Important!
So, why do you develop prioritization of your 3D scanner using visible light? Here’s the main reason why: resolution. I’ve stated earlier that the goal of my 3D scanning project is to produce a high-resolution, low cost 3D scanner. And that’s precisely what you get by using visible light for the scanning. Sure, you can also use infrared laser light, it’s just that getting a camera that can see that is less convenient. And sure, you could try using radar if you wanted to, but due to the much longer wavelengths of light involved, you wouldn’t be able to get nearly as much resolution. And sure, you can also use sonar, but again, that comes with a problem of resolution. Ultrasound is a viable mechanism for high-resolution scanning, but ultrasound equipment comes with the problem of higher costs.
So infrared and visible light it shall be, and I will be primarily concerned with working in the limits of these media and technology. After all, if the primary purpose of the scanners is to produce imagery comparable to that which you would see with the human eye, there’s no point in going above and beyond the diffraction-limited resolution of red light when it comes to scanning resolution. So, that’s another good thing. We have practical limits on the maximum scanning resolution that would ever be desired of our objects. Diffraction-limited microscopic resolution, easy as that. And, surprisingly, you can get rather high resolutions using rather cheap optics on the side of your red laser, leaving the optical complexity to that of your camera. And if you use a DSLR camera, you can also get quality microscopic optics resolution with the right lenses.
The use of infrared light and cameras is mainly a strategic one. Some objects are opaque to infrared and transparent to visible, whereas other are transparent to infrared and opaque to visible. So, if you do have the option to use infrared light, this provides you with additional options for scanning the details of your objects.
20161203/https://3dprintingindustry.com/news/mit-silicon-photonics-research-breakthrough-3d-scanning-93892/