Lesser of Two Evils

WE have been working on a project called CXL for a few weeks now.  In those few weeks we have shot some greenscreen footage for the film on the Panasonic hpx500.  The director Sean Gillane explains to me that this is more of a broadcast camera and not the best for Greenscreen extractions.  We decided to give it a try since our other option was a Canon 5D Mark ll.  The issue that this camera has when trying to pull a good key are the Red and Blue channels.  These channels have a tendency to be noisier than the Green channel.  Also you end with with this nice white line around the image that makes it really hard to key.  Check out my examples of these channels bellow.

           Red Channel             

      Blue Channel

The Canon 5D Mark Two  is a great camera and I love shooting with it.  To steal a phrase from Stu Maschwitz (his prolost blog is a must read) the 5D is an amazing Rebel camera, and it has done a lot for the VERY independent and not so independent film making community.  That being said it still has a lot of issue when shooting on Greenscreen.  the main issue is that its output is H264.  You end up with compressed footage that you have to try and get a key from.  Check out this alpha channel with a lose key pulled, you can see the compression ‘s square artifacts.  This will make pulling a key tougher, especially around the fine hair area.

 Nice chunk of compression

Compression causing the hair to crunch

In this photo you can see on the back of her hair that its starting to crunch.  This is due to the compression.  There are tricks around this of course but I would obviously prefer to use a better camera.  

Quick comp with crunched hair

One way around the compression issue would be to use a Aja Ki Pro mini.  We thought this was going to be our savior for our compression issue.  It bypasses the camera’s compression and you get  a nice ProRes 422(HQ) file.  The only problem was that it didn’t seem to work with the 5D.  We could only get a 29.97 FPS and no 1080p.   Major let down when we found out that we could not use the Aja Ki Pro Mini.  

We have one greenscreen shoot left and I still need to figure out if we should use the Panasonic hpx500 or the Canon 5D Mark ll.  I keep going back and forth with this one.  

Ill see some keying results with the hpx500 and say “Lets use this one on the next shoot” then I see some keying results with the %D and say the same thing. 

We are shooting in a few weeks and I am now leaning towards the 5D.  One major reason is because the plate for the GS shoot was shot on the 5D and thats really the only reason. 

If anyone has any suggestions feel free to post some comments!

Launch NukeX from MacOS Terminal

I decided to write this simple and quick tutorial on how to Launch NukeX from the terminal since it took me a while to figure it out.  I am not very good with command-lines which is why it took my some time to figure this out. hopefully this will save you a lot of time.

Open terminal and type: sudo nano /etc/profile

(Might ask for a password)

After you type the above, a new screen will pop up that looks like this

Under # System-wide... is where I put my alias, Here is what I typed:

alias nukex="/Applications/Nuke6.0v7-32/Nuke6.0v7.app/Nuke6.0v7 --nukex"

And your terminal should look like this.

On this screen you can add as many alias as you like just change the version(Nuke6.0v6 or Nuke6.1v1).  I had one with no --nukex just to launch regular Nuke and I also have a few others for different versions of Nuke that I have on my computer.  Just remember to change the name of the alias for each version you add.  

This is a per machine bases so if you are on a network this will NOT follow your profile.  Each time you move and log on to a new machine you will have to redo this. 

Hit Control and X to quit then hit Y to save and enter.  Close the Terminal and reopen it and type it nukex (or what ever you put as the alias) and NukeX should launch.

Special thanks to the Foundry, Brian, and Tahl Niran

Basic Key - Alpha Channel

Here is a quick key I pulled in Nuke.  I used the IBK Gizmo for the edge matte and a Primatte as the Core matte.  There are still some holes that need to be filled but I'll do that later.  

I downloaded a Gizmo called the Grad that allows you to take four samples of the greenscreen and gives you back an average.  It's a lot like the IBK color but seems to work a bit better for motion blur and especially after adding a grade node to it. I got the grad node via FXPHD recommendation then downloaded it from here .

 Picture of the IBK with Grad node with Grade node and the Primatte keyer.

Here is what the Grad Node options look like

Here is the Alpha Channel that I got from the IBK Gizmo and Primatte Nodes.  (Still has holes)

Alpha Channel from Ken Fisk on Vimeo.

Basic Key - Background

Here is the Background I decided to use.  I shot this outside my work with a Canon 5D Mark 2 with the kit lens which isn't my favorite lens by any means to slow for me.

 

Basic Key

I plan on keying this very quick shot and posting a few steps along the way.  Not at all a Tutorial just a few steps here and there. The rack focus is going to be the only tricky part and I don't think that should be to tough on such a short shot anyways.  

Bike_Pedal from Ken Fisk on Vimeo.