Let me Introduce You to… Adobe After Effects and Green Screens
- sveahartle
- Mar 14, 2019
- 12 min read
This week, and now that our crew finally settled on all the visual effects needed for Plotopius and the Crimes of Craniarc yesterday, I could ultimately start researching not only the required effects, but also the relevant software choices to go along with it in depth.
This also meant that I could finally get an introduction by our technical demonstrator on one of the required pieces of software for this Teacher Central project this morning, which is, in this case: Adobe After Effects.
But let me start at the beginning.
Envisioning Effects
Already with the lock-down of our new script – Plotopius and the Crimes of Craniarc – last week I had several read-throughs of it, looking for hints that would inform me about the types of visual effects that were required, collating them in a list as I went on. While most of the effects were rather easy to discern – such as lightning bolts or meteorites – some were a bit more difficult to find, as they could also very well be created in camera – such as props being handed to the actor from out of frame, etc.
Since the aesthetic of our project is designed to be rather tongue-in-cheek, alluding to video game tropes, both solutions could be read into the script. However, since I was reading the script in my role as an editor, I decided that I would ignore any possible in-camera solution and try to come up with visual effects’ ideas to implement instead. Which led me to this list of visual effects that could be implemented and which I would then need to research if applied:
Chroma Keys – Application of a multi-layered green screen effect
Monitor Inserts – Inserting a white screen on a phone display
Sudden Pop-Ins – Characters and objects popping in and out of existence
Freeze frames
Clothes Change Effect – Much like no 2, except with clothes
A Character’s Stats Table
A H.U.D.
Text Pop-Ins – Blinking Titles
A Game Over Screen – Most likely a rather simple Title Effect
A Loading Screen – Like no 8, but with animation
Lightning bolts
Light rays
The Dragon Ball Effect – As in my blog entry ‘Beat‘Em Up! How to Film A Punch’
Scribbles – Animated lines as in comics to indicate an object’s importance
All this comes in addition to basic editing and matching of dialogue, sounds, and voice-overs with the visual material.
Discussing Effects
With this list in mind, I asked our scriptwriters and director on Monday to sit down with me and discuss it in detail in order to ascertain whether I understood their script (and their intended visual effects) right.
Sadly, our director did not attend the meeting, which means that I will need to bring it up again once more in our production meeting on Thursday to ensure that it matches his vision as well, and if so, that he is aware of the type of shots that are required in order for me to be able to edit the effects as desired.
However, as it turned out, I hit the nail right on its head most of the time, as the scriptwriters did not only envision the exact same effects, but were also pleasantly surprised by some additions that I offered and which they considered doing in camera, such as the sequential popping into being of objects and weapons as e.g. seen in the character development arc. In the end, we settled on this list:
Chroma Keys
Monitor Inserts
Sudden Pop-Ins
Clothes Change Effect
A Character’s Stats Table
A H.U.D.
Text Pop-Ins
A Game Over Screen
A Loading Screen
Meteorites
Lightning bolts
The Dragon Ball Effect
Scribbles
Regarding the freeze-frame effect and the light rays effect, both scriptwriters envisioned these to be filmed in camera, with the freeze-frames being done by the actors, while the light rays would be created by lighting, thus they struck them from my list of effects to edit.
As for No. 13 – the scribbles – we collectively decided that we would only implement them if time permitted, as they are not yet absolutely crucial to the plot itself but might rather be a nice additional detail. Much the same seemed to go for No. 1 – multi-layered green screens. While we still want to try and implement them in order to create a plausible 3D-effect, both scriptwriters feared that it could easily go beyond the scope of what could be reasonably done within this project and its time frame.
As I have not done any multi-layered green screen effects before and thus don’t know how much time they will take in the edit, I opted that I would want to experiment with them first to gauge whether they would be feasible within the time frame and resources given. While I love the thought of being able to do them on the one hand – they would be a splendid learning opportunity that would improve my editing style tremendously – on the other hand, I would personally refrain from using them throughout the entire piece IF they required most of the other effects to be neglected. As it stands now, the creation of a H.U.D. and a Character Stat’s Table could be extremely demanding and time-consuming as well.
However, I will definitely give it a shot before deciding on them further.
The Software Required – Benefits of Adobe After Effects
Luckily with this effects list above, all of the effects can be achieved with the use of Adobe After Effects 6. While Avid Media Composer 8 and even DaVinci Resolve 12 – which are currently at our disposal at university – do come with a certain set of visual effects in editing, Adobe After Effects is the go-to source for more advanced effects: You not only get a lot more choices of editing effects in general, you do also get a better quality and sub-variety of the implemented effects than you would in Avid and DaVinci Resolve.
