====== Light Bulb ======

^ Name               ^ light meter (ISO 100, T 125) ^^^
| ikea 9W 5000K bulb | inner: F5, EV12 | softbox: F1.8, EV9 | 1m: F0.8, EV6.5 |
| set photo 135W 5500K bulb | inner: F6.3, EV12.8 | softbox: F3.2, EV10.7 | 1m: F1.1, EV7.3 |

====== Color Temperature and Lumens ======

  * ref: https://blog.1000bulbs.com/home/color-temperature-explained

Quick Notes:
  * 5000K, like sun light look (cool)
  * 2700k, like flame look (warm)
  * **Warm Color Temperatures** (2700K to 3500K): 
    * people more like these color, often seen in home and hotel or restaurant
  * **Cool Color Temperatures** (4000K to 4500K): 
    * often as task lighting in offices, kitchen under-cabinet lighting or craft rooms
    * human see higher color temperatures to be "brighter" (lumens) than warm temperature
    * human see higher color temperatures to be "clean" (like those product flash shots, flash is 5600K)
    * human see higher color temperatures to be making "Object Color Clear" and "Things to spot clean", like toilet, kitech cleaning check
  * **Full Spectrum Color Temperatures - Daylight = full sepctrum** (5000K to 6500K): often seen in museums, jewelry stores, showcase windows, and hospitals

**Object Color Distort by Color Temperature**
  * color temperature + light brightness + rendering (Color Rendering Index - CRI) can cause human see/precept color "Differently"
  * ref: https://blog.1000bulbs.com/home/what-is-metamerism
  * Fight Between "Camera White Balance setting" and "Light Color Temperature"
====== LED Lights ======

  * E27: means standard Edison screw bulb, 27mm diameter (Thumb size), [also used in cheap softbox lights]
  * E14 (SES): small Edison screw mount, 14mm diameter (pinky size)
  * E17 (IES): intermediate, like for microwave
  * E12 (CES): Candelabra, like for decoration
  * E10 (MES): miniature, like torch buibs

  * Illuminance (照度):
    * Luminous energy per unit time 
    * If you ILLUMINATE an object and measured the amount of light being projected towards it by the light, that is ILLUMINANCE
    * lux (= lumen per square metre) 
  * Luminous flux, luminous power (光通量):
    * Luminous flux incident on a surface 
    * LUMINANCE is the amount of light reflected off the surface being ILLUMINATED!
    * lumens = Luminous flux
  * ref: 
    * [[https://en.wikipedia.org/wiki/Lumen_(unit)|https://en.wikipedia.org/wiki/Lumen_(unit)]]


^ Light       ^ Temperature | accuracy ^ watte | lumens | vari    ^ Modifier ^ Price | Exposure |
| Godox SL60W | 5600k+200K | CRI93     | 60W   | 4500   | 10-100% | Bowens mount | 125sgd | remote | (60cm, direct) EV10.5 (1/60,iso100,f5) \\ (60cm,umbrella) EV9 (1/60,iso100,f2.8) |
| Aputure 120D ii | 5500k  | CRI96     | 180W  | 14300 |          |              | 1000sgd | remote |
| Godox SL200W | 5600k+200K |           | 200W  | 20000 |  | | 500sgd |
| TRADFRI LED E27 980lm | 2.2-2.7,4k | |       | 980    | ~       |              | 40sgd | remote |
| TRADFRI LED E27 1000lm | 2.7k? | | | 1000 | ~ |                                | 30sgd | remote | |
| RYET LED E27 1000lm | 5k |     | 9W    | 1000   |         |              | 3sgd  | | (60cm, diffuse, 3x) EV9 (1/60,iso100,f2.8) |
| LEDARE LED E27 1000lm | 2.7k-warmer | CRI90 | 11W | 1000 | ~ |                   | 5sgd |
| LEDARE LED E27 1000lm | 2.7k-warmer | |     | 1000 | ~  |                  | 8sgd |
| LEDARE LED E27 1600lm | 2.7k-warmer | | 16W | 1600 | ~  |                  | 10sgd |

  * Godox SL60W review
    * https://www.adorama.com/r/gosl60w-reviews
    * https://digital-photography-school.com/godox-sl60w-review/
  * Aputure 120D review:
    * https://digitalfilmmaker.net/led-fresnel-aputure-light-storm-cob-120d/
    * http://www.wetestlights.com/test.php?l=307&n=Light%20Storm%20120d%20II