High Dynamic Range in a single photo wo. post processing?

Started Jul 28, 2012 | Discussions thread
Veteran MemberPosts: 8,373
Re: High Dynamic Range in a single photo wo. post processing?
In reply to Richard Biffl, Jul 28, 2012

Richard Biffl wrote:

That's an amazing illusion. I put the image in an editor to verify that the A and B squares are indeed the same shade.

But doesn't it rather belie your argument that the brain can't get the same information from an image that it can get from the live scene? The brain uses relative contrast for its cues in either case. It doesn't need to know how many light sources are illuminating the image, because it uses contrast, which exists regardless of the absolute intensity of the light source.

The checker-shadow illusion can fool us, but most images do not. That's because it takes more than simple contrast differences to cause this effect. In the checker-shadow, the fact that we see the illumination of the cylinder, as well as the fact that we have an expectation of what a checkboard should look like, both play into the illusion. In fact, you might be able to block most of the image, showing three squares, and still have the effect based completely on your mind's view of a checkboard.

This is similar to the McGurk Effect, where a video of someone making a "fah" motion with his mouth is heard as "fah", even though the actual sound played in the video is "bah" (which you can hear by rewinding, playing again, and closing your eyes.) See it here...

So when viewing a live scene, an unknown number of influences will affect how your brain ultimately interprets the scene. When viewing a monitor or a print, the majority of those influences are not reproduced, and so you see the image as recorded by the camera (kinda like closing your eyes on the McGurk Effect video.)


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