CurtPalme.com Home Theater Forum

[jbmeyer13]

Is it acceptable to have a blanking value of 20 for either the left or right? I'm trying to minimize the amount of the picture that is being cut off.

My H size is 90, V size 25 and the raster is centered (so is the phase). My blanking values for top and bottom are zero, but my left is 6 and my right is 20.

[dturco]

You really shouldn't need any blanking. All blanking does is make it so a part of the picture is not displayed by electronic means. Sounds like your set -up is in need of adjustment[s]

See some info from Tim's site.

http://etechvideo.com/techarticle3.htm#

[jbmeyer13]

The problem I’m running into is that if I set my H size at 90 both the grid and source image overlap the tube face; i.e. the source image appears to be really close to the size of the grid. It’ one thing for the grid to overlap the tube face as that is necessary to maximize the phosphor but if the source image area also overlaps there is distortion at the lower left and right edges.

I set my H size at 90 and positioned the PJ so that the grid and the distorted part of the source image overlapped the screen. I then used blanking to compensate. My other option was to set my H size at 75 and then the grid touches the edge of the tube face and the source image is not distorted.

[Nashou66]

What re trace setting are you using?

Does the image go over on both Sides?

Always keep active image within 5-6 mm from the tube edges( I use corners for measurement location)

Do not use the internal Grid for geometry and size set up always use a grid pattern from your source.

Athanasios

[jbmeyer13]

I have decided to go with short retrace. The following photos are with H size at 75 and no blanking. If I expand sizing any more the source image wraps over the tube face.

[Nashou66]

What resolution? I forgot to ask.

Also its best to use a pattern disc from your source. the timings in source units all differ from what the internal patterns are.
You can get close by selecting a internal frequency close to what your source may be but they never match exactly.

You could also use phase to try to center it more.

What I do fist is use a pattern with the over scan pattern on it so you can set size and also see what the difference between short and long retrace is.

Then once you set up the size for H and V and can see how much of the actual image is displayed then go to a grid pattern and do geometry/Convergence.

Athanasios

[jbmeyer13]

My Samsung BD is outputting 1080p/60. When you say you keep 5-6mm from tube edges are you measuring this on screen image; i.e. 5-6 mm between edge of source image and edge of test pattern (white field)?

[Nashou66]

I mean keep the image 5-7mm away from the edge of the tube face. So have the corners of the image that distance from the edge of the tube .

Athanasios

[jbmeyer13]

I obviously assume that you are measuring this with the lens off the tube. If I have 5-6mm between tube edge and source image my H size will be in the 60's...

Everyone has been saying that my H size should be 85-90 but that is impossible. As a contrary point, I was just told today that the values vary from HDM to HDM so I shouldn't use them as a baseline.

[Nashou66]

Right it could be anything, but I would do an Initialization of the PJ to clear all memories incase they might be corrupted.

Athanasios

[dturco]

Yep HDM to HDM width coils can and are adjusted different on each board. My 9500 is running 70 for H size and My width coils are jumped for...... well they've been modded, so they can be an issue. My image is less tan a 1/4 inch from each side of the tube face and looks good and stable with very little ringing [ destabilized image from a short retrace].

Nashou has it it right, as usual, reinitialize and start from a fresh set-up.

Lenses off, adjust image, measure image, then let the sizes be whatever they are.

[jbmeyer13]

I already started fresh so thats not a problem. Just a little pissed that I have been wasting all kinds of time "chasing values" and wondering why I couldn't get things to look right.

Nash- what are you using for a test pattern source these days?

[jbmeyer13]

Since the raster has a trapezodial shape to it the top edges will appear closer than the bottom edges to the side of the tube face. The 5-6mm should be measured at the top; meaning the bottom will appear much further from the side than 5-6mm

[Nashou66]

I use either the Blu Ray DVE disc or the free AVS HD 709 disc over on AVS forums in the calibration forum.

If your image is trapezoidal, as most are that are floor or ceiling mounted , then you only have to worry about the two corners being 5-7 mm's away from the edge of the tube.

Athanasios

[dvh99]

use a vp or a htpc with powerstrip or software from the newer nvidia card which allows for porch settings.
set backporch to minimal 1,7us to prevent ringing.

this way you can shift the raster to the left and keep the active image in the middle and have the biggest possible h-size.
long retrace cuts of part of the picture.

[jbmeyer13]

Yeah, I plan on getting the Radiance to address the ringing via porch settings. For now, I'm doing a direct feed to PJ until I can pick up the XS+ (and output 1080p/72).

[jbmeyer13]

These are shots of the source image from dve calibration disc; H size 52 V size 14. My throw distance is 108" and there is 5mm between edge of source image and edge of tube face.

[Nashou66]

Looks great!!!

Athanasios