Contrast Gain Control Illusion

Contrast Wave Optical Illusion
Contrast Wave Optical Illusion

I’ve posted an interesting animation below, one that loops indefinitely between two simmilar pictures. Before you start, I’d like you to wait few seconds before the animation loops to it’s start. You’ll know it when you see left image blurred, and the right one in high contrast.

Ok, once you’re set gaze for a few seconds at the fixation cross in the center of the two neighboring images. After 10 seconds two new halves will appear, and I want you to judge the contrast of these halves.

What did just happen? At first, the difference between two halves was more than obvious – one was blurry, and the other one sharp. After the change, on the left part you initially perceived high contrast, and on the right noticeably less contrast. The right one became somehow darker, am I right? This effect persists only for a few seconds. After a while (moving your eyes around the picture should help) it becomes apparent that the 2 new halves are both identical. All of this has something to do with Contrast adaptation and Contrast gain control, but let’s leave this to someone more qualified – I’m sure there are many of you out there smarter than me. Don’t hesitate to share your explanation!

wave adapt optical illusion

53 Replies to “Contrast Gain Control Illusion”

  1. Neat!left is blurred and right is high contrast,after ten seconds both are high contrast but if u had stared at the cross in the middle the right would seem blurry and left high yet Vurdlak!BTW how can i submit my own optical illusion?ill have a look round the website to see if i can find out.but if you can help me that would be great.thanks anyway!

    1. what he ment is just watch the x in the center. after the one is blurry and the other is at full contrast, then when it changes and you are still looking at the x the one that was really blurry is better looking than the one on the other side, when in reality they are the same contrast.

  2. If you cover the image on the left with your hand it is more noticeable that the image on the right does in fact become more intensely colored. When looking at both, as both images are changing at the same time some will notice that their brain assumes that one image is not changing because it change is less of dramatic change to them, in my case it is the right.

    1. If you don’t focus on the x while you watch, it’s easy to see that the pictures are indeed the same.

      I was having fun watching the picture slowly return the right pic to normal before it switched back.

  3. When I covered the left image completely I could still see changes in “brightness” in the right image. I am not sure it’s an illusion but the change in the left image may be directly affecting how the monitor presents the right image. I notice a similar phenominon when the refrigerator turns on, the lights in my kitchen dim. Maybe its not an illusion but a quirk with the way monitors work?

  4. This is a .gif file. A web developer can build animation in the background when creating a .gif. Animation will display only when viewed in a browser (IE, FireFox, MacOS, etc). It won’t animate when viewed with a photo viewer. Save to desktop then open with a photo viewer…nothing! Then OPEN WITH..IE…voila! Clever but NOT an illusion.

  5. that’s quite and intriguing image there. I think it’sbecause your brain sees one blurry and one high contrast so when the left one becomes high contrast your brain assumes that the left one also switched and is now blurry but with further investigation your brain realizes that it is worng…but I don’t know if I’m right…just my theory…

  6. If you look at it through a few cycles, the high contrast keeps flipping sides when the images snap from equal to unequal, but if you just let it do its thing while you’re not paying attention, you’ll notice that the high contrast is always on the right.

    That’s a neat illusion. :)

  7. First, the left one is blurry and the right one is of high contrast. Then, they’re both the same, with lower contrast than the previous right one but more contrast than the previous left one.

    Maybe because the left one is of higher contrast than before, and the right one is of lower contrast than before, we see them as relative to what they were before.

  8. hit the stop button while the picture is still fuzzy – it stays that way

    refresh screen wait until the picture becomes clear, hit stop button, it stays clear

  9. if you cover the one on the left with your hand…the one on the right changes from darker to lighter even without the other one. Its fake

  10. the picture on the right… does lose some of it’s high contrast when the image on the left comes into focus, is Vuldark thinking the right picture doesnt change but we perceive it does?, bacause, i can guarantee when the left picture changes, the right one does become “less bright”.

  11. You are correct the right pic does change, however when it does changes so does the left one…at this point they are the same images. now wait til you see the left (blurry) and the right (sharp)….gaze at the X in the middle of the pics….now the pic’s change to the same image on both sides, if you are still gazing at the X you will notice the left image has a better contrast…this is all an illusion/mind trick…as you blink and look around the pics you will see that they in fact are the same contrast.

    Reminds me of the science test we did in middle school. Get 3 large bowls, place the bowls in front of you 1 – 2 – 3 In bowl 1 put ice cold water, in bowl 2 put cool water and in bowl 3 put hot water (not to hot as you do not want to burn your hand)….now place your right hand in the warm water and your left hand in the cold water…leave in for about 3-5mins. Then place both hands in bowl #2….you will notice the hand that was in the hot water will feel cold and the hand that was in the cold water will feel hot.

    This is the same mind trick using the sense of touch instead of sight…

  12. It’s not bogus. I think some folk just didn’t get what they were supposed to do. (I didn’t at first either.)

    When the picture on the left is blurry, stare at the cross in the centre.

    Keep looking at the cross as the pictures change. The one on the right is supposed to change as well. When you’re looking at the cross in the centre, the image on the left appears brighter and sharper than that on the right. If you take your eyes off the centre cross, however, it is clear the two pictures are identical.

  13. I would like to know if anyone that is saying this is not fake has tried the image outside of a web browser. It was pretty easy for me to download the image to my desktop, look at it in Windows Paint and retry getting the effect. Its not like I don’t see the “illusion” when its posted here its that I can’t get it to happen elsewhere. Let me know if the same process leads to a different result with different people or the same one as I had.

  14. the only reason we see this is because it takes a few seconds for our eyes to adjust to the change of light, just like when you are in the dark, and can’t see anything for a minute, your eyes adjust to the darkness. our eyes need time to adjust so that is why if you look at the x in the middle instead of each individual picture you will see what the “illusion” actually is

  15. I only have a right eye. When I stare at the cross and the change takes places, the two pictures actually switch; the right one becomes a complete blur like the left one had been. As long as I stare at the cross they continue to switch.

  16. i think it’s more of a gif thing, even if you don’t notice the difference between the contrast of two images, they change on their own

  17. Are you cats trying to say this isn’t an illusion really that dense? Yes both images change at the same time via .gif but that’s not the point of the illusion. Several people have already explained what the illusion actually is so I wont waste my breath. The point is it does play with your eyes and if you follow the directions the images you end up seeing in your minds eye for a brief second aren’t really what is on your screen at the moment. Just figure it out.

  18. Cover the image at the left with your hand completely. It’s not an illusion. The image at the right and left change. It is NOT an illusion.

  19. This IS an illusion. There are actually four pictures. Left one blurry, right one very high contrast. Then left one normal contrast the same as the right one. If you stare at the cross while you have blurry and high contrast on the screen, when it switches, your left eye perceives a high contrast picture and you right eye perceives a blurry picture. It is actually your eyes playing games. Trying to adjust to the differences. Then after a while you actually see what is really there. It IS exactly the same as the hot and cold water experiment.

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