To get the form right, so to show all angles of the object as much as possible, it needs to be lit from as many sides as possible as well. Therefor I thought I would need a lot of light and a lot of diffusion. So I got the flash out, put an umbrella in front of it and reflected it with a white reflection. I juggled around trying to get the best distance for the best light. But I wasn't happy with the results. Mainly because the reflector didn't reflect as strongly as I wanted, making the light not evenly spread, or the flash would be too close, giving highlights on the chair.
I decided to let the flash go off in front of the chair, in order to not get any shadows in the photo itself. I put the flash up on a cupboard that was standing behind me, and let it bounce off the walls and the ceiling. This was getting better. Bit dumb that I left the door open, so the light from the hallway was reflected on the chair!
I closed the door and was finally getting where I wanted to be. Apart that on the first light, there was too much reflection of the light on the image. So I changed the angle of the camera and the chair, so the reflection of the light would not fall on my camera sensor.
I am very happy with the result. The shape is really obvious and evenly lit. My son looked at it and thought it was cool to see that the chair was somewhat floating.