CS 39J > Schedule & Notes > Session 5 Detailed Notes |
http://inst.eecs.berkeley.edu/~cs39j/session05.html
18 February 2005
- Lines get more parallel the longer the focal length.
- For flash and other artificial light sources, apply the inverse square law.
- If a scene is too bright, use a neutral density filter. You can also buy graded density filters.
- Wide angle lenses give more drama to perspective.
- A gentle telephoto lens is the best choice for portraits.
- Always ask yourself where you want your viewer to look.
- Three aspects affect depth of field:
- Aperture - The bigger the opening (smaller f-number), the less depth of field.
- Focal length - A long focal length gives narrower depth of field.
- Focus - Focusing on a close object creates a shallow depth of field; focusing on a distant object creates a large depth of field.
Equations to calculate depth of field can be found here.
- Blur occurs when light reaches a point before or after the film. On 35mm, a blur with diameter of 30 microns (0.03mm) is acceptable sharpness.
- HYPERFOCAL DISTANCE (aka: focus at infinity). Do not focus on the farthest point in the picture if you want infinite focus - focus just before it to have a larger depth of field.
CRITIQUES:
- Caitlin:
- Balcony2: more contrast on railing--needs to stand out move so that the telephone pole/building/tree on left is out of the frame why do the lines converge? move back and zoom in to reduce convergence.
- Staircase: the houses on the top of the composition are a distraction.
- Sylvain:
- 3am: the use of flash is obvious from the lighting on the tree--intensity of the brightness dissipates even lighting on girl was well-executed.
- Brush: the focus of the picture is unclear--real estate photo flowers under the bush are washed out the use of a neutral density filter would have decreased the intensity of the light while keeping a lower depth of field.
- CC:
- B13.3: 95% of the picture is out of focus--this is unnecessary move closer to the fork so that the fork takes up more space crop out the unfocused foreground--it's a large, empty space that detracts from the composition not enough contrast between the fork and the ground; shadow is not obvious.
- Buildings in san francisco: good composition--a good balance of forms in the frame crisp outline of building is lost due to the glare--use a lower f-stop.
- Bianca:
- flowers (orange/white/yellow): great colors white flower is a distraction--focus is the orange flower, but the white flower is too big and covers up too much of the orange--steals the spotlight.
- lily pond: professor barsky really liked this one great composition--lily pads lead the eye all around the composition.
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