Angry Photographer proves the 105/1.4E isn't "flat"

Started Oct 4, 2016 | Discussions thread
Just Tim New Member • Posts: 11
Re: Is an apology required for being a realist?

Marianne Oelund wrote:

Iain G Foulds wrote:

... Marianne: Seriously, you don't see depth in subjects, apart from the composition as a whole? In a portrait, an ear doesn't seem further away than a nose?

In that particular case, there is a manufactured sense of depth which only results from conscious recognition of the subject, and knowledge of what the subject is like in 3 dimensions, from prior experience. Light and shadow can help this, but at no time am I confused into thinking I am looking at anything remotely as realistic as an actual 3D subject. My binocular vision insists powerfully that I am looking at a flat surface (display or printed photo), and no conscious process can override that.

Now, if I close one eye and stay still, my mind becomes free to interpret as it pleases: Looking at the application windows on my monitor, I can certainly make them appear separated in depth, and I can fool my perceptions into believing that the stars on my background photo are as remote as real stars. But as soon as I have both eyes open again, everything immediately snaps together into a flat surface.

What I am trying to make clear, is that there is a huge difference between knowing depth from mere inference, and seeing depth through binocular-difference processing. To me, they are not remotely similar.

No portrait has any cues in it, which would allow you to discern whether the photo was taken of a live person, or was just a photo of a flat photograph. Anyone who has done photo copy work knows this first-hand.

The consciously-derived sense of depth from a 2D image does not occur at the level of the visual cortex, and it is only a rough approximation (typically an underestimate) of the original subject's true depth features, with a high degree of uncertainty - not to mention a high error and omission rate.

No single 2D image gives the visual cortex any 3D stimulation. That is the only place in your brain where a detailed and accurate third dimension can be constructed, free of uncertainties and confusion.

If you were shown a photograph of a collection of unfamiliar objects, without cues such as overlap or shadow or defocus, you could not determine what the relative distances of the objects were. Many convincing "trick" photographs have been produced, which take advantage of this fact.

Not entirely so. A lot of photographers make the false assumption that what they see is absolute. It is not. In many cases it is a figment of the imagination, quite literally.

What we see and how we interpret it is not 'hard wired' into the brain but learn through experience. Bi-nocular vision is only part of it. There are lots of small clues that we pick up subconsciously that allow us to place order and understand the world we see. For instance you understand distance because contrast and detail diminish with it. You can understand scale because you know the size of the cow in the field through your experience and memory of seeing it at close hand.

We do not see a fully sharp or colourful world with our eyes, in fact our range of sharp colour vision is actually quite small. Also we do not see with wall to wall sharpness. The image is not what your eye sees but is a construct of the brain which, to pinch a phrase or two, stitches and focus stacks the results of your eyes continually scanning the scene. Now this is an incredible amount of data, (your eyes have a greater resolution than your camera), and takes a short time to process. A very short time, but the effects are not so small.

Most of the time when we look at things, we do not see them properly. We just glance at them. When we just glance we do not always give the brain time to construct a complete image, and when this happens then our memory fills in the gaps based on how we've seen and understood similar objects in the past.

This is what a lot of photographers do, they don't actually look at things but just glance and make assumptions. A funny thing happens when we do that. We glance at one or two visual clues and force ourselves to associate them with what we want to see, the logic we wish to impose. We then become blind to any other way of seeing because we refuse to look any further or deeper into the object or image once we've seen in it what we want to see.

I know it sounds odd and almost unbelievable, but it's actually very easy to demonstrate:

You may think that it's a maths test, but all it really does is test how closely you look at something. If you just glance then you memory fills in the gaps, you see one type of flower and assume all the other similar ones are the same and cease to look any closer. When you do look carefully the maths is impossible to solve because the flowers in the last row are different to the ones above, (a single yellow instead of two, and four blue petals instead of five).

It is very difficult to add the visual clues into an image that overcome your bi-nocular vision when viewing images at close range, but one of them is linked to the reduction in contrast and detail with distance. You can do this with selective focus as the acutance naturally softens as focus decreases and is sharper in focus. This is not how we normally see things, we construct image in our brains that are in focus, but we associate the decreasing contrast and detail with distance. Now with some of your tests and well observed results you can understand that this is easier to do with some lenses than others. It is not the lens that creates this but an understanding of the effect through careful obsevation, actually looking carefully and not just glancing and making assumptions. This is the 3D pop. The best demonstration can usually be seen in flowing water on a long exposure. The water is light and lacks acutance against a far bank thats sharp and has deep blacks. In this case you can often observe the illusion that the far bank is actually in front of the water, almost floating above it. It's easy to confuse the eye not only when you remove the visual clues, but also when you jumble them up because it goes against our experience of how we've interpreted it in the past.

However even with this long ramble there will be those that do not wish to be converted or learn anything new. They will just glance at the words and only see in them what they want to see, make assumptions. The points they can argue against to convince themselves that their vision is absolute and what they think they see and the way the've labelled it is actual fact.

"No learning has any value if it leaves such habit undisturbed," and in a way you're banging your head against a wall.

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