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andrew whicker
10-18-2020, 1:16 PM
Hi,

This may be a stretch for a bunch of us no good woodworkers, but I couldn't find a good starting point for Google'ing.

This topic comes from the art world. I was re-reading modern art history movements and, of course, Cezanne comes up. For those that don't know, Cezanne is famous for 'painting with two eyes'. He spent his entire life trying to paint this way. To be honest, I've looked at a few of his works and I don't totally get it. The extreme of this idea comes thru with Picasso, who tries to show all sides of an object on one plane.

Regardless, it made me wonder why cameras use only one lens. Starting out with one lens make sense, but we have made huge leaps in technology and we are still choosing one lens. I'm wondering why. There must be a good reason for using only one lens instead of two. One would think we would want to re-create our vision instead of creating a kind of false vision.

Mike Henderson
10-18-2020, 1:53 PM
Actually, stereoscopy is an old technology that goes back almost to the birth of photography. Here's one description (https://www.futurelearn.com/courses/stereoscopy/0/steps/16686). The two lenses were generally spaced about the same as your eyes. You generally need a viewer to get the 3D image but I had developed the ability to look at stereoscope images and see them without a viewer (but it took time to get the focus). I doubt if I could do that any more.

It's fun to look at some of the old stereoscope images. The first time I saw one I was fascinated.

The same concept is used for aerial photography where they take two images a short time apart. Since the airplane is moving you get two views from slightly different spots. When you look at those pictures in a viewer the 3D is extreme. For example, a tree appears much taller than it really is, but that allows an analysts to see objects better.

Mike

andrew whicker
10-18-2020, 2:08 PM
Ohhh... the things with the lever on them to click thru the photos? I remember those.

andrew whicker
10-18-2020, 2:10 PM
So I guess the problem is that you can't combine two images into one like our brain? It's impossible to make one output with the two inputs... Hmm..

Thanks for the link and explanation.

andrew whicker
10-18-2020, 2:29 PM
Haha, I just bought a ViewMaster and some slides. I think they're a ton of fun to use and a good guest interaction / talking piece.

Dave Mills
10-18-2020, 2:47 PM
So I guess the problem is that you can't combine two images into one like our brain? It's impossible to make one output with the two inputs... Hmm..


I wouldn't say it quite like that. If you combined two inputs into one output image/thing, the issue you have is what are you expecting to view it with? TWO eyes? A single eye? A direct tap into your brain? People have tried over the years to create one image that, like Cezanne, can be viewed with two eyes and somehow looks more real or 3D, and some folks (not me) are able to screw their eyes around to be able to see the depth in them, but mostly they fail because our eyes are in fact each expecting to see their own image, and not expecting to reverse engineer a simulation of 3D back into those two images, from which our brain re-combines them.

The ViewMaster, providing a separate image into each eye as they expect, seems to be the closest we can get to it, and stereo cameras with two lenses have been doing this for quite a while. Some new cell phones have two cameras, to my understanding, and are used to make these 3D images that seem can move as you wiggle your mouse or finger over them.

andrew whicker
10-18-2020, 3:19 PM
That is a good explanation and makes me feel better about not understanding Cezanne. I'm guessing for the effect to work with his works, for example, I would need to see his painting in person and from the distance (and location along the painting?) it was meant to be viewed.

I think painting is odd in a sense anyway. If I take in a view of a mountain with a valley in the forefront (take Cezanne's work Mont Sainte-Victoire which is an example of painting with two eyes) I would always need to paint one section of my view, move my eyes and paint a different section of the view, etc until I had a full painting. In other words, everything would be 'in focus' in the painting, but the reality is different. The view would only be in focus depending on where I looked, the rest would be peripheral. Maybe that is self solved in the painting due to the fact that a human is looking at it and therefore, the peripheral vision will be self corrected. Then there is depth and our ability to focus at different distances, an extra variable.

I'm probably not stating what I think very well, but it seems Cezanne's experiment was failed from the start and someone like Picasso really did a better job of it (which really came from African masks.. so maybe we should credit them). Picasso's paintings are wild, but they seem to resolve the 3D vs 2D issue by simply accepting that paintings are 2D.

Jim Becker
10-18-2020, 3:28 PM
Dr. Brian May (Queen guitarist and astrophysicist) is pretty into stereoscopic photography..

