Electromagnetic Spectrum	Visiable light
The Electromagnetic Spectrum	Visible Light

“Capturing” the light…
Light is essential to all photography (except infrared)
Light travels through the lens and onto a light sensitive surface where it is “captured”.

Film Cameras…
• Film has layers:
• • Base (celluloid)
• • Emulsion (silver halide crystals suspended in gelatin)
• • • Red dye
• • • Green dye
• • • Blue dye
• Crystal size determines film speed
• Crystals “clump” when exposed to light
• Unexposed crystals removed during developing

Digital Cameras…
• Light sensors
• • CCD – Charged Coupled Device
• • CMOS – Complementary Metal Oxide Semiconductor
• • Foveon X3 – 3 layered sensor
• Digital = 1 or 0 (binary - “on” or “off”)
• Processor in the camera “organizes” the data and places it on the storage device

CCD_sensor_diagram	CCD
cmos	CMOS
FOVEON_X3_BREAKOUT_1_L	Foveon

Advantages of Digital…
• No film
• No processing time
• No processing cost
• Immediate access to the image (can see the image immediately)
• Shoot under a variety of light without changing film or using filters
• Direct input to your computer (no scanning required)
• Not dependant upon a processing lab

Disadvantages of Digital…
• Possible lower “resolution” not giving the quality achieved with film.
• Battery and storage media dependant
• More expensive than a comparable film camera
• Noise may be introduced into the image
• Can’t use specialized films
• Computer dependant

Neither film nor digital is “better”…they are just different.