Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Need some help with post production

Mark Collins

Mark Collins

Well-known member
Joined
Oct 16, 2009
Messages
431
Reaction score
0
Points
0
Location
Toronto, On
Ok, so, here's the background info, and then I'll tell you the issue:

So, I'm a film student at Sheridan College in Oakville, ON. For my second year live action class, we had to shoot a scene from Casablanca, the scene where Victor and Ilsa leave Casablanca, basically the ending scene. We had to do moving shots and had to shoot against a blue screen.

Well, I find myself doing visual effects for one of the groups in my class. however, this group essentially took the phrase "we'll do it in post" way too far. They didn't have even lighting across the blue screen, and for some reason they shot in front of a black curtain as well as the blue screen because they wanted to have the curtain "represent night".

Basically, between their terrible lighting and absolute zero knowledge of how to shoot on a blue screen, I am now stuck with damn near unworkable footage. Unfortunately, the deadline is next monday at noon. So, here's what I need to know. Are than any tips and tricks I can use in after effects to try and make this footage workable in a limited time frame whilst working on a laptop?

A HUGE thank you to anyone that can help me out here.
 
What was it shot on? This makes a huge difference as to how well it keys.

First of all you may want to do an animated garbage matte to minimize the area you need to key.

Second you should probably use multiple keys. If you try to use a single, it may have to be so strong it eats into your subjects.

Third, may as well try pulling a luma key off the black curtain. If the bluescreen is bad enough, you may actually end up with a better result, though I'd doubt it.

Fourth, make sure you are working with pure footage. Don't use third generation or resolution reduced transcodes of your footage.

Without knowing anything about what you're doing, that's about all I can think of.

Best of luck.
 
jimhare said:
What was it shot on? This makes a huge difference as to how well it keys.

First of all you may want to do an animated garbage matte to minimize the area you need to key.

Second you should probably use multiple keys. If you try to use a single, it may have to be so strong it eats into your subjects.

Third, may as well try pulling a luma key off the black curtain. If the bluescreen is bad enough, you may actually end up with a better result, though I'd doubt it.

Fourth, make sure you are working with pure footage. Don't use third generation or resolution reduced transcodes of your footage.

Without knowing anything about what you're doing, that's about all I can think of.

Best of luck.
Click to expand...

He's totally got it. Can't really do much more. The Luma is likely the best on the black and should almost completely save you there.

Also do some color grading to help improve that first then do the luma, then apply it back to the original footage. Basically crush black to black.

Anywho good luck!
 
Rotoscope

Rotoscope

You can output 4K TIF frames and enlarge them to 8K in a graphics program, the put those in a paint program and paint in a good green as rotascope all over the background, doing that at 8K gives you more room for small single pixel errors around the edges.

After you rotoscope in the paint program, do a light blur on the 8K images and reduce by good resample (not skip pixel resize) them to 4K for processing as chroma key.

While you rotascope you also need to retuch any green reflections that would make "holes" in the A/B mattes (negative and positive alpha layer).
 
In this instance I wouldn't listen to Dan. You'll just get too much chatter and boiling--especially if you don't have professional experience in such work.

What software do you have? This is the sort of case Nuke's IBK was meant for. Create a clean plate, track it in and use it as the IBK color input. Beyond that Jim pretty much covered everything of any importance. Single channel Luma Keys are life savers as well.

BTW. I assume you own copyright and don't have NDA. Post a still and we can probably be much more helpful.
 
Linwood Dunn

Linwood Dunn

Gavin Greenwalt said:
In this instance I wouldn't listen to Dan. You'll just get too much chatter and boiling--especially if you don't have professional experience in such work.
Click to expand...

Linwood Dunn "always" had to rotoscope his blue screen mattes, I know because I was in the room when that was said.

http://en.wikipedia.org/wiki/Linwood_G._Dunn

If the "autopilot" does not get you there, you need to know how to fly the plane, and better you should learn now on projects that are not going to get you fired from your once in a life time position later.
 
Dan Hudgins said:
Linwood Dunn "always" had to rotoscope his blue screen mattes, I know because I was in the room when that was said.

http://en.wikipedia.org/wiki/Linwood_G._Dunn

If the "autopilot" does not get you there, you need to know how to fly the plane, and better you should learn now on projects that are not going to get you fired from your once in a life time position later.
Click to expand...

That's REALLY cool! btw.. I wasn't doubting your tech about painting.. just the kid's available time to do it.

best,
~s
 
Dan Hudgins said:
Linwood Dunn "always" had to rotoscope his blue screen mattes, I know because I was in the room when that was said.

http://en.wikipedia.org/wiki/Linwood_G._Dunn

If the "autopilot" does not get you there, you need to know how to fly the plane, and better you should learn now on projects that are not going to get you fired from your once in a life time position later.
Click to expand...

And better to learn modern rotoscoping technqiues now than when your comp supervisor kicks back all your work for having too much chatter or peaks in after 3 weeks to see why you aren't done yet.
 
Thanks guys for all the help. Unfortunately I do not have the time to rotoscope at all. I have to hand it off to the post sound guys today, and with the amount of footage to go through, it's simply not possible to roto it all.

I'll definitely try some of those techniques though.
 
I tried roto once. After three hours I think I completed about 4 seconds of footage in a 3 minute sequence! I gave up and did my best with the tools and got a pretty decent result. I'll never be happy with it but no one else seemed to notice.

I guess it's all about weighing up how much work it will be, how much time/budget you can allow, and how important the shot is.

Probably not good to blow you entire VFX budget on the end credits! :biggrin:
 
You must log in or register to reply here.
Back
Top