Projectors

I am not an AV equipment expert by any means, but I recently did some research regarding the best portable projectors.  In order to do the research, I had to understand some basics.  I thought I’d share some of what I learned.  Maybe it will help shed some light for others, like me, new to the market. 

Considerations

There are several points to take into consideration when purchasing a projector. 

1. I suppose the first would be to answer the question, “why are you purchasing a projector?”. Is it for business or for personal enjoyment?  Will you be showing Excel spreadsheets and PowerPoint presentations or DVD’s and videos?  How much of a stickler are you about        picture quality?

2. The next question should be, where will you be showing these images and how much space will you have?  Will they be shown in an office setting (the same set up each time), at home or in a classroom?  Will the lighting be dim or will it be ambient office lighting?

The responses to the above-mentioned questions, effect the recommendations of which projectors are best for you.

resolution

Resolution: One of the most important aspects to consider in your decision.  Resolution is the number of lines of pixels the projector has available to display an image.  The pixels are organized in grid-like formation (matrix), in columns horizontally and vertically. The resolution is categorized as either a two-number classification (each number separated by a “x”) or a one number classification.  When looking at the two-number classification (like 1920x1080), the first number listed (1920) represents the number of pixels available in each row of pixels, horizontally on the screen.  The second number (1080) represents the number of pixels available in each column vertically on the screen. The more lines the better the resolution or the clearer the picture. In the case of the one-number resolution reference (ex: 1080p), that number represents the number of pixels available vertically (vertical resolution).  This number is equivalent to the second number in the two-number classification (ex: 1920x1080).  The cost increases typically as the resolution increases; as I mentioned the higher the resolution, generally the better/clearer the image.  Projectors come in various resolutions. There is SVGA, XGA, WXGA and WUXGA.  There are more, but I will focus on these.  Generally, I would say this list is in order of increasingly higher specifications.

types of resolution

SVGA: Display resolution is 800x600 pixels=480,000 pixels.  SVGA projectors offer a decent quality projection of image for textual and simple graphic presentations.  They are not good for large projection screens, since the resolution is not amazing.  If one did choose to expand the image to fit a large screen, the image would appear more pixelated.  (4:3)

XGA: Display resolution 1024x768 pixels=786,000 pixels.  XGA projectors are good for business, Church, power point & media shoutout, allowing one to sit closer to the screen without seeing pixels.  They are typically under 3 lbs. and thus quite portable.  768 is compatible with most laptops, computers and DVD’s (international standard format for HDTV, full HD & non-HD digital television & analog widescreen tv), therefore it is good nowadays for home theater as well. (4:3)

WXGA: Display resolution 1280x800 pixels=922,000 pixels.   WXGA projectors provide a good resolution with a wide screen.  This kind of coverage puts you in good stead to move into the future, technology wise.  It has a wide screen and enough pixels and rows of pixels to effectively view spread sheets and video too.  They are available for those with a moderate budget; it does not provide the full resolution of HD, but is still great for home theaters. DVD’s and Blu-Rays.  (16:10)

WUXGA: Display resolution 1920x1080 pixels=2,073,600 pixels.  WUXGA projectors are usually heavier (by about 5 lbs.), but pack home theater quality.  The home theater quality also sports a home theater ticket, coming in more expensive than the WXGA.  This projector definitely seems to require space however.  WUXGA projectors have the highest resolution that customers would typically purchase.  They are good in larger venues.  (16:10)

 

 

other less important factors

Native/True resolution: The number that comes after the equals sign on each resolution type listed above is the Native Resolution.  This is the maximum amount of horizontal pixels times the maximum amount of vertical pixels, therefore this number cannot increase.  It remains fixed.  Using the SVGA display resolution as an example-800x600pixels=480,000pixels, the native resolution is 480,000.  It is good to choose a projector that mirrors your computers resolution, though it is not necessary.  So if you use a computer that has 600p resolution, well then it would be good to get a SVGA projector which will have a native resolution of 600p as well. 

