Building a Greenscreen Cyclorama at EASV

Greenscreen Cyclorama Construction

Cyclorama done and in use

Cyclorama done and in use


I am working as a teacher at a school in Denmark, where we educate new multimedia designers and bachelors in web development.

As part of these educations the students need to learn how to use new media and technologies.

In that frame of mind, we wanted to give the students more professional looking facilities to work with video production and visual effects.

Therefore we chose to build a full Greenscreen cyclorama.

I will in this article describe the path we took building the cyclorama, and some of you might find this useful in building your own Greenscreen cyclorama.

Planning and preparation

We started out selection one of the older classrooms, which already needed restoring.

The classroom had a dimension of 8 x 7 meters (56 m2) and 3.5 meters high.

I then created at 3D rendering of how we wanted the Greenscreen to look after it was done.

Greenscreen Cyclorama 3D rendering 01

Greenscreen Cyclorama 3D rendering 01

Greenscreen Cyclorama 3D rendering 02

Greenscreen Cyclorama 3D rendering 02

As I knew there was no way I could create/build the cyclorama myself, I contacted several entrepreneurs, to give me an offer on the cyclorama construction.

After some back and forth, we found our entrepreneur, and started planning the construction (selecting materials etc.)

Reinforced Masonite plates

Reinforced Masonite plates

One of our biggest concerns was durability and sturdiness. This cyclorama should be used by hundreds of students over the years, and would have to stand the test of time and abuse from students.

Together with the entrepreneur I chose reinforced Masonite plates which (if we use two of them) could be molded and formed into the curved surface of the cyclorama.

The corner is and always will be the tricky part of a cyclorama. Primarily because it has to be formed very specifically, so that it creates a nice curved surface in every direction of the corner.
We talked about a lot of different materials for this corner, Wire mesh, Masonite, Glass fiber etc…
At the end we agreed upon papier-mâché as a base form, and several layers of epoxy resin to make it durable and water resistant.

The walls and floors should be Medium-density fiberboard (MDF) and Chipboard.

Construction

The really good thing about using papier-mâché is that it is really easy to mold into form. The plan for the corner was to take a gymnastics ball (ø=100cm) and put papier-mâché all over one side of it, to create the curved surface. We used several layers of papier-mâché and glass-fiber bands of tape to make the form more durable and sturdy.

This is how the mold looked after the gymnastics ball was deflated and the mold completely dried out.

Paper-mâché mold 01

Paper-mâché mold 01

Paper-mâché mold 02

Paper-mâché mold 02

In the old classroom we started out putting some wood planks on to the wall for later mounting of the MDF boards and support structure.

Wood planks on the walls

Wood planks on the walls

All the curved areas got MDF “ribs” to make the construction more durable and solid. These where cut out from 3 cm thick MDF boards and have a radius of 55 cm.

Ribs mounted to the wall

Ribs mounted to the wall

The corner was done in multiple steps. First a peace was cut out from the papier-mâché half-ball mold. Than this basis of the form was screwed onto three of the MDF ribs, where after this combined element got screwed onto a floor MDF panel and the top and sides got reinforced with panels of chipboard, hereby giving it a lot more durability.
The reason we used a floor panel, is that the entire floor should be covered with 2.5 cm thick chipboard plates, and the corner therefore had to be lifted that amount to be flush with the floor.

Corner box from the front

Corner box from the front

Corner box from the back

Corner box from the back

This corner box element then got screwed onto the wood plank on the walls, to secure it tightly.

Corner box secured to the wall

Corner box secured to the wall

The Next step was to secure the MDF ribs to the wall (along the floor, and along both walls in the corner). This was done using a wood plank, and some corner brackets

Ribs and support structure

Ribs and support structure

Diagram of support structure

Diagram of support structure

Now with everything more or less in place, we could fit the curved surfaces.
These where made of the reinforced Masonite plates which were put on top of each other and glued together, hereby molding and forming them into the curved surface of the corners in the cyclorama.

