Critique: 2 Research and Analysis(Technical) #2

ii) Surface Materials
Surface Material that can be use as surface is Tempered Glass or Acrylic Glass. If I use Acrylic Glass, I need a thick enough(more than 6mm) surface so it does not flex when pressed (to avoid short-term hotspots becoming blobs).

Acrylic glass. Image via here.

I will be using Acrylic Glass for my project because of its durability and also availability.

iii) Surface Diffuser and Projection Surface.
I also need some kind of surface for projection and diffusion. People have used vellum, tracing paper, fabric interfacing, and even cheap plastic tablecloths or shower curtains on top of the surface, in addition to frosted glass or acrylic. Before purchasing a frosted material and/or diffuser I have to test the surface’s suitability both as a projection surface and as an IR diffuser.

I have not decide what kind of projection surface to use yet because it's involve some experiment. I probably will use tracing paper simply because it's cheap.

iv) Projector
The use of a projector is one of the methods used to display visual feed-
back on the table. Any video projection device (LCDs, OLEDs, etc.)
should work but projectors tend to be the most versatile and popular
in terms of image size.

One thing to consider with projects is brightness. It’s measured in ANSI lumens.
The higher the number the brighter the projector and the brighter the setting can
be. In a home theater setting you alway want a brighter screen but in a table setup it differs.

One of the biggest limiting points of a projector is the throw distance. This is the
distance that is needed between the lens of the projector and the screen to get the
right image size. For example in order to have a screen size of 34in, then you may
need to have a distance of 2 feet between you projector and the screen. Check to
see if your projection image can be adjusted to fit the size of the screen you are
using.

Since my installation going to be around 36inches height, I need to use Short-Throw Projector to get a bigger image. This is the website to calculate projector dimension.


A short-throw projector. BenQ MP515ST Projector. Price around RM2000. I need a sponsorship! Image via here. View the specification here.

Reference
http://www.acrylic-in-china.com/images/cast-acrylic-sheet-007.jpg
http://www.digitalprojectorshop.com/images/MP515%20ST.jpg
http://nuigroup.com/forums/viewthread/7139/
http://nuigroup.com/forums/viewthread/1119/