Toshiba 53HX71 and Vertical Compression?? (1 Viewer)

[Harold A]

I was taking a look at the manual and reading about the 2 different vertical compression modes : Letterbox and Compression.
In letterbox mode it states the picture is horizontally stretched. In compression mode the picture raster is vertically squeezed. Both modes give you a letter box picture with bars at top and bottom. It says that there is a greater chance of burn-in with compression mode then with letterbox mode. It the raster is being squeezed how does that increase your chance of burn-in?
Thanks

 

[Jeff D.]

Harold:
Toshiba is achieving two separate (and yet seemingly the same) things with these two modes.
1. Letterbox mode has been designed to address the issue of burn-in, which is so feared among potential RPTV customers.
In this mode, the set basically "downconverts" (as a DVD player would downconvert) an anamorphically enhanced widescreen image so as to properly proportion it on your screen. The remaining space on the top and bottom, where we would normally expect to see black bars, is actually filled with gray bars. Gray bars are designed to lessen the effects of burn-in, though it should be noted that excessive use of gray bars will still cause burn-in.
In this mode, the TV also very slowly shifts the image up and down slightly - another way of trying to minimize the potential for bad burn-in.
The disadvantages to this mode are the loss of resolution caused by the downconversion of the image. Also, the gray bars are more annoying than black bars. The image movement shouldn't be a concern - it happens very slowly.
While Toshiba's efforts to minimize burn-in are honourable, it is important to note that excessive viewing in this mode, even with all the safety precautions, can still cause problems.
2. Vertical Compression. This mode is much different. Here, you essentially have "one button access" to the infamous "squeeze" trick. Here, the entire raster is squeezed down to proper proportions for 16:9 display. All anamorphically-enhanced DVDs will be shown in all their glory with their inherent extra resolution and black bars on the top and bottom. This would be the preferred mode for most videophiles.
Burn-in is still an issue in this mode, however. Yes, the raster is being squeezed. But remember what burn-in actually is - uneven phosphour wear. The phosphours are located on the face of the CRT itself. When you engage the vertical compression, the CRT is still the same size and the phosphours remain in the same place. The raster has simply been changed - but now only the phosphours in that 16:9 area are being used. So the potential for burn-in is still there.
Ultimately, responsible TV viewing should not lead to burn-in. Responsible viewing includes:
1. Immediately reducing Contrast and Brightness to appropriate levels. Use of a test DVD such as Video Essentials or Avia would be the best methods. The usual result is a Contrast setting at 20-30% of its maximum.
2. Avoidance of extended viewing of television channels with stationary images (such as station logo "bugs").
3. Avoidance of extended viewing of video games with stationary images (score boards, power bars etc.).
4. Avoidance of extended viewing of any other image with stationary images, including widescreen DVDs with black bars.
As long as you don't exclusively watch anything with stationary images, you should be fine.
----
Jeff
------------------
"They're coming to get you Barbara..."

 

[Ian Bernard]

Responsible tipes number 1, 2, and 3...no problem.
But number 4 is what I've never understood. Any burn-in I've ever seen is the result of bright colors etching themselves into the phosphors. How can black be responsible for burn? What is "excessive" viewing of letterboxed movies?
Right now I only have a Panasonic 27". I'm looking into getting an RPTV. 90% of my viewing time is widescreen movies. I don't put a lot of hours on my set, but in over 5 years of watching letterboxed films I've never had burn in from black bars!
Thanks in advance for your help in clarifying this confusing issue,
Ian

 

[MichaelG]

Ian, the burn-in is not coming from the black bars area, but from every where else. So what would happen is that everything except the black bar area would wear quicker. This is the reason Toshiba burns gray bars on the sides of 4:3 material, to try an deven out the burn across the entire screen.
I have a 4 year old 56" widescreen that I calibrated immediately after buying, the contrast after calibration is about 35-38 and I have played a lot of 4:3 material (at least 50%) since I have had it. I see NO burned in lines on my TV. I have also played plenty of hours of 2.35: material on my set without any hint of burn-in. I think that the key is to properly calibrate your TV set immediately. If you buy a RPTV, the first thing you should do is turn the contrast level down to at least 40% after turning it on.
If you have any other questions just ask.