IMAX 15/70

History

The IMAX 1.43:1 format has a history independent of other studios:

Founding and Development:

• 1967: IMAX Corporation founded in Canada (by Greg Ellenson, Milo Rankin, Roman Kroitor)
• 1970: First IMAX projection at Expo '70 in Japan ("Fuji Pavilion")
• 1971: "The Incredible Shrinking Man" - first IMAX documentary
• 1977: Construction of the largest IMAX cinema (500+ seats)
• 1983: OMNIMAX (dome format) developed
• 1992: "Tango" - feature film in IMAX (not a Hollywood blockbuster)
• 1997: "Titanic" - scenes re-mastered in IMAX
• 2002: "Apollo 13" - Hollywood film fully re-mastered for IMAX
• 2009: Avatar IMAX 3D - turning point for commercial IMAX blockbusters
• 2010-Present: Marvel/Disney use IMAX for blockbusters

Philosophy:

• IMAX has always been "More than a movie" - an experience
• 15-Perf 70mm standard was a conscious Ultra-HD choice
• Documentary focus (National Geographic, BBC)
• Later: Commercialization for blockbusters

Technical Details

IMAX 1.43:1 Aspect Ratio Specifications:

Film Format:

• Standard: 65mm film stock (also IMAX 70mm with soundtrack)
• Official Name: "15-Perf 65mm" or "15-Perf 70mm"
• Aspect Ratio: 1.43:1 (15 perforations height × 69.7mm width)
• Image Size: 69.7mm × 48.8mm effective image area
• Frame Rate: Typically 24fps, occasionally 30fps

Comparison Table of IMAX Specifications:

Detailed Technical Data:

• Film Stock Speed: 190 cm/s (Faster than standard 35mm)
• Light Output: 18-25 Foot-Lamberts (with 400W Xenon lamp)
• Screen Size: Typically 22m width × 16m height (70ft × 50ft sky-high format)
• Audience Viewing Angle: 60-70 degrees horizontal, up to 55 degrees vertical
• Depth of Field: Extremely shallow (large aperture requires focus precision)

Mirror Projection System:

• IMAX uses a unique mirror system (not standard lens projection)
• Allows for larger projection without lens distortion
• Multiple mirrors direct 65mm film to screen
• Special lamps required

Usage Today

The IMAX 1.43:1 format is still exclusive and rare, but has seen a resurgence through Hollywood blockbusters:

Native IMAX Productions (Shot on 15-Perf 65mm):

• "Mission Impossible: Ghost Protocol" (2011) - Brad Bird
• "Interstellar" (2014) - Christopher Nolan (partially shot in IMAX)
• "Oppenheimer" (2023) - Christopher Nolan (massive IMAX footage)
• "The Dark Knight Rises" (2012) - Christopher Nolan (partially)
• "Ant-Man and the Wasp: Quantumania" (2023) - Marvel/Disney

Commercialized IMAX Versions (Remastered):

• "Avatar" (2009) - Re-mastered for IMAX 3D
• Marvel Blockbusters: Certain scenes optimized for IMAX
• Christopher Nolan Films: Extreme IMAX muxing

Documentary/Educational Use:

• National Geographic: Documentaries in IMAX
• BBC Nature Series: Partially for IMAX theaters
• Planetarium Shows: IMAX as standard
• Museum Installations: Art projects utilize IMAX

Why the Renaissance:

• Christopher Nolan is an IMAX evangelist (has used it extensively since 2012)
• Marvel/Disney recognized the marketing potential
• Streaming competition drives cinemas to seek an "experience"
• IMAX theaters are an investment for studios
• Technological advancements (4K digital IMAX) improved accessibility

The 1.43:1 Format in Artistic Practice

Why 1.43:1 and not 1.85:1 or 2.35:1?

The seemingly "squarer" proportion of 1.43:1 is actually a deliberate choice:

• Monumental Height: People appear smaller against vast environments
• Sky Maximization: Air, clouds, cosmic expanses utilize full height
• Architectural Space: Churches, buildings utilize verticality
• Psychologically: Near-square evokes a different emotional response

Example: "Interstellar"

• Christopher Nolan used IMAX for space scenes
• The black void of space is amplified by the height
• The Cooper family in the farmhouse uses the full depth of the frame

Comparison: IMAX 1.43:1 vs. Other Large Formats

Digital IMAX - The Dichotomy

Modern IMAX cinemas utilize two systems in parallel:

1. Film-Based IMAX (Original):

• 15-Perf 65mm film projection
• 18K resolution equivalent
• Only in larger cities now
• Extremely expensive to produce

2. Digital IMAX (2008+):

• 4K dual-laser projection
• 60% of IMAX cinemas are digital
• Compatible with 16:9 and other formats
• More affordable for studios

Controversy:

• Purist IMAX: Only 1.43:1 70mm is "true" IMAX
• Practical IMAX: 4K digital is more accessible

Interesting Factors for Filmmakers

Why Nolan Obsessively Uses IMAX:

Christopher Nolan has repeatedly stated:

• IMAX cameras force thoughtful filmmaking
• Cost + Size = Responsibility
• Every frame is valuable
• Viewers cannot see a mistake (even in 35mm)
• IMAX is "real" cinematography

The Practical Challenge:

• Few studios own IMAX 65mm cameras
• Panavision dominates the IMAX market
• Shooting costs are 3-5x higher than standard
• Post-production infrastructure is specialized

Future Perspectives

Trends:

• Hybrid: Partially shot in IMAX, partially standard
• Digital IMAX expands, 70mm cinemas close
• Streaming services (Apple, Netflix) invest in IMAX restorations
• Artificial 1.43:1 through cropping 2.35:1 material

Further Information

Technical Standards:

• IMAX Corporation Specifications (proprietary)
• SMPTE RP 486: 65mm Film Standards
• Panavision IMAX System Documentation

Related Entries:

• 15-Perf 65mm (Technical Description)
• 65mm / 70mm (Film Format)
• Cinemascope (For comparison)
• Christopher Nolan (Artist's Perspective)