Rear projection TV
decision
How to decide on rear projection TV
Things to consider
When you come to decide on actually buying a rear-projection TV, make certain you include these factors. I'll take you through some details to help in deciding -
What you'll watch (and where you'll watch it)
Brightness
Contrast Ratio
Pixel Density
Colour
Reproduction,
Inputs
Viewing Angle; and
Price.
Brightness
Without enough brightness an image will look weak and soft, even in a
darkened room. Check the Lumens rating. Projection assemblies giving out 1,000 ANSI Lumens
is easily enough for a rear-projection TV. But, because the light is reflected onto a screen, the
light intensity coming from the screen (into your viewing room) is more important.
The brightness coming from a screen surface is calculated in cd/m2 (Candela/Square Meters).
It's also called 'nits'. The measurement of brightness on rear-projection TVs can vary widely. You
can get, anywhere from 400 to 800 cd/m2. This should be labeled in the specifications
sheet for the TV. It might also be found as Foot Lamberts(fL), where 1 fL is approximately
3 cd/m2.
Don't get caught up in the maths. The bottom line is: Just make sure you are comfortable with
the brightness of the image on the screen.
Contrast Ratio
Contrast ratio acts with brightness. High contrast ratios give whiter whites and blacker
blacks. A rear-projection TV can have a great Lumens and Foot Lamberts rating, but if the
contrast ratio is low, your image will look washed out. A Contrast ratio of at least 1,000:1 or
higher is of excellent standard.
Pixel Density
Pixel Density is very important for LCD/DLP units. As I mentioned earlier, LCD and DLP-based
video projectors have a certain number of pixels on their display chips.
If most of your viewing is HDTV then you should get as high a native pixel count as you possibly
can. For instance, 720p HDTV signals need a 1280x720 pixel count to give you a one-for-one
representation of a 720p signal whilst a 1080i HDTV input signal needs a native pixel count of
1920x1080 for a one-for-one representation of the 1080i signal.
If a projection set's pixel count is less and it accepts HDTV input signals, the signal is scaled
to fit the number of pixels on the chip. However, a native pixel count of 1024x768 is enough
for DVD. Also, some projection sets will upscale a lower resolution image to match a higher pixel
count on the chip. Scaling works both ways. You should check specifications to see if it has that
capability.
Colour Reproduction
Look for natural flesh tones and depth of colour. See how the colours look in the brighest and
darkest areas of the image. Check the degree of colour stability from input to
input. Each of us has a slight difference in our colour perception and what looks pleasing. Just
look carefully.
Viewing Angle
Every projection TV has a problem when you view from the side. Even though viewing
angles for rear projection TVs have improved a lot in recent times (some giving 130 degrees or more)
the best is still from the center of the screen out to a 45 degree angle, with acceptable viewing possibly
out to 90 degrees. In other words, all the viewers sitting on a large couch shouldn't have a problem, but
someone sitting in a chair off to the side just will not get an good view of the screen.
Inputs
You'll need to be sure that the projector has the inputs you need. Things like composite and S-video for
analogue sources, inputs for DVD, and DVI or HDMI inputs for HDTV. Some rear-projection televisions
now have VGA or similar inputs that allow it to be used with a computer for video or game play.
Price
Rear-projection TVs are just the thing if you're looking for a bargain or an inexpensive way to get that
fantastic big screen HDTV experience. Good news is that prices are still coming down for all sorts and sizes of rear-projection TVs.
Decision time - HD or Analogue
You'll have to decide if you want a standard analogue rear-projection TV, an HD-upgradable set, or
an Integrated HDTV set. To help you in this, look at my HDTV FAQs.
Return to - Projection TV
|
