seanj wrote:
Prof Hank is a professor of Electrical and Computer Engineering and is fairly well known for his technical report on building a digital fisheye camera for under $20. I suspect he can easily see 3D because he wrote this report here for regular people and it's directly about traditional 3D (e.g., as in glasses): https://www.instructables.com/id/Use-Your-Camera-To-Capture-3D-Anaglyphs/
I guess I tend to believe Prof Hank more than anything because the concept is still, at this time, yet to be explained in the scientific literature . . . it's simply a concept that some of us want to believe because some images look 3D for some users, but I can go on Flickr and find plenty of captures with the same lens and camera that doesn't have the 3D look. Post processing probably comes into play (e.g., adding saturation and contrast, perhaps) and certainly the light and scene are even more important. I'd love to be convinced to believe with a controlled test, though. ...Show more →
Oh, I'm sure he is a brilliant fellow.
That said I am not sure how how modifying a camera to create anaglyphs would make one an authority on what we are discussing but I might be missing something.
Are you sure it hasn't been explained? To know for sure we would have to do an extensive survey. More likely than not we would find that a substantial part of the answer lies in a physiology journal rather then an engineering one.
Look - we all know that all of the images above are equally flat. No debate there. It is also quite apparent, at least to some of us, that some of those images create the illusion of depth while others do not.
I'm sure it is a combination of elements including working distance, subject, subject to background distance, light, aperture, and optical design, that come together to produce this illusion.
Change one component even a little bit and it might not be there at all.
Additionally the viewer has to have the physiologic ability to appreciate what the image offers.
An introduction to a thousand people that can't see it does not negate its presence.
As a reference:
Absolute pitch is only available to 1 in 10,000 people.
That means that there are 9,999 people that might tell us that "it's all in your head" based on their "experience".
How about optical illusions? Some people can readily flip back and forth between the cat and the old lady.
Others cannot and will insist that it is only one or the other.
In any case I guess I'm one of the lucky ones that has the ability to discern these differences.
I've seen the effect from a number of different lenses including the Zeiss 35 ZM 1.4, the Zeiss APO Sonnar 135, the Sigma 135 and also the Canon 200 F2. here is a shot from the APO 135. Sometimes it's a combination of super sharp subject with a distance separation to the background and sometimes it isn't. Zeiss APO 135 Sony A7R by Jose Raposo, on Flickr
I agree that it's 3D-ish, but there is plenty of background blur, especially considering the depth of the scene. The rock right behind the bike parts is blurred.
MIRANDA1 wrote:
I've seen the effect from a number of different lenses including the Zeiss 35 ZM 1.4, the Zeiss APO Sonnar 135, the Sigma 135 and also the Canon 200 F2. here is a shot from the APO 135. Sometimes it's a combination of super sharp subject with a distance separation to the background and sometimes it isn't. https://live.staticflickr.com/7008/13478066025_adec15c49d_h.jpgZeiss APO 135 Sony A7R by Jose Raposo, on Flickr
Show me a picture where the background and subject aren't isolated from one another with 3D-ness.
For my eye and brain, 3D requires subject and background separation and a wide aperture.
DaveFP wrote:
Are you sure it hasn't been explained? To know for sure we would have to do an extensive survey. More likely than not we would find that a substantial part of the answer lies in a physiology journal rather then an engineering one.
yes, i actually am a neurophysiologists that specializes in sensory perception and learning. there are a bunch of specific cues that the visual system uses to extract depth, texture, and to bind individual features into the perception of a single object. you can read a rich literature about it that goes back more than 50 years in animal studies and more than a century in psychophysical studies of humans. sadly, the link to properties of high performance lenses has not been well explored and there does not appear to be any real consistency in photo forum users perception of what photos produce 3D (though there is a strong placebo effect) nor is there amongst lay viewers.
the truth is that your brain uses lots of different cues to extract perception of volume and depth and it is easy to bias factors an individual pays attention to towards specific cues. people on photography forums are typically talking about any number of 5 different cues, but different ones are talking about different cues.
sebboh wrote:
my apologies, i did not mean that 3D is an ambiguous term on it's own, I meant that it is a meaningless term as it is used photography forums. you will see if you look in the old posts in this thread (or the many others on this forum) that everybody uses the term differently and nobody can even remotely agree on what photos have "it" and what photos don't.
yes, i am familiar with the development of perspective and methods of providing 3D feel in art history.
