I am purchasing sensors for a project and this may be a very obvious question but I want to ensure my theory is correct before I buy anything.

I have a colour sensor which only detects the light that is entering the sensor and I need a laser which will emit a beam of light that will reflect off of a red surface.

To do this I am planning on buying a red laser which will reflect off of a red tape and enter the colour sensor to indicate the colour red is above. Is this possible with the equipment I've mentioned above?

The distance between the tape and sensor is about 600mm.

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    $\begingroup$ You probably want to understand the difference between specular and diffuse reflection, and think about which kind your tape is producing before you get too far along in this project. $\endgroup$ – The Photon Oct 14 '16 at 5:18

Yes, that should work: red lasers should reflect off of red surfaces.

The only exception would be if your red tape had a funny absorption band right at the laser frequency. This is hypothetically possible because red isn't just one color but a range of frequencies of which the laser is a tiny sliver. It is very unlikely that you could accidentally get a piece of tape that would look red but not reflect your laser.


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