Green Screen (Chroma Key) techniques for classroom animation

I’ve been wanting a permanent green screen setup in class for a really long time now! For the last few years I have been using a polyester screen hanging off a wall mount with pegs. It was flimsy, always crumpled and never stationary. Plus with space constraints, I couldn’t dedicate a wall for the screen as every square inch of wall area is covered with posters and/or shelves.


With some kiwi ingenuity, my school custodian, Roland Boekhoff, came up with a brilliant idea of hanging a screen using an old roller blind which could be easily tucked away.

Old roller blind converted to a green screen.

The material for the screen would need to be a bit more durable and thick compared to the existing material I had. We managed to source a good quality fabric off Trig Instruments (who unfortunately do not sell that material anymore due to lack of sales).


Once we measured up the area of our screen and the roller blind, Roland got building. The end product is just awesome and works fine. Currently there isn’t an even source of lighting but we are working on some external lamps for the screen.

Leslie posing as the weather man
Mr.Leslie Stewart posing as the weather man

Meanwhile, with some spare green paper, I recycled old cardboard boxes for the Year 9 students to film smaller table-top scenes for stop frame animation project. I cut out two holes on the sides for the lights. The lighting is achieved by using clip-on lamps refitted with LED bulbs so that the set is lit up well without burning the screen boxes I am using     C920 Logitech Web cameras for filming the stop frame animation as that camera, I believe is the cheapest High definition camera which has manual focus ( very important for stop frame). The next part is the batch processing of images which is going to be tedious and boring. Students are looking into softwares for next year like green screen wizard and Dragonframe which can batch process with ease. Currently we are testing out Helium Frog animator ( and achieving mixed results. One student who brought a copy of Stop Motion Pro on his mac has been achieving good results and its ease of use is commendable. This project will take a term (2 lessons a week for ten weeks) from start to finish.


Stop Motion / Time Lapse Movie Making Activity ( Juniors)

Stop motion animation is one of my favorite topics to teach at year 9. It gives students a lot of freedom to imagine and storytell along with learning technicalities in basic movie making.


I have an interesting way to setup the stop motion theme. I picked up a box of assorted toys on TradeMe for $20 ( and keep adding to that box as and when I pick more toys up from various opshops) .

box of toys


Students are divided into groups on a random basis ( or using a random name generator available freely on the internet).


Each member of the group picks one toy from the toy box ( random order, maybe by keeping their eyes closed). From the toys they have picked, the next stage is to write out a script using those characters. The script will then be looked over by their English teacher for improvisations and errors ( Cross curricular opportunity ). Once the script is approved, they then create the storyboard.


To reiterate the importance of storyboarding I show the students this video from the making of Toy Story. ( ( 8:51 long) Students get a gist of the importance but may still need explanation of how much depth to go into. I usually have a collection of exemplars made by past students which I would use at this stage. They clearly show how much detail is expected.storyboard Sample Alternatively you could show pictures of storyboards made by students/professionals depending on how much detail you expect from them.

Next is filming. To understand filming ( in a short period of time) I split it up into Analysing and Practice. In the analysis, I show them video clips of movies with different camera angles. Each camera angle has its own advantage and can be used effectively at the right times. In the second part students use the camera to take a few shots of themselves and demonstrate their understanding of camera angles.

When they are confident of demonstrating understanding of camera angles, they can start working on their props. As my classroom is tiny with computers all around, there isn’t much of table space left. This makes the need for props to be compact if possible. Some students used office storage plastic containers (the ones available in Warehouse Stationery for $10 approx) to create their scenes which worked fine.


What camera to use? Through experience I have finally settled on something reliable and cheap ( not necessarily the most effective yet). I started stop motion using Sony Flip Cams(Bloggie). They take pictures at 12M @ 4:3, 8M @ 16:9 and 2M @ 16:9. They also come with a tripod mount which is highly essential for stop motion as you need to keep your camera steady. I next moved to some chunky DSLR’s because I needed manual focus for stop motion. But it wasn’t cost effective. I kept looking for handheld camera’s which had a manual focus feature but found just one ( was a Canon I reckon @ $400NZD).

My IT guy at school suggested to look at webcams and I came across a Logitech C920 which records HD and has a manual focus feature in its software. It also has a tripod mount screw which is perfect. Except for the fact that every picture has a countdown operating on the software which means a loss of valuable time. But nevertheless, it builds patience in the students 🙂


Editing software: Students use Windows MovieMaker at Year 9 which is ideal as it has a small learning curve. Accessibility of software and ease of use makes it ideal for this project. Students add filters of their choice to enhance their movies. Subtitles and credits are added to complete the movie. Stop Motion Animator, a Google chrome extension is also really good for making simple stop motion movies using webcams.


Advanced group: There will always be students who are more able than the others and it’s good to give them a challenge. In the areas of editing, students could try software like Adobe Premiere Pro ( you will need a license for it, but i highly recommend the student version as the Adobe bunch has some fantastic software which syncs up with Creative Cloud). Students can also try green screening their backgrounds as an advanced feature. Composition of music ( Cross curricular) to customize their movies using Sibelius or Garageband ( or tons of other free software on the internet) would be the next step.
Students can finally publish them to a channel they have made for this purpose or a class blog or a channel on Vimeo/Youtube/Schooltube etc. Make sure security settings are appropriately chosen based on what the expectations of the school are.