Our example here wants us to dissect this graph a little bit more, and it says, using the figure below, estimate what wavelength of light would cause such a reaction, and say what color the person would be expected to perceive. So we're going to look at 3 different responses, and for each one it says roughly how excited each of the different cones would be, the s, m, and l cones. Then we need to estimate a possible wavelength and a perceived color from looking at this graph. So, a reminder on the graph, on the x-axis here, we have a wavelength from 350 nanometers up to 700 nanometers. And on the y-axis, we have the relative response or relative absorbance of those different photoreceptors, so how much response we get from each wavelength. And we have a curve for the s cone, a curve for the rods, a curve for the m cone, and a curve for the l cone. Now the rods, we're talking about color here, so we can ignore this line altogether.
First up, we have the response 1. It says the s cone is going to be highly excited, the m cone is going to have no reaction, and the l cone is going to have no reaction. So look at these curves. Where on the curves does that look like it happens? Because as I look to get no reaction from either the M or the L cone, that really only happens way over here on the left side in these shortest wavelengths. So to get high excitement from the s cone and nothing from the others, I gotta go right about here. Right? That's pretty high excitement, and that I'm going to estimate would be the wavelength. So what does it look like? About 390, we'll say. And what color would you see there? Well, you would perceive that kind of as a blue or a violet, I'm going to say.
Next up, we have s cone is going to have low excitement, m cone highly excited, and l cone mid excitement. So where do you see that? Low excitement for the s cone, high excitement for the m cone, and mid excitement for the l cone? Well, low excitement for s, so that's going to be in this region here. And we're going to be in the region where the m is really highly excited and the l cone is sort of mid excitement, that looks about there. So I'm going to go ahead and draw a line on this graph that it's going to be roughly there. That looks good. Maybe not quite a straight line, but you get the idea. Somewhere around there. So what wavelength could cause that? I'm going to say that looks like, oh, I don't know. How about wavelength 505 nanometers? And if your eye is hit with a wavelength of 505 nanometers, according to this graph, what are you going to see? The person's going to perceive something as green.
Finally, we have s cone gets mid excitement, m cone gets mid excitement, l cone gets mid excitement. Take a look at the graph. Where does that happen? Nowhere. Right? You can't have that on this graph, but that can happen. So do you remember what we said happens when all these cones are getting sort of a similar signal? We said when all the cones are getting a similar signal and it's really bright, that's white light. As it gets darker, it moves from gray to black. So because these are all mid excitement, I'm going to say that you're going to see a gray. And what wavelength are you seeing? Well, you're seeing many different wavelengths. It's not always that a single wavelength of light comes into your eye. Sometimes many wavelengths come in, and that's how we said you see colors that aren't perfectly on the spectrum.
Okay. So again, remember I said you may need to break down a graph like this? It's probably more likely that you don't. But I really think that breaking down graphs like this really helps you understand how your color vision works in terms of that relative signal from the different cones. Alright. Like always, we got more videos coming up. I'll be there. Hope you are too.