So i was doing some test with the different lenses that i got from Ebay, including the stock lens on the Philips SPC 900NC . I was testing to see the minimum height that the lenses could see a 12″ ruler at. I’m doing this because this will help determine how thin i can make my actual multitouch table. The results were very help full and i now know how tall i need to make my table.
The Results
These results are from the Philips SPC 900NC webcam just lying on the floor. The heights are all measured from the floor to the top of the acrylic.
Stock lens was able to see the full 12″ ruler at a minimum table height of 21 1/2″
8mm lens was able to see the full 12″ ruler at a minimum table height of 37″ (Multiply 3.08 x desired width of table)
6mm lens was able to see the full 12″ ruler at a minimum table height of 27″ (Multiply 2.25x desired width of table)
4mm lens was able to see the full 12″ ruler at a minimum table height of 22″ (Multiply 1.83 x desired width of table)
3.6mm lens was able to see the full 12″ ruler at a minimum table height of 18″ (Multiply 1.5x desired width of table)
These are just my results for the Philips SPC 900NC webcam with 8, 6, ,4 ,3.6mm lenses. They are fairly acurate, but i could be wrong.
an issue i did have with the 8, 6 ,4mm lens was that it had some focusing issues with the webcam. I could not get it focused completely at all. I could only get it focused enough so it wasn’t a giant blur, and the lens was barely screwed in.
So for my table i figure that the minimum height i can make it is 23″ which for my design is pretty good. I will probably end up making it around 24″ high. Now if i can find a wider angle lens i will be able to make it even thinner.
