A Cinerama Camera Possible in A:M?

[largento]

 

Several years ago, I bought the blu-ray of "How The West Was Won," one of the few movies shot in true Cinerama, using a camera with three lenses and magazines, able to record a 146° viewing area. These three strips of film were then projected by three projectors onto an enormous curved screen. The results were supposed to be spectacular. I've never seen Cinerama in person, but to simulate the effect, they mapped the movie onto a 3D curved screen and presented it on the blu-ray in what they called "Smilebox."

 

The effect is pretty spectacular.

 

Got me to wondering if a Cinerama Camera and screen could be simulated in A:M, so that you could end up with a Smilebox movie.

 

Not being very familiar with real world camera settings and how to translate them to A:M, I have read that they used 35mm film for each strip with 27mm lenses. Attempting to simulate what they human eyes see. The cameras were at 48° angles from each other, but they obviously had to be offset, since the three lenses couldn't exist in the same spot. The resultant image was 2.59:1 aspect ratio (although there's an optimum ratio of 2.65:1.)

 

Obviously, it would require three renders, but if they could be made seamless, then they could be assembled and mapped to a curved screen and rendered again as Smilebox.

 

The real Cinerama screens had the outer thirds of the screen made up of 1100 louvered strips that were rotated to face the audience. This was because of light spillage from the curve of the screen and the three projectors. I don't think this would be an issue if the final render didn't include shadows or any additional lighting.

 

The final film was projected at 26fps and there was some sort of interlacing that alternately overlapped the seams to make them less noticeable. Again, I think this wouldn't be necessary with A:M.

 

I think it could be neat to do a short in Smilebox, but I'm realizing I don't know enough about the camera settings to recreate it on my own.

 

Anybody got any thoughts/ideas on how to accomplish it?

 

 

[robcat2075]

I have actually seen Cinerama on a true Cinerama screen.

 

"This is Cinerama" was re-released in the early 70s and my parents and I went to see it.

 

It is a remarkable effect IF you are sitting in the sweet spot approximately where the curvature of the screen would be centered, which we made sure to do.

 

If you were far back in the theater you probably would see something more like the appearance of the "smile box".

 

The seam between the three filmstrips was always pretty obvious, especially when some object with straight lines intersected it, but for a lot of material it didn't matter.

[largento]

I'm jealous. I can only imagine what it was like for people back in the 1950s when it was new. Smilebox, of course, can't give that true wraparound feel, but there's something thrilling about seeing the sides of your vision go by. It was supposedly a nightmare to shoot with. If you wanted to have somebody on the left side of the screen talking to somebody on the right side, they had to stand on either side of the camera looking away from the camera ...and the person they were supposedly looking at.

 

Technical wise, I think it's still kind of shrouded in mystery. Everywhere I go, I seem to find slightly different information about the settings:

 

Cinerama employed a special triple 35mm camera set-up whose combined images covered 146 degrees [see photos above]. The camera aperture was 1.116 in./28.35mm high [equivalent to 6 perforations] x 0.997 in./25.32mm wide. The three 35mm prints were projected interlocked, from three separate projection booths, onto a deeply curved screen composed of 1,200 slightly overlapping vertical strips to create an image three times the normal width and also twice the standard height [the aspect ratio, as viewed from the center projector, was 2.06:1].

 

[robcat2075]

To do it in A:M...

 

I would note that the three-camera approach was compromise based on off-the-shelf lenses they had at the time. OmniMax is more modern attempt at the same effect. Today an OmniMax camera (not Imax) can cover the same field of view in one image and the OmniMax projector on the OmniMax screen (basically a dome) can approximately undo the distortion that result from putting that on one flat piece of film.

 

That distortion is what we see when we set an A:M camera to a very wide angle.

 

Idea 1) It should be possible to take that flat A:M render and re-map it onto a suitable rectangle then, with a pose, stretch and squeeze it in the right places to undo the distortion and create the curvature.