I don't agree. If you throw out terms like "3D" and "pop" as "meaningless," then you'll have to throw out the bulk of descriptors used in any discussion. Creamy bokeh, flat images, rich sound, snazzy wheels, sexy person - all of these descriptors are clearly taken as being "in the eye of the beholder" and they definitely have meaning to those who use them. Your tossing out the terms as "meaningless" speaks more to your inability to see the qualities that so many others use and understand.
smpetty wrote:
Show me a picture where the background and subject aren't isolated from one another with 3D-ness.
For my eye and brain, 3D requires subject and background separation and a wide aperture.
I agree with you but I I think Makten's photo is a good example, here are two more examples of the "easy way " which speaks to what you are referring to. POP by Jose Raposo, on Flickr
sebboh wrote:
yes, i actually am a neurophysiologists that specializes in sensory perception and learning. there are a bunch of specific cues that the visual system uses to extract depth, texture, and to bind individual features into the perception of a single object. you can read a rich literature about it that goes back more than 50 years in animal studies and more than a century in psychophysical studies of humans. sadly, the link to properties of high performance lenses has not been well explored and there does not appear to be any real consistency in photo forum users perception of what photos produce 3D (though there is a strong placebo effect) nor is there amongst lay viewers.
the truth is that your brain uses lots of different cues to extract perception of volume and depth and it is easy to bias factors an individual pays attention to towards specific cues. people on photography forums are typically talking about any number of 5 different cues, but different ones are talking about different cues....Show more →
I was actually being a bit rhetorical. I have a zoology degree (among others) so I have had some exposure to this topic.
Not on your level of course but enough to know that the "mind" and body work in amazing ways to generate our perceptions.
I'm pretty darn sure that this topic is well covered in optical literature too.
Lens technology has been around since the 11th century.
I have to imagine that more than one PhD. candidate has touched on these issues along the way.
This is a subject that's been re-tread more than a few times, obviously. In one of those previous iterations, a member here, with an Otus, IIRC, posted two photos of a wall and steel staircase, one of them was completely in focus and still had the very strong effect. I'll see if I can dig it up.
[When I talk of 3D, I always mean full DOF 3D.] Light and happy circumstances play a big part, but you have to separate those incidentals from the role played by the lens and the viewing eye. In other words, for a given composition and lighting, which ones at a common FL do better and which worse? We spend time on which have 3D but so little on which do not, and a process of elimination can be very helpful. What do the 'good ones' have in common and what do the bad ones have in common?
Above at p5#14 was mentioned depth perception issues, which raises the biggest factor of all: the human eye and, most importantly, the cognition system behind it. Opinions vary so widely on full DOF 3D largely due to the differences in the ability of individuals to detect small changes in tone, color and contrast.
Imagine you are driving in heavy fog. Any piece of visual information is of greatly expanded value, and your mind immediately sets to assessing its rate of approach, its size and its definition. Actually sRT (or simple reaction times) are falling and good time series exist, showing this happening. Your life may depend on your ability to do these things well, and it is a big factor in aircraft and motorway crashes that occur from time to time.
I’m not saying optics doe t play a role, but your comment about your wife, and certainly Derek’s weighty response echo my own thinking on it. Our brains take visual cues from the image, she. The fall off of the image closely matches what are brain expects, we see 3D in the image. When it doesn’t we see flat. I think that’s one reason that predominately we see the discussion around 35-50mm with some outliers. Also why brenzier shots or fast wide shots work, as out version is a narrow cone of focus with wide oof areas. The image is mimicking what our brain expects. It’s plausible that depth perception is somewhat of a sliding scale depending on our vision, so some see it and some folks don’t really register the depth.
Therefore while optics can perhaps ruin the 3D effect, I don’t think they can create it. Lenses that exhibit more of it, probably just match the most common vision, or the way the majority of us “see.”
DaveFP wrote:
Hi Matt -
With all due respect to ProfHank:
The fact that he was unable to elucidate the characteristics in optics that contributes to "3D" doesn't mean that optics don't play a role.
Perhaps there are optical engineers at Leica, Zeiss, Nikon, etc., that would have no problem helping us come to terms with this topic.
