cards vs blackmagic card into macpro... sounds like a nightmare the hdmi issues. Worth it and doable in my situation?

3 Frame rate: Since Youtube output should be 29.97... does that mean I shoot in 30, or is there a way to use these patches and actually shoot in 29.97?

4 codec... any special considerations for best gh2 hack in terms of workflow and codec going into NLE?

5 Best keying software? ("Best" also referring to any workflow issues with NLE)

6 Any other bugaboos I should know about? FCP, AE are running on 2008 ocotocore macpro.

7 Should I buy a card reader if I'm using the cards, or can I just read it out from the camera to computer?

8 Color chart: Still can't really dig up much info about use of color charts on the back end. Is there an automatic thing that can be done in FCP to balance out a macbeth chart? See lots of info for photoshop, but not for NLE's.

9 White/ gray balance. Set white balance (temp) with white card and then exposure with gray card? I see all sorts of seemingly wompus things people are doing in this regard and just want to get it right.
 
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