Scaling: Is a process the projector runs to convert a non-native input format to its own native output format.  This process is not perfect, but has improved to the point where it works well and the picture is really pretty clear.  You do always lose some quality when you scale though.  It is more obvious when dealing with data like spreadsheets or PowerPoint presentations.  Typically, it results in a little softer picture. 

NOTE: Tricky Advertising Language Regarding Scaling: When you talk specs of a particular projector, there are terms that are commonly used that can be confusing. Here are some below clarified.

HD Ready – means that the projector has to be equipped to display at minimum 1280x720 without scaling

Full HD - means that the projector has to be equipped to display at minimum 1920x1080 without scaling.

Ultra HD/4K - means that the projector has to be equipped to display at minimum 3840x2160 without scaling.

Aspect Ratio: The Aspect Ratio is a ratio between the projected screen images width and the projected screen images its height. 

Image courtosey of  Best Buy

Image courtosey of Best Buy

There are commonly three ratios that we most frequently discuss, those are; 4:3, 16:9 & 16:10.  The image a screen with an aspect ratio of 4:3 produces is fairly square.  16:9 & 16:10 aspect ratios produce a rectangular image. There 4:3 is associated with XGA & SXGA formats, 16:10 with WXGA & WUXGA and finally, 16:9 standard HDTV &1080p.  4:3 is like a standard analog tv screen.  16:9 is what HDTV uses.

There is also a lovely link, I found that The Projector People put out to help their customers understand this concept. 

Lumens: When choosing lumen output, there are several aspects to consider like the ambient lighting or lack thereof, the type of material the image is being projected onto and how big of an image is going to be projected.  1,000-1200 lumens may be enough for an in home theater where you have the lighting low or dark.  Whereas, 2,00- 3,000 is good for office lighting.  I have read that about 3,100 lumens is the beginning of a good output for office use with ambient light. 

Wireless: Seems to be a poor option unless you are in an area that has reliable Wifi, since you are reliant on this Wifi for optimal function.   

IMAGING SYSTEMS

These are important…only if they are important to you.  Below should help you to understand the most common imaging systems better. 

DLP: DLP or Digital Light Processing (not Disneyland Paris) Projectors use semi-conductor chips called Digital Micromirror Devices (DMD).  These DMD’s have a matrix of tiny mirrors smaller than a blood cell that reflect light from the light source onto a screen (by way of a lens).  DLP uses a spinning color wheel too, so often when you have moving parts you risk more of a chance for things to wear and tear.  DLP typically has better image quality than LCD, but doesn’t last as long.  DLP also is more likely to produce a rainbow effect, though this does not bother many people, in fact, many do not even see it.  DLP has less screen-door effect than LCD.

LCD: LCD or Liquid Crystal Display, uses a high intensity light to shine through the LCD screen.  This light then goes into a lens that projects an image onto the viewing screen.  LCD are great for those on a budget.  Typically lasts longer than DLP and is a little more reliable since its parts are stationary.  DLP uses a spinning color wheel and micro mirrors, so those moving parts of course are more susceptible to wear and tear.  If you are living or working in a remote area, where it is more difficult to access parts or a repair store, it could be more of an issue. You will not typically experience as much rainbow effect from LCD, but there is more of a chance of experiencing the screen-door effect. .  3-chip LCD’s are also available.  3-chip LCD’s give better color saturation, are quieter and better for movies.  The downside is that you have to maintain the filters.

LCoS: LCoS or Liquid Cryistal on Silicone (aka-SXRD:Silicon X-tal Reflective Display-as Sony has named it), is less known about, but has some real benefits.  LCoS uses a reflective technology also, but the light gets reflected onto a silicone-backed LCD panel instead of mirrors. It seems that it is very low on production of screen-door effect and rainbow effect (since there is no color wheel).  This is a high-end multimedia product.  It is really for the aficionado.  

Examples of Rainbow Effect & Screen-door Effect

Image courtesy of  AVS Forum

Image courtesy of AVS Forum

Image courtesy of  AVS Forum

Image courtesy of AVS Forum

 

I hope this is enough to get you going in the right direction!

 

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