Screen Shape and Size
The key is to begin with the user experience and work your way to an appropriate display technology. First, decide what kind of environment is needed. Here is a quick overview of basic screen shapes and their advantages.
The number of simultaneous users determines the size of the screen (specified here in meters). Keep in mind that if the screen diameter doubles, the square footage available for the audience increases by a factor of 4. For example, a 6 m Theater can comfortably hold 25 people, while a 12 m Theater can hold 100 people.
- Theater, a fully enclosed environment with imagery above, slightly below and all around the audience
- Portal, a forward-facing partial dome designed for casual immersion, offering a natural field of view for a standing person.
- Pano, a sweeping wrap-around screen for enhanced horizon displays like geospatial visualization and flight simulators
- Fulldome, a typical planetarium-style screen with all imagery above the user's head.
The Elumenati offer resolution options of 1400x1050, 1920x1200 and 2560x1600 pixels. The superior image quality provided by even the entry-level resolution option means that it is now the quality of the content that determines the user experience. Our two most popular system resolutions are detailed below:
- 200 Series 1920x1200: The LOCS display panels of the 200 Series provide the highest fill-factor in the industry. They also are 3-channel systems which provide the best color saturation.
- 500 Series 2560x1600: This single DLP projection system exceeds the US FAA specification for the highest level flight simulators (Level C and D simulators require 5 arcmins/pixel or better).
Real World Specifications
Resolution is the most frequently over-specified characteristic of any immersive environment. Take some time to read the attached white-paper on Real World Specifications, and build the most effective solution.
Digital Dome Theaters: Real World Specifications (236kb PDF)
Why Truncated Projection?
Fulldome projection fills an entire hemisphere with imagery, as in traditional planetarium projection. Truncated projection fills slightly less than the entire hemisphere, similar to the original IMX theaters, but concentrates imagery in one area. While OmniFocus systems can deliver either fulldome or truncated projection, we prefer to use truncated projection whenever possible. Here's why.
Refer to the image above for this discussion. Fulldome projection from a single projector solution means that the projected pixels are limited to a fully inscribed circle on the display panel. This means that only 50% of the available pixels are used, and the resolution is limited to the vertical resolution of the projector. Truncated projection optimizes the use of a single projector by inscribing the projected circle along the horizontal of the display panel. Truncated projection typically uses over 80% of the available pixels. Modern immersive environments typically use theatrical seating, with the audience all facing forward, so fulldome projection would place images behind the audience’s heads. Truncated projection places images in the audience’s natural field of view and increases both brightness and resolution by roughly 60% over fulldome projection.
The following are some examples of immersive environments using both fulldome and truncated projection. The first shows various 200 series projector placements in a fixed dome (a planetarium with an opto-mechanical projector in place). The orange section of the dome represents the extent of the projected image. Notice that in all cases using truncated projection that the “shadow region” where there is no image on the dome is always behind the user and essentially ignored.
Below is an illustration of the GeoDome Theater using truncated projection. This configuration offers distinct advantages beyond resolution and brightness. Again, the orange on the screen represents the extent of the projected image. Notice that users near the projector are not only fully immersed horizontally (the image extends beyond their FOV); they also experience image below the horizon. This downward FOV is critical to create a sense of place. For example, landing on the planet Mars is far more believable with the ground is below you rather than 8 feet in the air! The perspective image shows the extent of the projected rays and defines where the audience can be located without casting shadows on the screen.
Content & Budget
As always, your choices around content are dictated by the user experience you want to create. Will your content be interactive or pre-rendered? Will a docent give presentations, or will the user drive her own experience? Will the user interface be a touchscreen, a tablet, a game controller? When creating custom content for immersive environments, the rule of thumb is that clients should budget the same amount for content as they spend on hardware. Elumenati software solutions are designed to help you to maximize your investment.
- Unity3D is the most effective and least expensive way to create custom interactive content. Our Omnity plugin makes it simple to port that content into domes of any shape or size.
- WorldViewer lets you create interactive stories for your GeoDome using existing media from a range of sources: Science on a Sphere animations from NOAA, geolocated images, and video created for both domes and flat screens. Educators can quickly incorporate science stories as they happen in the news, and it's easy to keep your content evergreen.
- The Fulldome plugin for Adobe AfterEffects and DomeView Pro are tools that let you configure content for various resolutions and screen shapes – whether you’re converting a fulldome master or you’ve captured new footage with a wide-angle lens.