Most projectors are usually designed to focus at a distance about 70cm~6meter, and their focusing range is less than 7% of the projector-screen distance. This means that if you place object at a distance of 1 meter, the projector can only focus for a range of 7cm (from 96cm to 103cm). But what if you have a object larger than "30cm x 30cm x 30cm"? Most of the object will be out of focus and the resulting mesh will be noisy and perhaps useless.
Also for scanning small objects such a coin, you need to place the object very close to your scanner, so your projector should be able to focus at short distances.So if you are interested in overcoming these major problems, continue reading the rest of this post
I created a tutorial video to show you how we can modify the lens of a projector to:1- increasing its focus range, that means maintaining quality of focus for more than 40% of the projector-screen distance.
2- getting focus at close distances, for example 15cm or less. This is ideal for macro scanning.
https://www.youtube.com/watch?v=oQGsH-z3sNo These two modifications are the most important and effective enhancements for the projector. And in future I will share more modifications for projector.
