2nd/10_Wiki/Topics/AI_and_ML/Lighting and Composition.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-lighting-and-composition	Lighting and Composition	10_Wiki/Topics	verified	self	Lighting Composition Photography Lighting Three-Point Lighting	none	A	0.9	applied	photography 3d ai-image lighting composition art		2026-05-10	pending	language framework prompt midjourney/stable-diffusion/blender

Lighting and Composition

매 한 줄

"매 좋은 이미지는 광원과 frame이 결정한다 — subject가 아니라". 사진/3D/AI image generation 모두에서 lighting (방향·강도·색)과 composition (frame 안의 시선 유도)이 quality를 좌우한다. AI 시대에는 prompt에 이 어휘를 넣어야 결과가 달라진다.

매 핵심

매 Lighting 3원칙 (Three-point)

• Key light: 주광원, 가장 강함, subject 한쪽에서 45도.
• Fill light: 그림자 부드럽게 — key 반대편, 1/2~1/4 강도.
• Back/Rim light: subject 뒤에서 — 윤곽선 분리, 깊이감.

매 Lighting 종류

• Soft light: 큰 광원, 부드러운 그림자 (구름 낀 날, softbox).
• Hard light: 작은 광원, 선명한 그림자 (정오 햇빛, bare bulb).
• Golden hour: 일출·일몰, 따뜻한 색온도 (3000K).
• Blue hour: 일몰 후 30분, 차가운 톤.
• Rembrandt: 코 옆 삼각형 highlight — 영화적.
• Split: 얼굴 절반만 — 드라마틱.

매 Composition 법칙

• Rule of thirds: 화면 9분할, 교차점에 subject.
• Leading lines: 길/난간/시선이 subject로 향함.
• Symmetry: 좌우/상하 대칭 — 안정.
• Negative space: 빈 공간 — minimalism, 호흡.
• Framing: 창문/문/나뭇가지로 subject 둘러싸기.
• Golden ratio (1.618): 황금나선 spiral 따라 배치.
• Foreground / midground / background: 깊이 3단.

매 응용

1. 인물 사진 → Rembrandt + rule of thirds.
2. 풍경 → leading lines + foreground anchor.
3. 제품 → soft key + reflector fill (그림자 제거).
4. 영화 → motivated lighting (창·램프 등 화면 내 광원).
5. AI image → prompt에 lighting term 명시.

💻 패턴

Midjourney prompt — cinematic portrait

portrait of a samurai, rembrandt lighting, side key light from left,
shallow depth of field, 85mm lens, rule of thirds composition,
shadow on right side of face, --ar 4:5 --style raw

Stable Diffusion (SDXL) — 풍경

mountain valley at golden hour, leading lines from river to peak,
foreground wildflowers, low angle, warm tones (3000K),
volumetric god rays, rim light on ridge, ultra detailed
Negative: flat lighting, noon, harsh shadow, centered, no depth

Blender Python — 3-point setup

import bpy
def add_light(name, loc, energy, color=(1,1,1,1)):
    bpy.ops.object.light_add(type='AREA', location=loc)
    light = bpy.context.object
    light.name = name
    light.data.energy = energy
    light.data.color = color[:3]

# Key (45도, 강함)
add_light("Key", (4, -4, 5), 1000)
# Fill (반대편, 1/3)
add_light("Fill", (-3, -3, 3), 300)
# Rim (뒤쪽, 차가운 톤)
add_light("Rim", (0, 4, 4), 800, (0.7, 0.85, 1, 1))

Three.js — 시네마틱 lighting

import * as THREE from 'three';
const scene = new THREE.Scene();

const key = new THREE.DirectionalLight(0xfff0d0, 2.5);
key.position.set(5, 8, 5);
key.castShadow = true;
scene.add(key);

const fill = new THREE.DirectionalLight(0xa0c0ff, 0.6);
fill.position.set(-5, 3, 3);
scene.add(fill);

const rim = new THREE.SpotLight(0xffffff, 4, 30, Math.PI/8, 0.5);
rim.position.set(0, 5, -8);
scene.add(rim);

scene.add(new THREE.AmbientLight(0x404040, 0.3));

CSS — rule of thirds grid overlay (디자인 검증)

.thirds-overlay {
  position: relative;
}
.thirds-overlay::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, transparent 33.33%, rgba(255,0,0,.4) 33.33% 33.5%, transparent 33.5% 66.66%, rgba(255,0,0,.4) 66.66% 66.83%, transparent 66.83%),
    linear-gradient(to bottom, transparent 33.33%, rgba(255,0,0,.4) 33.33% 33.5%, transparent 33.5% 66.66%, rgba(255,0,0,.4) 66.66% 66.83%, transparent 66.83%);
  pointer-events: none;
}

Lightroom-style — exposure 검증 Python

import numpy as np
from PIL import Image

img = np.asarray(Image.open("photo.jpg").convert("L"))
# zone system: 0-255 → 11 zones
hist, _ = np.histogram(img, bins=11, range=(0, 256))
print("Shadow %:", hist[:3].sum() / img.size * 100)
print("Mid %:", hist[3:8].sum() / img.size * 100)
print("Highlight %:", hist[8:].sum() / img.size * 100)
# 일반: 20/60/20 근처가 균형

매 결정 기준

상황	Approach
인물, 부드럽게	soft key + fill, golden hour
인물, 드라마	hard key, Rembrandt/split, no fill
제품	softbox key + reflector fill + rim
풍경	golden/blue hour + leading lines
AI prompt	lighting term + 광원 방향 + 색온도

기본값: 3-point lighting + rule of thirds + foreground anchor.

🔗 Graph

• 부모: Cinematography
• Adjacent: Post-Processing

🤖 LLM 활용

언제: prompt에 lighting/composition vocabulary 추가, 이미지 분석해 lighting 약점 지적, 영화 reference 매칭. 언제 X: 실제 촬영 장비 selection — 물리적 spec은 manual 확인.

❌ 안티패턴

• Flat lighting: key=fill — depth 없음.
• Centered subject 항상: 정적, 시선 고정 안 됨.
• 너무 많은 광원: 그림자 충돌, 비현실적.
• Negative space 0: 답답함.
• Lighting term 없는 AI prompt: 평범한 결과.

🧪 검증 / 중복

• Verified (cinematography textbooks, Adobe Lightroom 2026).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — Blender/Three.js 코드, AI prompt 추가