Flashcards in Lecture 5 Deck (52)
What is exposure for still photography and cinema?
recording images of subjects to photo (light) sensitive film or digital media via photo sensor through controlled exposure of the subjects to ambient or / and additional light.
What five main factors control and affect exposure in cinema?
List the available light sources to consider when setting exposure?
Candlelight and flame
What is available ambiance light?
Natural or synthetic light present in the scene location
Name two sources of natural light.
Explain the additional light source film lighting?
Film lighting -mains/battery powered lighting on stands/clamps
Explain the additional light source ‘practicals’
Lights in normal domestic/ commercial light fitting on ceilings/walls/table lamps etc
What are mixed light sources?
Ambient synthetic light
Additional film lighting
5,000 / 6,000 = daylight
As it goes down it gets warmer and as it goes up colder.
Measured in kelvin
Note that the colour of the day with impact the ambient light
What is the colour temperature of candle light?
1,850 -1,930 k
What is the colour temperature of electronic flash?
What is the colour temperature of blue sky, sunlight?
What is the colour temperature of early morning/evening?
What is the colour temp of sunrise/sunset?
Colour temperature of mid morning/afternoon?
Colour temperature of late morning/early afternoon?
Colour temperature of average noon?
5,300 - 5,500 k
Shade or cloud colour temperature is ...?
Anything between 6,000 - 8,000k depending on the clarity of the day
How do you set the white balance on a black magic camera?
Set from choosing from a list of kelvin settings such as 5600k
What is alternative method to establish a white balance?
In many video cameras it involves the use of a push-button control, along its white card/paper places between the main light source and the subject.
How can you manipulate manual white balance settings?
Deliberately creating a warmer (yellow/orange) or colder (blue) than reality can be done by using coloured card for the manual white balance set.
Blue card - warmer as camera tries to neutralise the tint and render it white.
Yellow/ orange - colder as the camera tried to neutralise and render is as white.
Shutter in terms of exposure for cinema
Is expressed in speed (normally approximately 50th second) or angle (normally 180•)
• = degrees
Why is recording moving images using shutter speed limited? List two reasons:
1. Restricted by the need to acquire a number of frames per second to produce ‘moving’ images. E.g 24/25 frames for cinema for tv
You can’t have a shutter below 30th second to get 24/25 frames per second.
2. Faster shutter speeds (over 2 x the frame rate/ f.p.s affect the impression of natural motion.
If light is reduced there will be A reduced amount of motion blur making it seem unrealistic.
What is the frame rate for natural movement?
24fps or 25fps
What is the rule to abide by when choosing shutter speed and keeping motion blur?
Choose a shutter speed twice the frame rate
So 25 FPS needs 50th second shutter speed = 180• shutter angle.
What is the effect of Setting a faster shutter speed or shutter angle?
The images sharper but the motion appears less smooth due to the lack of motion blur.
50th or 60th second are not normally used but can be interesting
At 180• shutter angle what is the shutter speed for 24 FPS
24 FPS is 1/48 sec
25 FPS is 1/50
At 90• for 24 FPS
24 FPS 1/96 sec
25 FPS 1/100
45• for 24 FPS
24 FPS 1/192 sec
25 FPS 1/200