CurtPalme.com Home Theater Forum

[tri_joel]

So I have been trying to improve my set-up on my BG 1208/2. I have not been able to get a good focus, which is why I decided to start from scratch. I have HD145s with DIY lense adapters made from plexiglass and epoxied to the lenses. The tubes are snow-white and from what I can tell they were replaced in the projector and never used.

First I deleted all blocks and then reset everything to mid-position.

I have been using gen-locked test patterns, so my first question is should I get DVE or something for set-up? I cannot, for the life of me, get the magnetics lined up properly. The blue seems to be the biggest problem, I cannot get rid of (what I call) ghosting.

Any suggestions where to start?

[Curt Palme]

Ghosting usually is a signal issue, not a focus one. Also called ringing.

I set up an 808 from scratch in a home the other day.

-put contrast at 100
-defocus each color slightly electronically, then look into the tubes and set astig so you get round dots.
-set electronic focus on the tube face while looking at the tube faces with sunglasses.

Once the tube focus is good, leave that alone, and concentrate on the optical and scheimpflug while watching the screen.

[Curt Palme]

Ghosting usually is a signal issue, not a focus one. Also called ringing.

I set up an 808 from scratch in a home the other day.

-put contrast at 100
-defocus each color slightly electronically, then look into the tubes and set astig so you get round dots.
-set electronic focus on the tube face while looking at the tube faces with sunglasses.

Once the tube focus is good, leave that alone, and concentrate on the optical and scheimpflug while watching the screen.

[zGman]

The Internal Barco patterns do not have symmetrical dots, you need a external pattern
to do astig correctly - an extron generator running at low resolution (408P)is ideal for this.

[tri_joel]

I played some with it today, I got the round dots and the problem has improved - but not corrected.

This photo is pretty accurate representation of what I see on the screen. Notice the blue and green around the left side of the white shirt. Also notice how out of focus and dark.

I can't afford a pro calibration and set-up right now, I would like to get a better picture if possible. Any ideas? What am I doing wrong?

[/img]

[ecrabb]

Joel - what does the image look like if you take a lens off and look closely at the tube face? Use a pair of sunglasses if you need to.

SC

[JustGreg]

Seeing as I'm out of lurk mode tonight I'll toss this out there if for nothing other than to learn from. (A friend has the exact same model as the OP and I'm thinking about getting it when he moves so this is good info.)

I have a Marquee. I've owned a BG but never installed it. But if some things cross over I'd have to say that flapping isn't the problem...at least with the center of the image. It looks like a mechanical or electronic focus issue to my untrained eyes. The center should at least be sharp (disregarding the obvious convergence mess) IMO.

There's alot of free patterns you can get. I know Clarence has a slew of them (or did) because I have everything the man ever made public.

I've often wondered how much of a PITA it is to replace the inferior (for our needs) internal patterns with more accurate ones. I realize most everybody has a copy of DVE or the equivalent but it seems to me that the shorter the bus the better...in that video subsystems and external sources would either be outside consideration for setup or aid directly in ruling out the onboard video segment as the problem.

[tri_joel]

I'll take the lense off tonight or over the weekend and check it out. The problem is much better after following Curt's instructions above. I may spend a few hours this weekend and do it all from scratch again.

I have put very little effort into convergence.

Here is another shot, notice the horizontal red streak running across mid-screen?

[Ile]

Can't see your picture here at work, but...

If you haven't adjusted focus yokes position, that is something to try.

Elevate contrast to 75 to help seeing focus better.
Adjust center focus zones to 57 from focus menu and move focus yokes along tube neck to find sharpest position.
Then redo optical focus and test center astig with center focus, by under and over focusing. If dots are circular and core is at center of the blob you can now adjust center focus from menu to sharpest position (defocus blue +10-15 clicks to get rid of blue hump in grayscale). Adjust now other focus zones and then tweak dynamic astig from service menu to get circular dots also to edges. Drop contrast back to normal level and reconverge.

Made this last night and got good improvement to red and blue focus. Blue didn't meant much since it was needed to defocus some amount to get proper grayscale measured, but now I have red and green equally focused. I made all these adjustments by looking to screen and it was also needed to walk "few" times to look closer, so friend or video camera/monitor would make adjusting easier.

[stefuel]

You can start by turning down the contrast. It looks like it's blooming.