Mike Henderson
10-18-2020, 4:16 PM
Ohhh... the things with the lever on them to click thru the photos? I remember those.

That's a modern version of the stereoscope. The original, and the one used for aerial photo analysis, looks more like a pair of glasses mounted in a stand. The two pictures are placed under the stand so you can move them around.

Geologists use that system, also, to scout areas prior to an on-the-ground visit. When I was in college a roommate of mine was a geology major and use to do that in our dorm room. That was over 50 years ago. They must have better ways of doing it now.

Mike

Jim Koepke
10-18-2020, 4:36 PM
Haha, I just bought a ViewMaster and some slides.

Many years ago it seemed every scenic national park or tourist attraction's 'gift shop' had those slide wheels at the checkout counter.

Not sure if he is still into this but my brother used to collect old stereographs to be viewed in one of these:

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Many years ago there was a website with dozens of stereo images from the 1915 Pan Pacific Exposition in San Francisco in the area that now has the only building left from that time, The Palace of Fine Art.

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This was during the days of dial up and 56K modems. No one said when it is on the internet it is there forever. Just out of my photographic interest at the time over 50 of them were downloaded and given to my brother. He printed some of them to look at with one of his viewers. There were also a bunch of analagraphs. Those are the ones that use the blue & red glasses to view.

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It likely wasn't long after the beginning of the photographic process that someone started playing with the idea of seeing images like our eyes see them.

jtk

andrew whicker
10-18-2020, 5:55 PM
Dr. Brian May (Queen guitarist and astrophysicist) is pretty into stereoscopic photography..

That's an awesome resume.

Lee Schierer
10-18-2020, 5:57 PM
Back in the60's or early 70's there was a camera and process using film that took two images slightly off set from a single camera which could be printed that appeared to be 3 dimensional.

Kev Williams
10-18-2020, 6:07 PM
We need our two eyes to create depth perception, which greatly helps to gauge how far things are away. Using one eye, your main gauge of distance is object size.

Unless of course an optical illusion is messing with your brain ;)

the Ames Room:
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--have any of you with a Viewmaster scrutinized the differences between the left eye and right eye pictures? To get 3D cartoons to work, the artist has to draw 2 different versions of the same artwork to make the effect work. That must take some skill...

Speaking of skill and messing with your brain, I'm sure many of you have seen this street art chalk drawing?
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But have you seen this drawing from the wrong side-?
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3D perception, pretty crazy... :D

roger wiegand
10-18-2020, 6:45 PM
A few decades ago, before 3D rotatable computer models were easy, it used to be common for journals to publish stereo views of protein structures. If you held it at the right distance and crossed your eyes just so you could see the stereo image. It always made my head hurt. A steropticon works way better.

Mel Fulks
10-18-2020, 7:24 PM
I'd say Picasso handled it the same way the cartoonists do. When something is obviously a thing you don't recognize as
"real" you don't expect 3D. It's like Mickey Mouse....you just accept he has a flat face.
Having mentioned Mickey, I have to add his face is magical to children, Donald is way behind in popularity. No wonder
he's cranky.

Jim Becker
10-18-2020, 7:43 PM
That's an awesome resume.

Yes, he's very sharp. If you're on Instagram, follow him. He has a wonderful warm personality and posts about music, photography and helping others/causes. During the pandemic, he's even given free lessons to folks on how to play some of the guitar solos from Queen songs.

Roger Feeley
10-24-2020, 5:49 PM
A few years ago, there was the Lytton light field camera. While it wasn’t a 3d camera, it had a much neater trick. You focused the picture and set depth of field AFTER taking the picture. As I recall, you could also shift the angle just a little.

The company is gone but you can still find the cameras. I don’t know about the specialized software necessary to manipulate the image.

Jim Becker
10-25-2020, 9:59 AM
A few years ago, there was the Lytton light field camera. While it wasn’t a 3d camera, it had a much neater trick. You focused the picture and set depth of field AFTER taking the picture. As I recall, you could also shift the angle just a little.

The company is gone but you can still find the cameras. I don’t know about the specialized software necessary to manipulate the image.

Current generations of higher end smartphones with multiple lenses like the iPhone have this capability and it's very kewel to be able to dial in the depth of field one wants for effect.

Roger Feeley
10-28-2020, 3:23 PM
My apologies. The camera was the Lytros. Darned autocorrect!