1. 1 Digital Cameras Consumer digital cameras have been around since 1995 What features make a good camera? How do we optimize good features with a limited budget?

2. 1 Exposure How many photons contribute to each pixel? – More is better! Exposure is a combination of several factors – Aperature Size – Shutter speed – Lens size – Sensor Sensitivity – Sensor size (bigger is generally better)

3. 1 Lens The lens gathers light The lens focuses the image Sharpess of the image depends on the lens Larger lenses gather more light Smaller lenses allow for a smaller camera

4. 1 Lens Focal Length Focal length – Macro have short focal lengths Allow imaging small objects – Normal have intermediate focal lengths Most cameras have one – Telephoto have large focal lengths Allow imaging far away objects

5. 1 Field of View

6. 1 Vignetting A gradual fading of the image away from the center Caused by lens optics

7. 1 Optical Zoom Changes lens focal length More lenses can lead to glare and loss of sharpness Large zoom can benefit from image stabilization

8. 1 Digital Zoom Digital zoom extracts a region Similar to cropping Use optical zoom if possible

9. 1 Shutter Speed Controls how long the sensor is exposed Short – Need lots of light – Good for moving objects Long – Good for stationary objects – Need less light

10. 1 Aperture Controls amount of light entering camera Provides field of view – Small aperture acts like a pinhole Entire image in focus – Large aperture Narrow range in focus Provides emphasis on foreground objects

11. 1 Viewfinder Allows us to identify the content of the image Optical – Through the lens – Off axis Electronic – Small – Full-size

12. 1 Camera Display Small Screen Review of images Camera control Viewfinder

13. 1 Sensor Acquires the image Electronic equivalent of film CCD – Charge-coupled device CMOS – Complementary Metal Oxide Semiconductor http://www.shortcourses.com/how/sensors/ccdwaffer.jpg

14. 1 CCD vs. CMOS

15. 1 Mosaic vs. Foveon

16. 1 Analog to Digital Conversion Electronic cameras convert energy from an analog signal to digital – Discrete in time – Discrete in amplitude

17. 1 Quantum Noise Based on the number of photons Variation is the square root of the number of photons http://telin.rug.ac.be/~frooms/research/steer/www/

18. 1 Other Noise Electronic – Heat – Cheap Electronics – Design Senosor – Bad pixels Hot Cold – Bad line See http://www.imatest.com/docs/tour_lightfall.html http://www.starizona.com/ccd/software/biasframe.jpg

19. 1 Camera Speed Time to read sensor Time to write image to media Faster is better

20. 1 Compression JPEG JPEG2 Is the image always compressed?

21. 1 Data Storage Media Physical device where images are stored Tradeoffs – Physical size (smaller is better) – Speed (faster is better) – Data size (larger is better) – Cost per GB (more is better) – Reliability How permanent is the storage? What is the failure rate? – Availability What other devices can use the media?

22. 1 Noise Statisitcal variations in the pixel values Noise obscures detail

23. 1 Battery Power Provides camera with power Disposable – Costly in long run – Low power Rechargeable – Lithium – NiMH Important question – How many pictures can be taken on one charge?

24. 1 Camera Settings What special features does the camera provide? – Shutter priority – Aperture priority – Movies – Red-eye reduction – Delayed shutter

25. 1 Connectivity How does the camera interface with computers? – USB – Firewire – Serial – Removable media

26. 1 Flash Does camera use a flash? – Internal – External

27. 1 Tripod Holds camera Useful for – long exposures – Repeated shots

28. 1 Carrying Case Holds camera and other supplies – Tripod – Batteries – Recharger – Manual – Extra media

29. 1 Hybrid Cameras Digital camera that can directly print to polaroid film any desired photos Preview of film images before processing Dual film/digital camera where one can easily switch between the two modes A 35 mm cassette that has the same form factor as a film camera, yet acquires digital images Direct digital conversion of film during processing