R200 effective materials

[Thomas_5207]

Hi,

I am wondering what is everyone's experience with the depth data for the R200. For certain materials and colours, we do not get depth data. Is there a list of these materials anywhere, or what settings work best on these materials? If not maybe it would be good to collect our findings.

The obvious ones are dark shiny materials. Black glossy objects are very difficult to collect data for. But I even noticed I was unable to get data for hardwood that is a dark brown and has a shiny varnish. I was only able to pick up data from the lighter areas.

Sunlight has a large influence on data. I tend to use a low gain but a high exposure. Do people have better results with auto exposure generally? Worringly I was not able to get data from matte painted walls if they are coloured and have sun shining on them. I have better results with white walls.

[samontab]

All of what you are saying does not only apply to R200 but to any IR sensor in general.

Materials Science is the field that studies the properties of materials. You can research about how infrared light interacts with different materials.

Keep in mind that a material that looks black in visible light could have a different shade of gray, or even be transparent in IR. Or the opposite, as glass is opaque in IR but transparent in visible light. So, moral of the story is that you should not judge materials based on the visible spectrum for an IR application.

Always check your IR camera. If you are not getting depth because it looks too dark, you need more exposure or gain. Or maybe you are not getting depth because it is overexposed. The same concepts of normal photography apply here, including (IR) lighting control. You need to have a well exposed IR image to calculate depth. And continuing on that idea, you can even apply HDR concepts to depth generation, which is one of the things that I'm doing at the moment to get a more complete depth image.

Sunlight has a large influence on the depth image since it has a lot of IR light in it. It will dwarf any IR emitter you have, so even if you get a well exposed IR image, you won't be able to see the projected pattern on the object, so no depth for you with sunlight present.