Sunday, February 9, 2014

A/V Definitions & Explainations


Lumens : - The measure of brightness of the projector. This is important when you are using the projector in a lit room (lights on or many windows) 2000 is the average. Anything higher would perform better in a lit room, anything lower requires a darkened room BUT will likely have a better contrast ratio. Higher not always better.

Contrast Ratio : - The difference between white and black. Unfortunately not all manufacturers use the same measurements (ANSI vs Full on/off) so this spec can be very misleading and I am NOT going to list any here. Projectors with lower lumens usually have better blacks/contrast until you climb the price ladder. Higher is always better when the same standards are used.

3D : - Well 3D means it can be used with 3D glasses to reproduce 3D content from movies but this also means it must support a 120Hz refresh rate. So gaming will be amazing on it. I personally don't give a rats about 3D.

DLP : - Digital Light Processing- *Essentially a million microscopic moving mirrors bounce white light through a quickly spinning color wheel to make the picture. Believe it or not this is the cheapest method and usually have very good black levels but this system can make a "rainbow effect" occur if the color-wheel is even slightly out of sync or during high motion scenes.

3LCD : - Three Liquid Crystal Display- *The LCD technology we all know and love, times three and squeezed down to about an inch across with light shined through a red, green and blue LCD that gets combined in a prism and delivered to your screen. This method can have better contrast and higher brightness then DLP but costs a premium. Instead of the rainbow effect 3xlcd's can suffer from a microscopic mis-alignment of the panels causing convergence issues but is far less noticeable at normal distances then the rainbow.

D-ILA/SXRD : - These are proprietary forms of image generation based on other methods but implemented more exotically. Want details? Me too.

Laser / LED : - This is a new tech that uses either an LED or a Laser and LED to generate the light instead of a bulb. After that it is pretty much still one of the above systems.

3DLP : - Combines the DLP chips and 3LCD lens system and has three times the micro-mirror arrays so it no longer suffers from the rainbow effect but now inherits convergence issues and a gargantuan price bump. This is the best system.

720p : - Due to the lower resolution of a 720P display the pixels themselves are larger and therefore carry more light out of the projector. This means almost all lower resolution projectors are brighter then their FullHD counterparts and usually 40% cheaper. At certain placements it makes perfect sense to seek out a lower definition projector that can overcome brighter environments.

1080p : - The current gold standard FullHD resolution (ie what bluray's use). It is what you want so make sure any projector you look at states the NATIVE resolution is 1920x1080 and not the MAXIMUM.. Getting those two confused will leave you will a low def projector that can simply accept and resize down your beautiful 1080p signal.

XGA and WXGA : - These are PC aspects that are commonly found on business projectors. 1024x768 and 1280x800 are not really HDTV resolutions (HDTV is 1280x720) Be weary of anything labeled as a "business projector" as it will usually have high brightness but poor contrast and color and be very lightweight.

Keystone Correction : - Can be found digitally or physically. Digital keystone is usually only used in a temporary presentation situation it can be used to distort the image to fix "square" due to the improper placement of a projector. Digital keystone is NOT used on a home theater projector as it destroys image quality by not using the native resolution for each 1 pixel. Physical or Lens keystone can be used as it twists the light emitting from the lens and leaves the resolution intact. 99% of the time meticulous placement of the screen and projector is all that is needed to create a square, flat, correct image.

Lens-Shift : - Usually found on higher-end projectors but creeping down to the entry level is this ability to place the projector almost anywhere behind the viewer and *Shift* the image without using a Keystone up, down left or right to an extent. This can make life MUCH easier then trying to move the physical projector to align with the screen knowing you have to avoid digital keystone correction.

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