 

Idea 2) you can do three cameras just like cinerama and remap them onto a curved screen. Because A:M cameras can occupy the same point simultaneously there should be no mismatch between adjoining edges although there will be linear distortion at each seam.

 

Idea 3) Instead of three cameras.... many cameras, each set to take a narrow vertical slice of the panorama. Those could be mapped back onto a panorama screen. By using many narrower cameras you would reduce the curvilinear mismatch between neighboring slices.

[robcat2075]

Here's a quick test of a very wide angle camera in A:M. I used a lathed circle to place the vases all equidistant from a center point where I put the camera.

 

The distortion of the vases near the edge is obvious but also note that the radiating lines of the lathed circle appear parallel in the camera view (top).

 

It should be possible to remap that camera render onto something that could be stretched and squeezed and curved for a smile-box view.

 

[robcat2075]

Here is a bit more toying with the notion of using a pose.

 

the top is the original A:M camera render, mapped onto a rectangular grid. I think this distortion is called pincushion distortion.

 

The bottom is the same grid smooshed in a pose to negate the pincushion effect to make objects appear about the same onscreen size no matter where they are in the field of view.

 

[largento]

I'm not entirely convinced of the one lense process, since essentially, that was what cinescope and the like were. The distortion on the edges should only happen once the image was smileboxed, since there was no such distortion in the original image.

 

Here's what I mean:

 

 

Taking a wide shot and distorting it wouldn't be the same effect.

[robcat2075]

Taking a wide shot and distorting it wouldn't be the same effect.

 

 

 

What I'm doing is un-distorting a wide shot.

 

 

 

Would you agree that my A:M camera is at least taking a truly wide field of view similar to Cinerama?

 

CinemaScope could never take in that wide an angle of view. They didn't have the lenses for it and... a truly wide angle image needs to be shown on a screen curved to the same angle to not look completely weird. CinemaScope had only a slightly curved screen.

 

And would you agree that my Posed version at least eliminates the size distortion of the single lens image?

 

It's not complete yet, but those are the first two steps to get to a Cinerama-like image.

 

 

Here is the problem with three-camera Cinerama displayed in a flat format. Notice how the shoreline and the wavelines bend at every seam. That distortion is a problem for any straight line that is not exactly in the center like the horizon line.

 

The wrap around Cinerama screen is an attempt to re-wrap the image around the viewer to recreate how it was wrapped around the camera.

It didn't work completely, the distortion was still obvious on a Cinerama screen but somewhat less so because each third of the image was turned to face the centerpoint where you sat.

 

Also, Cinerama movies were planned to avoid horizontal lines that would cross the seam. There is very little linear horizontal element to that Debbie Reynold sample so distortion is not obvious.

 

Smilebox hides the bends a bit better because they are curving the interior of each third.

 

 

[largento]

So you're saying undistort it and then re-distort it with the smilebox?

 

The issue is that you are still starting with a flat view, so I do think you lose some of the actual sense of depth.

 

Here's an image where someone simulated what 2001 would look like on a Cinerama screen. You don't really get the sense that you are seeing to the sides and look how flat the figure on the extreme left looks.

 

 

Compare that to this image:

 

 

Still, though. Maybe I shouldn't worry so much about making it exactly right. If I use three cameras basically placed in the configuration and line up their cones, I should get three workable frames that I can assemble in Photoshop. Photomerge might even be something that I could use.

 

I'll have to play with it. It might be fun to revisit The Wannabe Pirates for a quicky short that uses this.

 

 

[robcat2075]

Here's an image where someone simulated what 2001 would look like on a Cinerama screen. You don't really get the sense that you are seeing to the sides and look how flat the figure on the extreme left looks.

 

 

 

They did a lousy job at that but you can't curve the "2001" image onto a Cinerama screen because the camera did not shoot a wide angle of view comparable to what a Cinerama screen presents to a viewer.

 

The woman in pink and the red couch on the edges of the 2001 frame are probably only 20-30° from the center axis of the camera. Everything in that frame is more in front of the camera than to the sides. Nothing in that frame can be properly placed on the side area of a curved screen that would wrap around you

 

On the other hand, the left and right edges of a Cinerama image are 70° off the center axis.

