# item.guide
Side-by-Side Comparison Exposure & Optics

Color Temperature & White Balance vs. Cinema Shutter Angle & 180° Rule

Comparing 2 standards across 13 specifications. 13 key differences identified.

Comparing:
Color Temperature & White Balance
Cinema Shutter Angle & 180° Rule

Color Temperature (measured in Kelvin / K, standardized under CIE illuminant standards) defines the spectral chromaticity of light emitted by an idealized black-body radiator. Governing camera white balance, it ranges from warm Candlelight (1800K) and Tungsten Studio (3200K) through Photographic Daylight (5600K / CIE D55) to Overcast Sky (6500K / CIE D65) and Deep Blue Shade (8000K–10000K).

View full Color Temperature & White Balance spec sheet →

Shutter Angle (measured in degrees from 0° to 360°, originating from circular rotary disc shutters in 35mm motion picture cameras) is the cinematic standard for measuring exposure time relative to frame rate (Shutter Speed = Frame Rate × 360° / Shutter Angle). The universal '180-Degree Shutter Rule' (exposure time = 1 / (2 × Frame Rate)) delivers natural, organic motion blur that mimics human eye persistence.

View full Cinema Shutter Angle & 180° Rule spec sheet →

Specification Comparison Table

13 Parameters
Parameter / Spec
Tungsten / Halogen Standard
3200 K (Standard interior film incandescent / studio tungsten quartz lighting)
Commercial Warm White Home Lighting
2700 K to 3000 K (Warm ambient household LEDs and Edison bulbs)
Direct Sunlight / Flash Standard
5500 K to 5600 K (Standard photographic electronic flash and noon direct sunlight)
CIE Standard Illuminant D65
6504 K (Standard average daylight definition, sRGB / Rec.709 / Display P3 monitor white point)
Overcast Sky & Open Shade
6500 K to 8000 K (Cool blue-tinted indirect atmospheric skylight)
Mired Shift Calculation
Mired = 1,000,000 / Kelvin (Used for precise optical color temperature warming/cooling filters)
Tint Tint Scale (Green / Magenta)
Orthogonal CC tint axis (corrects for fluorescent mercury gas spikes and green LED CRI spikes)
Mathematical Formula
Shutter Speed (t) = 1 / (Frame Rate × (360° / Shutter Angle))
180° Standard Shutter Rule
Exposure time is exactly half of the frame duration: at 24 fps = 1/48 sec | at 30 fps = 1/60 sec | at 60 fps = 1/120 sec | at 120 fps = 1/240 sec
90° Narrow Shutter (Action Effect)
Fast exposure (1/96 sec at 24 fps) — crisp, staccato, jittery combat motion (Saving Private Ryan effect)
360° Open Shutter (Dream / Smear)
Full-duration exposure (1/24 sec at 24 fps) — extreme motion blur, dreamy light trails, maximum low-light intake
172.8° Shutter Angle (Flicker Reduction)
Eliminates 50 Hz European AC electrical lighting flicker when shooting at 24 fps in PAL regions
Cinema Camera Standard
ARRI Alexa, RED, Sony FX6/FX9, Canon C300, and Blackmagic display shutter in degrees to maintain constant motion blur during frame rate ramps