Today there are thousands of first-tier researchers slaving away at Harvard, Princeton, MIT, Cal Tech, etc., in order to come to terms with as yet unexplained phenomena. Perhaps this knowledge lives in the future (IF, in fact, it is not available today).
With regard to 3D:
We don't really need people to "agree" or "disagree".
3D as an optical/visual phenomenon is best understood through facts rather than feelings.
That someone can't see it doesn't make it less real. My wife can't see 3D due to depth perception issues. Should we include her opinion in this topic?
One reality that can be hard to hear is that not everyone with expensive gear has the sense and sensibilities of artists.
Those with the best "eye" for such things make better mentors than those that don't.
I am, at best, a "capable" photographer but I have eyes that are very highly trained with regard to color and dimensionality.
As such I have no problem "reading" the relative presence or absence of dimensionality in an image.
The fact that "SonyBoy96" on DPR can't see it doesn't enter into the equation; at least not for me.
Wouldn't it be nice if Dr. Nasse could lend us a hand?
Quite interested if you’d expand on this answer, specifically the 5 cues, or if you have some good literature to start with.
sebboh wrote:
yes, i actually am a neurophysiologists that specializes in sensory perception and learning. there are a bunch of specific cues that the visual system uses to extract depth, texture, and to bind individual features into the perception of a single object. you can read a rich literature about it that goes back more than 50 years in animal studies and more than a century in psychophysical studies of humans. sadly, the link to properties of high performance lenses has not been well explored and there does not appear to be any real consistency in photo forum users perception of what photos produce 3D (though there is a strong placebo effect) nor is there amongst lay viewers.
the truth is that your brain uses lots of different cues to extract perception of volume and depth and it is easy to bias factors an individual pays attention to towards specific cues. people on photography forums are typically talking about any number of 5 different cues, but different ones are talking about different cues....Show more →
Recent post-grad research (which the authors had serious difficulty getting published) argues persuasively that modern humans are losing a range of cognitive abilities quite rapidly. The ones of interest here are color discrimination and spatial perception. This loss is associated with a long term decline in general intelligence (known simply as 'g' to intelligence researchers and evolutionary psychologists) but modern life must play a part: apartment living, pollution, declining rates of open air sports activities, lower rates of driving (soon, self-driving cars), rates of vision correction etc. These are strong selection forces at play.
You can hypothesize that these are good reasons why modern lens makers are pushing 'bokeh' lenses and why 'bokeh 3D' are so popular compared with even ten years ago, as the preferred common understanding of the term. Bokeh - a sharp near subject with a lot of background - is simply a better fit to the environment and even vision of many modern humans. Those 'small changes in tone, color and contrast' which are so enmeshed in the high regard many have for Zeiss lenses, are becoming less and less important as time goes by.
Large proportions of lens reviews are devoted to acute inspections of bokeh features like circularity of OOF highlight balls, rings, busyness, residues of aperture blades etc. It's not visible content though, it's a photographic artifact that is put under the microscope, something added to compensate for something taken away.
Look at Zeiss's latest high end Milvus and Otus offerings (and those of most other makers) - no one produces as their flagship lines very large f1.4 lenses with the primary intention of open field usage at f5/6-f11, do they? Most of the frames of most images nowadays look a lot like the fog drivers have to work through, but it's an artificial optical fog that never lifts, and it's the main use case for so many of the new lenses.
Here's the post that I was referring to with images containing that effect without leaning on DoF - images are linked, not embedded, and as they're not mine, I'm not going to take the liberty of embedding them -
denoir wrote:
Judging from this thread and others earlier, it looks to me like a lot of people consider simple shallow DOF to be 3D. I can't argue with that as there is no good definition or general agreement to what constitutes '3D', but I think it is generally unrelated to DOF. Yes, a moderately shallow DOF can help things along but often IMO it detracts from the '3D'.
I'll give two examples here, shot with Philippe's Zeiss 50 Planar, one at f/1.4 and one at f/5.6:
To me the f/5.6 image shows as much '3D' as the f/1.4 shot although the f/1.4 shot is easier to instantly read as '3D'. Had the DOF been smaller I think it would have detracted from it....Show more →
WhyFi wrote:
Here's the post that I was referring to with images containing that effect without leaning on DoF - images are linked, not embedded, and as they're not mine, I'm not going to take the liberty of embedding them -
Interesting - the stairs seem to have the same degree of "float" in both images.
