Mock-Up Lighting Study for Jakarta Cathedral Church - Sacred Architectural Lighting
Lighting within sacred architecture is not merely about visibility. It is about shaping spiritual atmosphere, emotional perception, and the relationship between human experience and sacred space.
With great enthusiasm in welcoming the Apostolic Visit of Pope Francis to Jakarta Cathedral in September 2024, Herwin Gunawan and ALTA Integra Lighting Design team contributed to enhancing the interior lighting quality of the historic cathedral through a series of architectural lighting mock-up studies.
Measure Color Rendering Index, Flicker and Lux Level at Altar Table
The mock-up lighting study was developed to explore how different lighting strategies can influence visual hierarchy, contemplative ambience, architectural depth, and the perception of religious art and liturgical elements within the cathedral interior.
Rather than focusing solely on brightness, the study investigated how controlled contrast, color rendering quality, luminance balance, and focal illumination could create a more human-centered and spiritually immersive worship environment.
Measure Color Rendering Index, Flicker and Lux Level Congregation Pew
Through a series of lighting mock-ups and visual evaluations, the project examined how light can respectfully reveal the architectural richness, sacred symbolism, and emotional atmosphere of one of Indonesia’s most important religious heritage buildings.
Altar Lighting Strategy
The comparison between the existing altar lighting and the mock-up lighting demonstrates how lighting strategy fundamentally influences the perception of sacred architecture, emotional atmosphere, and spiritual focus within the church interior.
Although both scenes illuminate the same altar, the difference in luminance balance, visual hierarchy, and ambient control produces entirely different spatial and emotional experiences.
Existing Altar Lighting
Bright but Visually Flat
In the existing lighting condition, the church interior appears generally bright due to high ambient illumination distributed relatively evenly throughout the sanctuary.
While the increased brightness improves overall visibility, the lighting lacks:
Strong visual hierarchy
Spatial depth
Focal emphasis
Emotional layering
Architectural contrast
As a result, the altar competes visually with the surrounding walls, floor, banners, and architectural surfaces instead of emerging as the primary sacred focal point.
The lighting perception feels:
Visually flat
Overly uniform
Spatially shallow
Visually noisy
Less contemplative
Less emotionally immersive
Although the space appears brightly illuminated, the lighting lacks visual hierarchy and spatial depth. The excessive brightness creates a visually noisy environment that diminishes the sense of serenity, contemplation, and sacred atmosphere within the church interior.
Mock Up Altar Lighting
Layered Hierarchy and Sacred Atmosphere
The mock-up lighting adopts a more intentional and human-centered lighting strategy by reducing unnecessary ambient brightness and strengthening focal illumination around the altar composition.
Rather than uniformly illuminating the entire sanctuary, the lighting carefully guides visual attention toward the liturgical center through:
Controlled luminance hierarchy
Reduced ambient spill
Focused altar illumination
Balanced shadow retention
Improved contrast layering
This approach allows the altar to visually emerge from the surrounding architecture, creating stronger depth perception and a more contemplative sacred atmosphere.
The lighting perception now feels:
Warmer and calmer
More intimate
More spiritually engaging
Richer in spatial depth
More visually organized
More emotionally immersive
The mock up lighting creates a warmer and more contemplative atmosphere with improved visual depth and hierarchy. By reducing excessive ambient brightness and emphasizing focal illumination around the altar, the space feels calmer, more intimate, and spiritually engaging.
Tabernacle Lighting Strategy
The comparison between the two lighting approaches demonstrates how lighting strategy significantly influences the visual perception, emotional atmosphere, and spiritual experience of the church tabernacle. Although both scenes illuminate the same sacred architectural object, the difference in lighting composition creates entirely different spatial qualities and emotional responses.
Existing Lighting - small spotlight create glare spot and exesive dart spot
Existing Tabernacle Lighting Strategy
Multiple Small Spotlights with Fragmented Illumination
The existing tabernacle is illuminated using multiple small spotlight sources with narrow beam distributions. While this strategy increases localized brightness, it also creates:
Excessive glare points
Fragmented illumination
Harsh contrast transitions
Visual clutter
Uneven brightness distribution
Competing focal points
The multiple bright hotspots generate a visually busy environment where the eye continuously shifts between isolated illuminated areas rather than perceiving the altar composition as a unified sacred focal point.
The lighting perception feels:
Overly contrasty
Fragmented
Visually noisy
Less calm
Less spiritually immersive
The narrow beam spotlights also create excessive dark pockets between illuminated surfaces, causing the sculptural narratives and architectural carvings to appear disconnected from one another. Although dramatic, the lighting lacks overall compositional harmony and reduces the contemplative quality expected within sacred architecture.
Mock Up Testing - Reveal Golden Color and Visual Hierarchy
Mock Up Tabernacle Lighting
Layered and Hierarchical Illumination
The mock up lighting strategy shifts toward a more integrated and layered composition with improved visual hierarchy and controlled luminance balance. The mock-up lighting creates a more refined and cohesive sacred atmosphere by revealing the natural golden warmth and material richness of the historic altar architecture.
This strategy creates:
Stronger visual hierarchy
Better luminance balance
Reduced glare perception
Improved spatial continuity
Greater visual depth
Enhanced sacred atmosphere
Reveal the golden color paint
The crucifix becomes the primary spiritual focal point, while the surrounding relief sculptures and ornamental carvings remain visually connected without competing excessively for attention.
The lighting perception now feels:
More sacred and contemplative
More visually organized
Richer in depth and texture
More emotionally immersive
Calmer and more reverent
Rather than fragmented the tabernacle composition, the lighting now creates layered depth and gentle contrast that guide the eye naturally through the altar narrative. The result is a lighting environment that feels more harmonious, contemplative, and emotionally immersive while maintaining appropriate visual focus and reverence within the sacred space.
