Optical illusions are a lot of fun, particularly when they’re based on colour. Ones such as this, posted by Dean Jackson on TikTok, is a great one that shows how our brain tricks our eyes into seeing colour that isn’t really there. This particular video starts off as a black-and-white image of a lady which then has a red filter placed over it, except for the eyes. Suddenly, we now see her eyes as blue.
Except they’re not really blue. They’re still grey. Our brain has tricked us into thinking that they’re blue based on the warmth of that red filter. It’s an interesting quirk of our brains that allows us to see beyond colour inconsistencies and fill in gaps for information that isn’t really there. A quirk that has real implications for photographers and filmmakers, especially when it comes to colour correction.
The phenomenon, as Dean explains it, goes like this:
Your brain detects the pigment, the grey area around the pupil, and it assumes that the red filter has trapped the blue light. So, it tries to help you out, as your brain should, by putting the blue colour back into the picture for you in your brain, completely misleading you in the process.
After showing the image in black and white, and then again with the red filter over it, he introduces large blocks of grey to show that there really is no blue in the image at all.
The video serves as a great example of why we should calibrate our computer monitors when editing photos and videos. If our monitors aren’t showing the correct colours, our brain can compensate and make them appear right when they’re not. Then, when we send them off to a printer, they look nothing like the way we thought they would. But it goes beyond just having an accurate screen and into colour harmony. It’s why skin tones can appear to be the correct colour – or the wrong one – based on the colours of things around them (or around the rest of our room, as editors), even though the opposite is true.
Dean, who goes by @beatonthebeeb on TikTok, regularly posts new optical illusions. If you’re interested in optical illusions and how the brain can be so easily tricked by imagery, it’s well worth checking out his feed.