Introduction Into Adobe After Effects CC
As with most Adobe software packages, the setup and layout of workspaces stays roughly the same and the same also goes for Adobe After Effects CC. Much like with Adobe Premiere Pro CC 2015, the layout of the workspace contains a Project Panel in the top left corner:
an Effects Panel in the bottom left corner:
a Source Monitor of sorts in the middle:
an Effects Control Panel at the upper right corner:
and a Timeline Panel of sorts in the bottom right corner:
With After Effects however, and since you can not only work on video files, but also on images, music files, and other media, the Source/Record Monitor here is instead called Composition Window. Furthermore, with After Effects, the ‘Timeline panel’ and ‘Effects Panel’ as depicted above are – strictly seen – not two separate panels (as they would be in Premiere Pro), but have been merged into one joint panel, which is called Composition Panel.
Furthermore, atop the Project Panel, you can find the Toolbar that contains the most important and most frequently used tools, such as selection tools, the zoom function, textboxes, Rotoscopes, and many more.
Also, as you can see in the image above, a small triangle at the bottom right corner of some of the tool tiles will offer you further options if you click and hold it for about two to three seconds.
And much like with Avid and Premiere Pro, the essential setup and process of importing media does not differ tremendously with After Effects. Instead of media bins (as you would have in Avid) you can create folders and folder structures in the Project Panel to sort your media, effects and compositions (which are After Effects’ equivalent of ‘sequences’ in Avid).
Starting A New Project
In order to start a new project, you open Adobe After Effects CC, click on New Project, then on New Composition and check the Pre-sets in the beginning. While it is possible to change the project’s pre-sets later in the process, it comes with a bit more hassle, so one should be careful in what output pre-sets are chosen for the final product as they might interfere your effects done in the meantime.
Much like with Avid and Premiere Pro, you can then add media either by the path File/Import or by the shortcut keys Ctrl + I. However, if you want to keep your order and structure clear, you should first create a sound folder structure within your project panel before you import any media. This can be done by right clicking into the project panel, then clicking on ‘New’ and finally on ‘Folder’.
Finally, in order to bring media onto the ‘Timeline’ aka Composition Panel, you just drag and drop them into place. A green bar over the inserted clip or media item will indicate that the software has rendered this clip and can either display it at the right resolution or at the original speed (in case of videos). A blue bar (or bits thereof) indicate that this bit of medium has been pre-rendered and should – in theory – be able to play at original speed.
However, as After Effects requires a lot of RAM to work properly – and also depending on the effect(s) currently created, a rendered sequence might not be the standard. Thus, in order to know whether a clip or piece of media is displayed correctly, you can also go into the Effects Pre-sets, select the Preview tab, and then Playback settings. Here it will show you whether the inserted media are displayed correctly and – in case of a video – at how high a frame rate After Effects is currently playing the video.
Creating Masks – The Backbone of Effects
This is where it gets to the meat of After Effects – Masks.
Masks can be considered like stencils that are applied onto the medium of your choice. There are different types of masks that might not only entail the use of shapes – such as triangles and rectangles – but can also pertain to texts, manually drawn shapes, Rotoscopes, etc.
You can select a mask by clicking on New Composition and then Mask in the Composition Panel, selecting the desired type of mask there and then. Once you added it to the medium of your choice, you can then unfold an effects menu by clicking on the triangle next to the mask and change the mask’s property to your liking, such as position, point of entry, rotation, colour, etc. Furthermore, for each mask, you can set individual and multiple keyframes with different properties, thereby leaving it to the software how a certain effect can evolve over time.
Much like with Photoshop, you can then decide on the amount and order of masks, thereby creating a layer-like structure. You can then decide on the visibility of each layer, their interconnectedness to each other – in case of Null Objects – and whether they have their original effect or an inverted effect.
Null Objects
Now Null Objects were an interesting concept to grasp in the first place, as it requires you to think out of the box. A Null Object is essentially an invisible object placed either in or around the frame at a certain point in time, which allows you to layer various effects onto it. With a Null Object, you could e.g. create rolling credits that are not only filled with texts, but also with images and masks, each of which would follow the Null Object at the same time and – more importantly – speed.
It is essentially a good tool if you want to layer multiple effects and items and have them follow a certain path or protocol without having to painstakingly assign the same parameters to each and every effect you want to add.
Rotoscoping
This is another very important and helpful tool to have and to use. However, since explaining this would go way beyond the scope of this blog entry, I will write another blog entry of it in the near future.
Exporting a Project
Finally, if you want to export your project, you follow the path File, then Export and then Add to Render Queue. The software will offer you the Render settings in the Bottom Panel, in which you can subsequently decide on the output quality (best, full resolution, etc.) and the output mode (Quicktime if you want to re-import the clip back to Avid). Then, if all the required settings for your project are made, hit Ok, choose the desired folder and then hit Render. Make sure to always export clips with audio if required.
Things to Keep in Mind
Sadly, as with all other Adobe products so far, After Effects projects are usually upwards compatible, but not downwards compatible, which not only requires you to be careful in transferring AE projects into other AE software versions, but also requires you to keep a separate file of an AE project as a master copy.
Further Tips and Tricks
Depending on the specifics of your computer or laptop, the generally high demand of RAM when using After Effects might require you to play videos with a reduced quality in order to make it work on your engine. Thus, much like in Premiere Pro, you can decide to reduce the preview quality to 75%, 50% or even 25% in the bottom bar of the Composition Window. This, however, will require you to check your project back in a higher quality before exporting it to make sure that all is as it should be.