 

To actually sit in a Cinerama movie is not seeing something that truly looks like the smilebox. What you see is a wall that curves around you. The middle of the screen does not appear shorter than the sides because the middle is just as close to you as the sides.

[largento]

And yet, 2001 *was* presented that way. It's a Mad, Mad, Mad, Mad World was, too.

 

No one is saying that smilebox recreates the experience, but it does come closer and it is definitely a different experience than watching a 70mm film.

 

All the setups I've seen online do not show the Cinerama screen anywhere but in front of the audience. The impression that it curves around you has to do with the size and curve of the screen and the fact that you are seeing a panoramic image.

 

Astonishingly, because of the louvred panels, you can project a smilebox formatted film from one projector onto a Cinerama screen accurately, removing the need for three projectors ...and five people running them.

[fae_alba]

This reminded of the "Soarin" attraction at Epcot (and at DisneyLand). There the movie is projected onto what looks like a hemisphere. The seats are on lifts that for the most part move you into the edges of the screen, so you are "inside" the movie. Added to that the motion of the movie is mimicked by the movement of your seat, and the experience is quite memorable.

[Rodney]

Interesting discussion.

 

 

This makes me wonder if A:M's subframe rendering capability could be shoehorned into blending three thinner camera positions into one widescreen image.

 

Does anyone know how Eggslice (Eggprops/Billy Eggington) handled the approach to stitching imagery together? (it seems to me that it accomplished it's feat by leveraging A:M's internal features) The approach to a Cinerama shot might be similar but would extend the process from a camera constrained in XY axis to one that rotates left and right. At a guess I'd say a 'card' placed in front of the camera to block parts of the screen might allow the superimposition of parts of the previously rendered and the anticipated subframes..

[nemyax]

Cropping the bulges off Robert's single "undistorted" image will give you more accurate and flexible results than stitching multiple images together.

[largento]

When I was a kid in the 1970s, we visited Disney World several times and they had a "circle vision 360" attraction. You stood in a circular room with nine screens encircling you and they had hand rails for you to hold on, even though the room itself did not move. I remember they showed "America the Beautiful." It was a flying over the USA movie and I remember holding onto that hand rail because it really seemed like we were flying.

[largento]

This makes me wonder if A:M's subframe rendering capability could be shoehorned into blending three thinner camera positions into one widescreen image.

 

That would be an interesting solution, Rodney.

 

If it were possible, you would end up with a panoramic image, which is desirable.

 

My original question, though, was how to (if possible) set up a Cinerama camera in A:M with the correct camera settings. I'm okay with it having any of the problems that were inherent with Cinerama.

[largento]

They did a lousy job at that but you can't curve the "2001" image onto a Cinerama screen because the camera did not shoot a wide angle of view comparable to what a Cinerama screen presents to a viewer.

 

Here's a link to the guy's math, Robert. You can check it to see the quality of his job. :-)

[fae_alba]

When I was a kid in the 1970s, we visited Disney World several times and they had a "circle vision 360" attraction. You stood in a circular room with nine screens encircling you and they had hand rails for you to hold on, even though the room itself did not move. I remember they showed "America the Beautiful." It was a flying over the USA movie and I remember holding onto that hand rail because it really seemed like we were flying.

 

I remember that one too. I remember standing in the middle of the theater and spinning around trying to catch it all in. The hand rails were there so that numbskulls like me didn't fall lat on their arse during the movie! There was one part of that movie I seem to remember of a battle between Highland Clans. It felt like I was in the middle of the action. So, wouldn't it be interesting to set a chor up to shoot in 360 degrees. Then all you would need to do is build your own theater to show it.

[robcat2075]

Precursor to Cinerama.... the "Hemicycle" of Paul Delaroche. A 180° degree painting on the walls of the Amphithéâtre de l’Ecole des Beaux-Arts depicting great artists of the past, chatting amongst themselves.