 |
|||||||
 |
|||||||
 |
T436 - Fall 2012 - Week 4 Readings: Blain Brown, chapters 10, 11, 12 & 13. Watch DVD chapters on lighting and gripology. Agenda/Reality check:
Lighting (continued) Review from chapter 7: Know the difference between upstage verses downstage lighting (similar to narrow vs broad). In upstage lighting the key is upstage of the camera (just like in narrow lighting - the key is on the opposite side from the camera). Practicals - Real life lighting instruments appearing on set. They are best used with a dimmer. According to the fabulous DP Michael Minnock, all objects must do 2 out of 3 things:
Lighting people and spaces (Zone system & pools of light) High key lighting – low contrast lighting used in sitcoms. Feels
light Getting the mood across is a combination of lighting, composition, camera, blocking, and acting. But lighting generally plays a key role in establishing mood. Consider the following questions: How would you make something or someone scary or tense? There are certainly lighting techniques - low key lighting for scary. Low angle. Pools of darkness. One could use high key lighting for lightness. It's a combination of elements. Character, story point, character arc in relation to story line. Music, cutting, framing of shots. Lighting is only one element. Get them all to work together and you have something.
Exposure (chapter 10) ------------------------------------------ Four Elements of Exposure:
For video, it's always better to underexpose a little rather than to overexpose a little. (But try to make it perfect.) f-stops F-stops show a ratio of focal length to diameter
In other words, changing by one whole f-stop changes by a factor of 2 (or 1/2).
An f-stop of 1 is the largest opening one could theoretically have. Focal length review: Focal length = distance from optic center (or principle plane) to target (or corresponding focal plane) f-stop = focal length / diameter of lens Zone System The Zone System provides a good way to plan lighting for a scene. The book has an excellent example on page 204. Here's another (on-line) example: http://f164.com/the-zone-system-for-digital/10/2011/
Lighting & Light Meters Incident vs. Reflected light Incident light is measured from the source. Most light meters have domes used to measure incident light. One would stand where the subject is and aim the meter at the lighting device to measure it. For photographers, reflected light values are usually more useful. These measurements are taken off of the subject. In a light meter's spot metering mode (available on the Sekonic L-558), we are measuring reflected values. Reflected light meters assume they are looking at an 18% gray card. 18% gray card – incident equals the reflected amount.
On using the Sekonic L-558:
Notes on the Sekonic L-558 display:
Sekonic’s light meter faq: Inverse square law The inverse square law applies to sound, gravity, and point source light (energy that radiates). In other words, it doesn’t apply to laser beams. It works best with a bare candle or bulb radiating light evenly in all directions. Point source light's intensity is inversely proportional to the square of the distance Assume a light casts a quantity of 100 footcandles at 10 feet
There's a good explanation of the inverse square law at: Inverse Square Fun with the light meter: You can test the inverse square law yourself using the Sekonic L-558. To do so, use a point source light (E.g. bare bulb) and setup the Sekonic to function in incident mode (page 26 of the manual):
Zone System The Zone System is useful for objectively and accurately designing and analyzing lighting setups. Understanding how to use the zone system is key to lighting scenes. While we can have as many zones as we want in a zone system, let's use 10, as this is a good number to use for video. On a waveform monitor, digital black is 0 IRE. The brightest white is 100 IRE. Pure black is Zone 0
(18% reflectance) On a waveform monitor, this is about 55 IRE
Camera Movement (chapter 11) Be sure you know the various types of camera moves and what they accomplish
Mounting devices: Handheld Types of Camera Heads:
High Hat - Low to gound mount Dollies Cranes Motion Control (Good examples include Michel Gondry's Kylie Minogue video "Come into My World" (with some awesome difference keying and layering) or clips from Amelie) Chapter 12 color Know the two color systems (additive/RGB and subtractive/CMYK) and what they are used for. Know the two basic compensation gels: CTO (color temperature orange) and CTB (color temperature blue) and what they are used for. Chapter 13 image control Filters Can be round, square or rectangular Filter Types
Always think in terms of f-stops and how you are affecting them. GainEvery 3 db of gain is 1/2 of a stop. 6 db of gain is a whole stop. ND filters*
Polarizing filters take of 1.5 to 2 stops CTB gels can take off 75% of a lamp's output. Scrims (the type that slide into a light's filter frame) come in singles and doubles. Singles take off a half a stop, doubles take off a whole stop. ND filters
Polarizing filters take of 1.5 to 2 stops Problem Solving: You are on the beach on an overcast day. You need to shoot some video of someone walking along the shore. You want to use a 100mm lens at f-2 in order to have the proper depth of field and angle of view. However your light meter tells you that you ought to be shooting at f-4. What should you do? Solution: You need to figure out the difference between the actual reading and the desired f-stop. The difference between f-2 and f-4 is 2 f-stops. Therefore if you used an ND filter of .6, it would take off two stops. Misc. Filter info links:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|