Furthermore, if you want to be able to work on your own specified workspace setup, you can not only save it as a pre-set via the path Window/Workspace, but you can also save it onto a memory stick and take it with you, being able to import and use it on a different computer and version of After Effects.
My Application
Although After Effects in its setup seems like an easy to understand concept – especially in regard to those avid to Premiere Pro – the concept and application of Masks, Null Objects, as well as Rotoscopes requires a bit of practice to implement and to use with dexterity and confidence.
For this reason, I settled on having a practice edit with the footage that we had taken from the audition for Teacher Central, thereby getting practice not only with the software, but also with green screens in general.
Because of this I furthermore wanted to check whether the green screen that I lit during the audition was of any use or whether I would have to redo my research and apply a different method before we start filming.
Thus, I started out by picking a video of my choice (here represented by its still image) and entered it into After Effects by the method described above:
I then applied the Keylight 1.2 Effect onto the clip by selecting it from the Project Panel on the right as described above, and adding it onto the Effects Panel as you can see here:
I then selected the colour picker tool under the tab Screen Colour and selected a shade of green from the depicted green screen that was neither a highlight nor a dark spot, and the image turned like this:
Now, since there are still negative shadows in the background (in this case the inverted image of the seam in the green screen), this was now the time to move into the finer adjustments of the Screen Matte functions, namely the Clip Black and Clip White functions as depicted here:
As you can see in the image above, these values are rather high for both values. While this is not a problem for the Clip White function – the standard recommendation is to keep it as close to the value 100 as possible – the value for Clip Black is quite extreme, as it is centred almost to the boarder between the two – when it is recommended that it should rather stay close to 0. However, after changing the stats to it, the background of the image looked a lot clearer:
After I had done this, I went onto the Internet for an example image in the matching resolution and fed it into the software. Hereby, I needed to make sure that this image was layered underneath the masked clip that I just created in order to make the effect work properly. This was the interim result:
But because the colours and especially the saturation between the inserted background and the masked image were clearly off, I decided to attempt a quick colour correction to the masked clip by the application of the Colour Levels effect:
As you can see in the histogram above, I experimented a bit with the Input Black and Input White of the masked clip, as our actress was a bit bleak compared to her surroundings. With the Input Black value at 44.0, the composed image thus looked like this:
A bit too harsh and contrasty for my taste. Which is why I experimented a bit more and took the Input Black levels down:
And suddenly came into a much more befitting colour spectrum:
In this image, I had also skipped through the clip to see whether the intended effect was the same everywhere in the clip or whether I would have to adjust it even further to make it work in every second of the clip.
Finally, in order to avoid that dreaded ‘stepping’ effect that can occur in the area of the head where the hair is layered with the green screen, I slightly changed the Screen Softness (that can be found under Screen Matte) of the image to 4.4, leading to this effect:
And this is the final result of my editing practice:
The usual recommendation for incorporating After Effects into the workflow of Avid and DaVinci Resolve would be sub-clipping the clips first in Avid, then adding the colour correction and colour grade through DaVinci before finally adding the effects onto the clip in After Effects and reimporting the clips back into Avid for the final export. However, since this was just a quick test, I decided to skip DaVinci for now and experiment with After Effects first, thereby also experimenting with its own colour correction options.
However, this will certainly not be the last time I experimented with After Effects.
References:
braproductions (2012) How to Color Correct/Grade in After Effects! [online] https://www.youtube.com/watch?v=A0xL16G0Kjs&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&index=47&t=0s [Accessed on 13 March 2019]
ECAbrams (2011) How to Chroma Key (green screen) - Adobe After Effects tutorial [online] https://www.youtube.com/watch?v=Goq7vmhOYy0&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&index=49&t=0s [Accessed on 13 March 2019]
Frikanih FX (2016) Professional Green Screen / Advanced Keying Tutorial [After Effects] [online] https://www.youtube.com/watch?v=MPKwKVyJWB4&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&t=0s&index=44 [Accessed on 13 March 2019]
Jason Levine (2017) Easy Green Screen Keying in After Effects CC [online] https://www.youtube.com/watch?v=idgFCsnxa5U&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&index=40&t=0s [Accessed on 13 March 2019]
Surfaced Studio (2012) How to Avoid 5 Common Green Screen Mistakes - Visual Effects 101 [online] https://www.youtube.com/watch?v=6lSZr1BInl0&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&t=0s&index=41 [Accessed on 13 March 2019]
Videomaker (2012) Fixing Uneven Lighting and Unwanted Objects for Green Screen [online] https://www.youtube.com/watch?v=qbLtDizQ-o8&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&index=42&t=0s [Accessed on 13 March 2019]
Yiannis Stravolaimos (2016) Green screen compositing and color matching. [online] https://www.youtube.com/watch?v=SZDlNYnR1Dw&list=PLRG4t0YYtkIzejIqbZ-qKOLjQchEri9ev&t=0s&index=52 [Accessed on 13 March 2019]
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