What if we could see the world like insects do ?

It's not impossible actually, it's surprisingly easy !

Some insect like bees are trichomat, just like us humans. It means they are able to differenciate between three different sets of wavelengths.

Humans have red, green and blue photoreceptors and trichromat insects have green, blue and UV photoreceptors. It's the same system, we're just not sensitive to the same wavelengths.

The human cone cells are usually not reffered to as the RGB cone cells, but rather as the LMS cone cells. These letters refer to the wavelegths not to the color and they are sensitive to. L stands for long, M for medium, and S for short.

Trichromat insects have LMS cone cells just like we do :

What if we tried to map the insects cone cells to those of humans ? Digital camera are sensitive to UV light if you push them a little bit.

The stack

For this insects vison stack we are going to use the ZWB3 which is a UV pass filter that also lets in a tiny bit of blue and green.

This tiny portion of visible light is enough to balance with the UV because the camera's sensor is very sensitive to visible and very poorly sensitive to UV. The filter passes IR as well so we'll be using a strong IR blocker, the TSN575, to block them out.

Here is a grating test :

As you can see UV is recorded in the RED channel which is somewhat counter-intuitive at first but that can easily be explained by looking at the white balanced RGB channels.

Since we want the S cone of insects to be assigned to our S cone we have to swap the channels so that UV ends up blue, the blue ends up green and the green ends up red. That way :

S insect = S human

M insect = M human

L insect = L human

You can do this in a channel mixer but a simpler way to do it is to apply a -120° hue rotation. That way the swap can be done with just one slider. Here it is : that is Insect vision :

That's how it looks like :

Do you notice that some objects are interestingly yellow ? You are going to see much more of that yellow !

Yes even warships, great camouflage.