Tuesday, March 10, 2015

Everything You Ever Wanted to Know About Projectors


But Were Afraid to Ask

So the big event is tomorrow and you just find out your client neglected to mention they need an LCD projector to display there PowerPoint slide shows. You think, "this should not be that hard." You call a few local AV companies and are bombarded with questions by the AV rep who appears to be talking in tongues; From Lumens, Resolutions, Aspect Ratios to Throw Distance and Front or Rear Projection. Now that this AV guy has you feeling less than intelligent you try not to sound too defensive and say, "just bring me a regular projector." When the "regular" projector arrives and your client arrives also, with his Mac laptop you discover the Mac needs an adapter and the PowerPoint has high definition videos that look horrible through the "regular" projector. If this world is still a bit of a mystery let's venture into the ins and outs of projectors.

Lumens: The Fancy, Glorified Word for Brightness

Note: Movie theaters, while almost completely dark, use between 15,000 and 30,000 Lumen projectors.
One of the most important aspects of a projector is its brightness. The brightness of a projector is determined by the amount of Lumens the projector's lamp produces. Simply put, the higher the amount of Lumens the brighter the projector. Early on In the AV rental business I was taught when buying projectors buy the highest Lumen projectors, or brightest you can afford. In other words, you can always substitute a lower Lumen projector with a higher Lumen projector but not the other way around. On the lower end of the spectrum are projectors rated between 1000-2500 Lumens. In a completely dark room or a room totally absent of light, a 1000 Lumen projector may be sufficient. The issue then becomes the amount of light your projector will have to battle to reproduce the image it is being provided from the laptop, DVD Player, camera, etc. The more light introduced into the space between the projector and the projection screen means the more Lumens required to achieve a satisfactory image on screen. The size of the projection screen is not as important as most would be led to believe until you get into screens 12 feet wide and larger. Mid sized projectors are projectors rated between 3500-5000 Lumens. These are satisfactory for the amount of light within a well lit office conference room or hotel meeting room. In most cases you will be dimming the room lights slightly anyway during the actual presentation. Large event projectors are rated between 7500-10,000 Lumen and are used for bright rooms or rooms with windows where sunlight may enter. Large event projectors are also used for bright rooms with larger projection screens, such as 16 feet wide and larger.

High Definition is in Cahoots with Resolutions and Aspect Ratios

High Definition video is technically any video content recorded at a resolution of 1280 x 720 (WXGA) or higher.

Photo is Standard Definition, Low Resolution 600 x 400

Photo is High Definition 2592 x 1768

Common Resolution Table
Format - - Resolution - - - - Aspect Ratio
SVGA - - - - 800 x 600 - - - - 4:3 (Standard Definition)
XGA - - - - - 1024 x 768 - - - 4:3 (Standard Definition)
WXGA - - - - 1280 x 720 - - - 16:9 (High Definition)
WXGA - - - - 1280 x 800 - - - 16:10 (High Definition)
FHD - - - - - 1920 x 1080 - - - 16:9 (Full High Definition)
WUXGA - - - 1920 x 1200 - - - 16:10 (High Definition)

Room, Space and Throw Distances

In the event industry you almost never have enough space. You start your floor-plan mock-up; drop in your tables, chairs, riser and projection screens but almost never account correctly the space between the projector and screen. This is where short throw projectors and front or rear projection come into play. Front projection is placing the projector in front of the projection screen, with the projector visible to attendees and rear projection is placing the projector, hidden behind the screen. Rear projection gives the most professional and clean look between the two but is not always possible, due to lack of space. For this reason I recommend, when ordering your AV, request a projector with a short throw lens. A lens's throw distance is measured by a throw distance ratio. In this case the lower the number the shorter the throw. Projectors with interchangeable lenses come standard with a lens about 1.65:1 but can accept lenses with a throw ratio as low as .8:1 (varies by zoom and manufacturer).

For example, using a 10ft wide screen, a lens with a 1.65:1 throw ratio will require 16 feet of space between the projector and screen. On the other hand, a projector using a .8:1 lens only needs 8 feet between it and the 10ft wide screen.There are also ultra short throw projectors. While these projectors can achieve a throw ratio of as low as .48:1 they often do not have a zoom feature and do not offer interchangeable lenses.

Tip for Connecting Projectors and Laptops

When connecting a laptop to an LCD projector for an event, movie night or any occasion, for best results and to avoid any failure in communication between the two devices follow these simple rules.
  1. Always power up the projector first.
  2. Connect all cables before powering up the laptop.
  3. Laptop should be off, not sleep.
  4. 90% of the time, as the laptop boots up it will automatically connect to the projector.
  5. When presentation has ended power off the projector but let the internal fan run about 5 minutes before unplugging, to cool the lamp.

If you enjoyed the post, please leave a comment and let me know!

Bruce Johnson
A.V. Rental Services, Inc.
4039 Comly Street
Philadelphia, PA 19135
PH: 800-695-5943
FX: 215-904-8503