LCD Projectors and Document Cameras Defined Or everything you wanted to know but didn’t know who to ask...

LCD Projectors and Document Cameras Defined

Or everything you wanted to know but didn’t know who to ask . . .

Projectors- Two main types:

• Digital Light Processing (DLP)

– Reflect light again hundreds of tiny mirrors called digital micro devices (DMD)

– Each mirror represents one pixel

• Liquid Crystal Display (LCD)

– Operates by shining light through transparent red, green and blue LCD cells

– Typically brighter than DLP projectors with the same lumens

Does Size Really Matter?

• Ultralights - used for traveling presentation

– Weigh under 3 lbs.

– Typically 1000 - 2500 lumens

• Room Projectors

– Weigh in at 8 - 25 lbs

– Brighter than ultralights, 2500 - 5000 lumens

• Fixed Projectors

– Most expensive

– Usually in Auditoriums

– Range from 1000 - 10,000 lumens

Resolving the Resolution Issue

• Each projector has its own “native” resolution at which it works best

• For best projection - set the computer and the projector at the same display setting

• the most popular today being the XGA 1024 x 768 sold in the 4:3 aspect ratio

Projector Resolution OptionsResolution Description

SVGA800 x 600

Great for those on a tight budget. They’re good for PowerPoint presentations that include clip art or line drawing, black and white, showing documents, etc. They are not good for presentations that require a lot of detail or video.

XGA*1,024 x 768

Most computers still output in native XGA, so matching an XGA projector to your computer ensures you won't lose any detail. These are good general purpose projectors.

SXGA1,280 x 1,024

SXGA projectors are high resolution, and will be more expensive than XGA. These are targeted for high end personal computer users.

SXGA+1,400 x 1,050

SXGA+ projectors are becoming more popular, and there are several offerings available in both budget and high-end configurations. These are very good for detailed photography and graphics.

UXGA1,600 x 1,200

UXGA is for very high end high resolution workstation applications that require exacting detail. These are expensive projectors that support a broad range of computer equipment.

* The most popular projector resolution

Is what you see what you get?

• 4 Factors Determine Image Quality– Contrast– Color– Brightness– Illumination spread

Contrast and Color

• Difference between white & black

• Most important when projecting video

• Contrast ratio 250:1 minumum - 2000:1 great!

• More colors the better - especially for video

• Should be able to display 16 million colors or more

Brightness and Illumination

• Brightness indicated by ANSI Lumens

• Minimum 2500 Lumens for a classroom

• Illumination spread - is the image the same brightness from top to bottom and side to side

• 85% illumination uniformity or better

Let the Light Shine!

• Projector Lamps come in 3 main types:

– UHP - Ultra High Performance

– UHE - Ultra High Efficiency - most common

– Metal Halide

• Lamp life - 1000 - 4000 hours

• Lamp Cost - $300 - $600

– Include an extra lamp in the cost of the projector

Conveniences (Extras)

• Wireless Projector• Networked connections - remotely

controlled• Component video inputs for higher

quality video• Digital Keystone correction• Wireless mouse control• Dual computer input

Document Cameras

• Resolution– Two categories - low resolution output (composite

and/or S-video) and those with high-resolution output (1024x768 or higher).

• Refresh Rate– 20 to 30 Frames per second

• Zoom Lens

• Features

• Size

Common Features

• Zoom 4 to 16x zoom• Pan• Auto Focus• Capture images - single or timed continuous• Playback images - view saved images• Freeze image - irregular shaped object• Brightness• Remote control

Bells and Whistles

• Effects - change from color to black and white or negative

• Timer - time the image on the screen - countdown

• Reverse Image• Mirror Image• Night view - lower the frame rate• Download captured images• Optional microscope connections• Optional Interactive whiteboard connections

More Bells and Whistles

• Split Screen view - view both live and captured image

• Picture in picture - view thumbnail of a saved image with the “live” image in the background

• Presenter view - shaded exterior with clear view inside area

Why Should I Use One?

• How can they be used?– Case Studies– Using Document Cameras in the Elementa

ry Classroom– Document Cameras in the classroom– More Classroom Uses– More Case Studies

Web Resources

• 6 Things You Need to Know about Document Cameras

• LCD Projector Guide