Quote Originally Posted by EdwardGein
I originally had a 27" regular TV for my bedroom about a year ago & I thought I'd replace it with an widescreen HDTV about the same size. The prices were about right. When I actually went to soem stores looking at them, thank God I didn't order one online sight unseen, they're way to small, much relatively smaller than my 27". I wouldn't get one smaller than a 30" HDTV.

Can someone explain to me again, what the visual difference is between say a 30" CRT widescreen HDTV and an LCD one?
TV screens, regardless of the type of technology used, come in two standard aspect ratios in the U.S. The old one is 4:3, and the new is 16:9. The first number in each represents the width and the second the height. It is good if you can remember your high school geometry, with the Pythagorean theorem of:

a2 + b2 = c2

where "a" and "b" represent the legs of a right triangle, and "c" represents the hypotenuse (which is the "diagonal" or the line opposite the right angle). With TV sizes, they are given as the diagonal measurement, regardless of which aspect ratio one has. To find out the actual width and height on a particular screen, you will need to know which aspect ratio the TV has, and then plug into the formula for "c" whatever the size is listed as being. Thus, with a 4:3 aspect ratio, one uses the formula:

(4x)2 + (3x)2 = c2

Solve for x, then 4x will be the width, and 3x will be the height.

For a widescreen TV, one uses the formula:

(16x)2 + (9x)2 = c2

Solve for x, then 16x will be the width and 9x the height.

To give an example, a 27" TV that is 4

(4x)2 + (3x)2 = 272

16x2 + 9x2 = 729

25x2 = 729

(Notice that on the left of the equation, so far, nothing about the TV size has entered the calculation, so one can use 25x2 = c2 for 4:3 TVs.)

x2 = 29.16

x = 5.4

Thus, a 27" TV will be 21.6" wide and 16.2" tall.


An example with a widescreen, say a 32" that is 16

(16x)2 + (9x)2 = 322

256x2 + 81x2 = 1024

337x2 = 1024

(Notice that on the left of the equation, so far, nothing about the TV size has entered the calculation, so one can use 337x2 = c2 for 16:9 TVs.)

x2 = 3.04 (this is rounded)

x = 1.74 (again, this is rounded)

So the 32" widescreen TV is approximately 27.84" wide and 15.66" tall. Notice a 32" widescreen TV is slightly smaller vertically than a 27" 4:3 TV, so if one is using a 27" 4:3 TV now, and is switching to a widescreen TV, one must get a widescreen TV that is larger than 32" in order to not have ordinary (NTSC) TV broadcasts any smaller than that to which one is accustomed. Obviously, the 32" 16:9 TV will show a much larger widescreen image than a 27" 4:3 TV.