Curved surfaces

Curved surfaces

These curved elements got screwed onto the ribs along the walls and in the corner.

After the corners/curves where installed, we fitted all the MDF and Chipboard plates to the wall and floor.

The floor chipboard plates have a special beveled edge, which means that they can be click and glued together for added stability.

Wall and floor plates 01

Wall and floor plates 01

Wall and floor plates 02

Wall and floor plates 02

Because of all the joints, the cyclorama still had a lot of uneven surfaces, which needed to be flattened out.

The papier-mâché corner also needed to be treated with extra materials so that it would be water resistant and more stable/durable. The papier-mâché corner got treated with epoxy resin, with some added gravel material to make it harder.

Now the painter took over the job of flattening out the joints and making the walls and floors ready for paint.

He started out by coating the whole cyclorama with a base paint, to make it easier to glue fiber cloth onto it later on.

Then he started applying strips of fiberglass tape to all the joints, where after he used plaster filler to even out the joints. He also used plaster filler in the corner, to create an even surface.
After all the filler was applied, and died out, he sanded down the hardened plaster, to create a smooth surface.

Paint base coat

Paint base coat

The next step in the process was to add fiber cloth (large sheets of think paper). He glues the fiber cloth to the entire surface (a bit like setting up wallpaper).

Coated in fiber paper

Coated in fiber paper

Then again he used plaster filler to even out the joints of the fiber paper, where after he sanded the hardened plaster.

The final step in the process was now to paint the whole thing green, but this created a small dilemma – Which specific green color should we use?

Color / Paint

I had to figure out which specific color to use for the green screen cyclorama paint. Having never done a Greenscreen before, I turned to the web for help. I found a lot of pro-paints that you can buy (E.g. Rosco paint), but I would end up using a lot of money on paint alone. My painter could supply me with all the normal hardware store paint I needed, but I just had to figure out which one.

Our school had a copy of Hollywood camera work – Visual Effects for Directors (http://www.hollywoodcamerawork.us/vfx_index.html), where one specific subject actually was about getting the right paint, but from a hardware store.

I used their method to test out which of the sample colors I had obtained would be perfect for my Greenscreen.

The basics of the method entails getting a picture of you sample(s) with the camera and lighting you will be using, and then separating the Red, Green and Blue channels to see which sample has the most green (brightest in the green channel), and the least Red and Blue (darkest in the Red and blue channels).

Color samples used

Color samples used

The color I ended up choosing is called Flügger 1508 from the “Flügger 900 farvevifte”.

The painter then coated the cyclorama in five coats of very matte paint (Glans 5), and the construction of the cyclorama was done.

 

 

 

Cyclorama done

Cyclorama done

Lighting

I knew from the start that I was going to use continuous lighting for the cyclorama, primarily because we should be able to shoot videos in the room. I also wanted lights that would not become extremely hot, because of fire hazard, but also because this would make the room very warm/hot to work in (in longer periods of time).

I looked at the two alternatives to halogen and incandescent lamps which are LED’s and fluorescent tubes.

All the LED panels I could find, didn’t have enough output, or where to expensive.

I decided on florescent banks, but did not want to pay huge amounts of money on Kino Flo Diva lights, so I looked at some cheaper solutions. I found a product from British Interfit Photographic which is called CoolTubz, and I could get them for a reasonably okay price from a UK retailer.
Interfit also had some fluorescent spot lights (Super Cool Light 9 MKII) which I also needed.

The five CoolTubz banks where mounted to the celling, and the four spot lights were placed in the room.

Cyclorama done and in use

Cyclorama done and in use

This concludes my “guide” on building a Greenscreen cyclorama from concept to the finished product.

Om Kim Thøisen

My name is Kim Thøisen. I am a Bachelor in Web Development and a multimedia-designer. You can see my hole portfolio on this website. You can choose a categori in the menu, or check out the Selected articles here on the frontpage.