Subject & Background Contrast
The lighting study explores how subject-to-background illumination ratio influences visual perception, emotional atmosphere, and spatial hierarchy within a sacred architectural environment.
Rather than relying solely on overall brightness, the design approach evaluates how controlled contrast between the subject and background can shape focus, depth perception, and human emotional response.
Subject - Background Illumination Ratio - Medium Contrast
Subject - Background Medium Contrast Ratio
Balanced Visibility and Spatial Integration
In Medium Contrast Ratio Lighting, the lighting composition applies a medium subject-to-background contrast ratio, where both the subject and altar background remain visibly connected within the visual field.
This approach creates:
Softer visual transition
Balanced spatial perception
Comfortable facial visibility
Natural skin tone rendering
Greater contextual awareness of the architectural background
The medium contrast ratio allows the speaker to remain visually dominant while maintaining the sacred altar as an important spatial backdrop.
The lighting perception feels:
Warm and approachable
Spatially balanced
Calm and conversational
Architecturally integrated
This lighting condition is suitable for:
Religious talks
Community interaction
Hybrid worship streaming
Educational or pastoral communication
Situations requiring both subject clarity and environmental context
Subject - Background Illumination Ratio - High Contrast
High Contrast Ratio
Stronger Focus and Dramatic Emphasis
In the high contrast lighting, the lighting composition applies a higher subject-to-background contrast ratio by reducing background illumination and increasing visual separation between the speaker and surrounding architecture.
This strategy creates:
Stronger visual focus on the subject
Greater sense of depth
More dramatic atmosphere
Reduced background distraction
Enhanced subject prominence
The darker background allows the human figure to emerge more clearly from the space, improving visual hierarchy and directing audience attention more intentionally toward the speaker.
The lighting perception feels:
More intimate
More cinematic
More emotionally focused
More visually dramatic
More contemplative
This approach is particularly effective for:
Recorded presentations
Broadcast environments
Sermons and storytelling
Emotional or reflective moments
Camera-focused communication settings
Via Crucis Mural Paint by Theo Molkenboer
The lighting study demonstrates how color rendering quality and illumination level significantly influence the visual perception, emotional atmosphere, and artistic readability of the Via Crucis mural painting by Theo Molkenboer.
Rather than functioning solely as illumination, the lighting becomes a medium for revealing artistic detail, material color richness, and spiritual narrative within the sacred artwork.
Existing Lighting - Low Color Rendering Index - Low Lux Level
Existing Lighting Mural Painting
Low Color Rendering Index — Low Lux Level
The existing lighting condition produces limited visual clarity due to insufficient illumination level and poor color rendering quality.
The mural appears:
Dim and visually compressed
Lacking tonal separation
Low in material richness
Reduced in artistic legibility
Flat in color perception
Visually muted and less emotionally engaging
The low Color Rendering Index (CRI) reduces the ability of the lighting to accurately reveal the original pigments, textures, and chromatic nuances of the artwork.
As a result:
Skin tones appear dull
Warm color layers become muddy
Fine artistic details are lost
Depth and dimensionality are weakened
The mural narrative becomes less visually expressive
The low lux level further diminishes the mural’s visual prominence within the sacred interior, causing the artwork to recede into darkness rather than serving as an important spiritual and artistic focal point.
The overall perception feels:
Dark and visually subdued
Less inviting
Less emotionally immersive
Less connected to the sacred storytelling intention of the artwork
Existing Lighting - Higher Color Rendering Index - Higher Lux Level
Mock Up Lighting Mural Painting
Higher Color Rendering Index — Higher Lux Level
In the lower image, the improved lighting condition significantly enhances the visual and emotional perception of the mural through higher CRI illumination and increased, yet controlled, lux levels.
The lighting now reveals:
Richer color fidelity
Greater tonal separation
Improved material texture
Enhanced artistic detail
Better visual hierarchy
Stronger narrative readability
The higher CRI lighting restores the warmth and complexity of the original mural palette, allowing:
Skin tones to appear more natural
Gold and earth-tone pigments to emerge more vividly
Fine brushwork and texture to become visible
Visual depth and layering to feel more dimensional
The increased illumination level improves visibility while maintaining a warm and contemplative sacred atmosphere.
Rather than appearing flat or faded, the mural now becomes:
More visually alive
More emotionally engaging
More spiritually expressive
More architecturally integrated within the church interior
What is sacred architectural lighting concept?
The mock-up lighting study demonstrates that lighting quality within sacred architecture cannot be measured only by illumination level alone.
Different lighting strategies create fundamentally different perceptions of atmosphere, spirituality, emotional comfort, and architectural experience. Through careful control of luminance hierarchy, color rendering, contrast, and visual focus, lighting becomes more than technical illumination — it becomes an instrument for contemplation, reverence, and human connection.
For historic religious spaces such as Jakarta Cathedral, sensitive lighting design plays an important role in preserving not only architectural heritage, but also the emotional and spiritual qualities experienced by worshippers and visitors.
This study reflects a broader human-centered lighting approach where light is designed not to dominate the space, but to quietly support sacred atmosphere, visual comfort, and meaningful spiritual experience.
Project Information
Project: Jakarta Cathedral Architectural Lighting
Location: Jakarta, Indonesia
Service: Sacred and Heritage Architectural Lighting Design
Scope: Lighting Mock-Up, Visual Evaluation, Lighting Quality Assessment
Consultant: Herwin Gunawan / ALTA Integra
Year: 2024
