Limited depth - reason?

[milos.p...@gmail.com]

I am having trouble understanding why is there a limited depth since each eye is getting its own image. No other stereoscopic medium has that limitation and even anaglyph has unlimited depth. Am I not understanding something regarding how the light behaves through the lenticular sheet or is my calibration not precise enough?

[Giovanni Remigi]

Have you read this document?

http://kineticsystem.blogspot.com/2018/01/the-lenticular-medium.html

There is a section "Lenticular Depth-of-Field" which discusses the limitation of the lenticular medium. There is a mathematical formula to calculate the depth of field of a lenticular lens.

Because of the printing resolution, you can only print a max amount of pictures behind each lens, and beyond a given depth you will always experience discretization or jumping.

I haven't tried but I guess if you print two pictures it will behave like an anaglyph in terms of depth, but you will still have a limited viewing angle. In an anaglyph, no matter where you look from, one eye will always see the same picture and the other too. In lenticular, the image seen by one eye always depends on the horizontal position.

Cheers,

Giovanni

[Giovanni Remigi]

I forgot to mention. In an anaglyph, the depth depends on the viewing distance while in lenticular it is a constant (assuming you use a reasonable about of pictures).

Giovanni

[Michael Brown]

Each eye isn't seeing a single unique frame. When I have made 3D lenticulars with only two frames (left & right) the picture has the depth and clarity you would expect. (Very similar to using a 3D tablet. You have to hold it close to you and at just the right angle). In a 3D lenticular print with only two frames, the viewing distance and angle is so critical that such prints are difficult to view and not practical. Adding more frames gives a greater range in viewing positions. As you add more frames, you are optically averaging them which increases the blur. So in a 3D print with 24 frames, the right eye might see a blend of frames 9,10,11,12 and the left eye sees a blend of 17,18,19,20. Moving closer or farther would result in seeing other combinations with more or fewer frames being averaged.

[Dominique Mulhem]

I find it hard to understand why there is limited depth since each eye gets its own image. No other stereoscopic medium has this limitation and even the anaglyph has unlimited depth. Am I not understanding something about the behavior of light through the lenticular sheet or is my calibration not accurate enough?

With an anaglyph or any other stereoscopic mode we have almost unlimited depth.
With the lenticular the light passes through a lens which creates a disption of the light spectrum and passes through the lens a second time. This is why backlit lenticulars have better depth, as light only passes through the lens once. Lenticular screens have even more depth because they are illuminated by three lights green, blue and red which are semi-coherent lights. If a lenticular were backlit with a laser, it would have a very great depth.
At the time when I saw my friend Professor Maurice Bonnet, he showed me lenticulars with infinite depth, backlit with a system of his invention and in addition his prints were made with the Kodachrome 64 which had a more high definition than all known printers.

[Dominique Mulhem]

I still regret at that time, not to have tried with Professor Maurice Bonnet to make lenticulars with holographic film, Because the definition of the Ektachrome 64 is 100 lines per millimeter while the holographic film is of 5000 lines per millimeter.
For my relief designs I use the holography and the lenticular.

[milos.p...@gmail.com]

Thank you all for the information. This all makes sense. Now, if I understand, we could balance it by trading the number of views for more depth - if we need to fit a "thicker" object, lower the number of frames until the depth is right. It would jump more and skew the view but in some situations, it might be more desirable, if one can't afford highest-end printing, high-quality backlit, or any of the other mentioned fancy technologies. 

[Dominique Mulhem]

We could make a lenticular with two images, but we would have to stand at a certain distance and face it. Using multiple images allows us to see a lenticular from a wider angle and also a wider distance.