week 5 quiz

1. A system takes input “signals” and in return gives output “signals”. For example, an organism’s digestive “system” takes food “input”, and gives ATP (energy) and waste “output”. What is the input and output for a camera system?

Bonus: 1a. What are the measured quantities or ‘units’ for a camera system’s input and output?Example: Digestion system has biomass or molecules of “food input”, and molecules of “ATP output”.Note: This may be redundant if you answered question 1 precisely.

Bonus 2. “Signals” can have “noise”, which is random/informationless variation in the signal. How does noise manifest itself in the output signal of a camera system?Basically: define noise.

3. The amount of apparent “noise” is not measured in absolute quantities, but the ratio of noise to the actual signal, or Signal divided by Noise. This is also known as “Signal to Noise Ratio (SNR)”. For a camera’s light input, the Noise/Signal is sqrt(x)/x, where x is the amount of light, and the graph of sqrt(x)/x is below. Why does higher ISO sensitivity result in more noise?

Week 5 Quiz

0 2000 4000 6000 8000 100000%2%4%6%8%

10%Noise

Amount of light

Blur occurs when you have subject motion – sometimes you want to convey that

Blur can make scenes dynamic like they are in real life

Blur can add a sense of drama to an otherwise ordinary picture

Blur can be used to insert secondary subjects that give context – without drawing attention away from the primary subject

Fireworks at 0.5 seconds Fireworks at 4 seconds

Not all scenes are frozen in a single instant – Sometimes they play out over an extended length of time

Detail can make images “busy” – 1/25s

Long shutter speeds average out the motion, concentrating focus on fewer elements – 10s

In addition to subject motion, you can get creative with camera shake as well

Campanile from Barrows

Campanile from Barrows

Eiffel Tower

Xian Highway lights

Yuyuan Garden, Shanghai

Hearst Mining Stairs

Dialog Box Campanile