The Cyclorama is a cylindrical 360° display. Seven (or fourteen) projectors, driven by Lighttwist, surround the audience with a high definition image or movie – ambiophonic sound included. The following tutorial explains how to output panoramas for the Cyclorama with Hugin. I start with a full spherical panorama, but any Hugin project will do. Make sure the image covers 360° horizontal FoV (field of view) and at least 30° vertical FoV >30°. Images with smaller FoV will leave part of the screen blank.
Start Hugin and load the image(s). Since equirectangular images usually don’t have EXIF data, enter the image type and FoV as in the window below:
Visually check the equirectangular in the Fast Preview window:
On the Stitcher tab, enter the following parameters:
- Projection: Cylindrical
- Field of View: horizontal 360°, vertical 38.5°
- Panorama Canvas Size: width 7200, height: 800
- Crop: 0,0,7200,600
The resolution of the Cyclorama is currently 7200 x 600 pixel, equivalent to 360°x29.3° in a cylindrical projection centered around the horizon. However we do not center around the horizon: the screen will be slightly higher to avoid shadows from the audience inside the Cyclorama. Set the horizon at 1/3 (or 200 pixels) from the bottom (although the human eye is very forgiving). To do so we output slightly more vertical FoV and crop it. Test the result in the Fast Preview window:
The white line is the crop line. When you’re happy with the result, stitch!
As a last step, log on to Ultra Wide Views, select the Cyclorama 2009 exhibition on the upload form and beam the result over. Thank you! It may be shown on the Cyclorama during LGM. The exhibition’s theme will be Horizons. The panorama used for this tutorial is the Mediterranean Sea seen from the coast of Israel in Cesarea. On the beach are the remnants of a two thousands years old Roman aqueduct.
- Make sure your input image has enough resolution for an output at 7200 pixels horizontally. Full spherical panoramas in the range above 6000 pixels are OK.
- Hugin does not apply interpolation filters (yet). Ideally you either first resize the panorama to 7200 horizontal pixels and then run it through the above process, or you output at recommended resolution and resize it later. To do so, set the appropriate FoV values, then click on Calculate Optimal Size. Stitch. Open the result in your preferred image editor, resize and crop. Double-check that the resulting cropped image is 7200×600. Warning: some image editors do not resize well the 360° seam.
- Not all content is appropriate for cylindrical projections. The crop lines at +20°/-10° vertically often cut away important detail. Choose a panorama that fits the medium.