ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

Using Dual Lasers for Chromakey move matchup?

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Ryan OrrUsing Dual Lasers for Chromakey move matchup?
by on Sep 11, 2011 at 9:56:02 pm

http://canon5d.wonderhowto.com/blog/commercials-utilize-canons-powerful-vid...

What is the purpose of the lasers, and how do they help track and match the moves with the HDR timelapse? I'm incredibly interested in understanding this, because I just can't wrap my head around it and it's very intriguing.

Are there just the two lasers on top of the camera? Or is there more to it then we can see in the video?

Thanks!


Return to posts index

Roland R. KahlenbergRe: Using Dual Lasers for Chromakey move matchup?
by on Sep 12, 2011 at 4:59:50 am

Hmmm, hard to tell but my guess is that he's using the lasers to help him match the chromascreen shots to footage that already been shot. The lasers allow him to match to two points within something similar to a corner pin effect within the timelapse footage.

He's got his camera rigged for z-rotation and XYZ position moves but his main objective seems to be to try to match the z-rotation and z position. I believe that they broadcast in HD and the Canon maxes out at HD, thus not giving him much room for resizing.

Honestly, I think it's a waste of space. If he wanted more space to play with then shooting at a 90 degree angle would have given him more room in post to muck about with.

HTH
RoRK

Intensive AE & Mocha Training in Asia.


Return to posts index

Ryan OrrRe: Using Dual Lasers for Chromakey move matchup?
by on Sep 12, 2011 at 6:15:40 pm

Okay, I get that he is using the laser dots to track something in AE, but what is that "something"? Wouldn't the two points of the lasers simply be stagnant on the video? I mean, if both the camera and lasers are moving in tandem, what's the point of tracking it?

A dual laser would mean that he is not simply stabilizing the shot, but rather tracking both scale and rotation. The ONLY means that I can reason why he is using the lasers is that he would pan the camera while shooting. As he pans to either side, the laser's shape and size would change. Somehow, that difference would be analyzed by AE, and then would be applied, somehow, to the time-lapse backgrounds so that the chroma keyed talent and background would match up.

Were the lasers used during the time-lapse? I don't think so. You could easily track a brick of a building or a street lamp.

In the one Behind the Scene video, the way he travels the camera on his camera on the slider, it would seem that the lasers would have crossed over the talent. I don't believe this shot was used on the final spot (you can kinda guess that from the two different ways the weatherman walks), however would it be paramount to keep the lasers on the green screen, and never cross over the subject?

I don't know. I have access to a green screen, and I'll grab my own DSLR and get my own timelapses. Hopefully by going through the motions, I'll be able to pick this apart and answer the question of why it is essential to have a DUAL laser system for this moving chroma key shot.

But please, do comment and help with any of the solutions!


Return to posts index


Roland R. KahlenbergRe: Using Dual Lasers for Chromakey move matchup?
by on Sep 12, 2011 at 11:23:42 pm

I can only see it being used for alignment during the shoot and not tracking in post. If it was for post then conventional markers would do the trick.

It's much ado about nothing much as far as I'm concerned. Shooting at a 90 degree angle and using Orient to Camera should provide sufficient leeway in post. Having said that, it doesn't hurt to have a bit more precision in matching the chroma shot with the backing plate during production.

HTH
RoRK

Intensive AE & Mocha Training in Asia.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]