[toptentwist]




I own a 55" widescreen rear-projection Mitsubishi TV.


It only gives three choices for viewing.


1.) 4:3 with grey bars on the left and right


2.) "stretch" - pulls the 4:3 image to fit the screen

but distorts the picture (everyone now looks short

and fat)


3.) "zoom" - cuts off the top and bottom and blows up

the rest (picture is now too fuzzy and you miss

things like the top of people's heads)



The 2nd option works well for anamorphic DVDs.

The 3rd option is what I used to use for letterbox

(non-anamorphic) DVD



Recently, however, I realize I have two additional

options.


1.) I can select a PIP mode that moves the 4:3 to

the extreme left and then puts three small 4:3 squares

on the right. The main image is no longer centered,

but there's no longer two 2:9 grey bars (which are

distracting). I get this extra stuff on the right

but the main image is no longer distorted

and I apparently don't have to worry about burn in

because there is a constant movement on the entire

16:9 surface. I've found for music laserdiscs

(which are usually 4:3), if I set the PIP so

that the laserdisc is selected for the main image

AND the laserdisc is the PIP input, I end up

with a wierd time-delayed repeat of the music

images on the right. It actually seems cool

this way. Kind of like a "video wall" in

a bar or a store...


or



2.) I do the same as 1.) - but I set the PIP

input to a source that isn't on (like my SVHS

recorder). This makes the three little 4:3 squares

go black. So I end up with a 12:9 (aka 4:3) image

on the left and a 4:9 black bar on the right.



My biggest concern is that the 4:9 black bar puts

a strain on the television more than those grey

bars - which are apparently there for a reason -

but not one I really understand.



Wouldn't a black image translate into nothing being

sent from the guns ? (hence no danger of anything

being burned into the screen)


On the other hand, I understand that a grey signal

would sit at 50 IRE - exactly halfway between 0 IRE

(black) and 100 IRE (white) - thus minimizing the

work that a signal has to do to get to some point

between 0 and 100 (at most a 50 IRE "swing" - versus

a "swing" that can vary between 0 and 100)...



Is it the swing being sent to the guns that wears

them out ? I thought in the old days on a CRT,

it was the electrons hitting the phosphers on a CRT.



I'll admit that I really don't understand how

a rear projection TV works. Something about

colored light hitting mirrors and then being

projected onto the back of a screen. But thats

harder to imagine than a beam of electrons hitting

little green, red, and blue dots...

 

[AJSJones]

You're partly right : The light that goes to the mirror(s) comes from the 3 CRTs - the phosphor surface in those CRTs will slowly degrade and if you have no electrons hitting the phosphors (when viewing 4:3 on a 16:9 screen) in the "bars", they will wear less than the 4:3 area. Then, when you watch 16:9 stuff, the area where the 4:3 image was will be on a more "burned" area of the CRT and will be slightly less bright and its color will shift as the different phosphors age differently. The reason for the gray bars is to maintain those areas with a similar amount of phosphor wear to the area of the 4:3 image, so you can watch 16:9 later without uneven brightness and color. A certain amount of distraction is unavoidable (I don't like stretching or chopping the image, to me this is more distracting) because 4:3 and 16:9 are just different. You have to make your own choice of what is least distracting and balance that with the fear of burn-in if you have black bars, which some find less distracting than gray ones. A variety of threads have addressed this before and some use the gray bars to protect the CRTs and have black curtains to cover them. Very hard to put a number on the phosphor wear and how much to worry about it. It is certainly more of a problem if the contrast is set too high and less of a problem if the set is calibrated to drive the CRTs to the RIGHT level (and there is a RIGHT level - calibration DVDs like Video Essentials or Avia can help here)


Andy