I used Doug's guide to do astig on the green. With focus all the way down, the dot is in the center of the flare. With focus all the way up, the dot is round. So basically, the dots are near perfectly shaped in the center. However, on the top left and bottom right corners, as well as the far left and right edges, the dots are very triangular and I cannot correct this with electronic adjustments. Any tips?

By the way, after doing the 4 pole adjustment, the dots were still ovalish, flaring to the bottom right, but only with focus all the way down. When focus was all the way up (as Doug suggested to do in his guide for the 4 pole magnets) the dots were round. Does this mean anything?

This can be a bad focus board or a bad wave board. I've had both cause this. Seems to be very set dependent. Some tubes/chassis focus way past what you'd expect, some you fight with for hours..:(

You don't check 4 pole dot shape with focus all the way down or 6 pole. You can do some fine tuning by using the actual image and use a full data field or 1:1 bitmap that the guys use for resolution.

In astig hit test - end to use the actual image. Do this with optimum focus then go back and do edge and corner focus again.

You can have something going on but its not out of the norm to have some oddities with the internal dot test pattern.

This takes much patience as well as knowing phase and its affects. Then there is expanded raster and doing past what the lenses can do or what the electronic was designed to do.

As a thought I have seen some all white right edge 'ringing' sometimes called banding on some of the screen shots of different bands, this will also have some affect on astig shape. You do what you do to overcome it. Porches, raster shift etc mostly on 1920.
If the optical core is perfect as well as image in the center of the lens sweetspot it helps the unbalanced corners on focus. Also the internal test patterns are overscanned 10% and not in the actual image. Doug

yea mine does this also, but only with the green, it did seem to improve a little with F-MG tilt but still not right.

NautikaL,

projectors where the tubes have steep deflection angles exhibit this problem especially in the corners and on the green tube.

If you got your center round and the triangular dots' sides with even length you probably got it close to as good as it gets.

For the corners I do suggest though to do as Doug says and adjust with an actual picture and not with the internal pattern.
For HTPC users this would be some text pattern.

And don't despair if the readability in the corners leaves a little to be desired - movies have little attention catching details in the extreme corners of the picture :)

Oliver

The angle is 12.4° as per the manual. I have the ability to go from 0° to 12.4°, but any less than 5° and the projector is in the way, and any where in between 12.4° and 0° makes setting schiempflug a big trial and error party, something I'm not really in the mood for. Everyone says to read the manual for the NEC, so I just figured I'd follow it and deal with some keystone http://www.xtremesystems.org/forums/images/smilies/thumbsup.gif

But I am a bit close to the screen. Around 106.5" for a 84" wide screen, so a throw ratio of ~1.27. 3" closer than the often recommended 1.3 throw ratio. I can always move the projector forward 3" if I run into more problems... we'll see.

I will try the AVIA dot pattern or something similar in DVE if it has it. Does anyone have any tips for setting the 6 pole? Should I do it defocused or overfocused? I found that it's difficult to setup since just moving the magnets slightly affects it whereas there's more range with the 2 pole and 4 pole.

Thanks guys!

The angle is 12.4° as per the manual. I have the ability to go from 0° to 12.4°, but any less than 5° and the projector is in the way, and any where in between 12.4° and 0° makes setting schiempflug a big trial and error party, something I'm not really in the mood for. Everyone says to read the manual for the NEC, so I just figured I'd follow it and deal with some keystone http://www.xtremesystems.org/forums/images/smilies/thumbsup.gif

But I am a bit close to the screen. Around 106.5" for a 84" wide screen, so a throw ratio of ~1.27. 3" closer than the often recommended 1.3 throw ratio. I can always move the projector forward 3" if I run into more problems... we'll see.

I will try the AVIA dot pattern or something similar in DVE if it has it. Does anyone have any tips for setting the 6 pole? Should I do it defocused or overfocused? I found that it's difficult to setup since just moving the magnets slightly affects it whereas there's more range with the 2 pole and 4 pole.

Thanks guys!

I was talking about DEFLECTION angle, not PROJECTION angle :)
This is the angle in which the electron beam hits the phosphor on the sides of the tubes.

The tubes in the G70 and the XG's and PG's have a steeper deflection angle than the tubes in E-Home, Barco and Ampro 8" units that also have a thicker neck.

6-pole is the triangularity adjustment so you should see the effects in both under- and overfocused state. For ease of adjustment I suggest to underfocus as it makes for dots that are easier to see.

Oh :D. I wasn't really sure what you were talking about, so I just assumed projection angle. Excuse my noobyness :o

Also, could this be in any way related to the "FOCUS BALANCE" setting? This was reset to 0 after I had the projector sitting in the basement without power for a few months. What exactly does this do, what are the effects if it's not set properly, and how can I set it (Doug)?

Jeff, it sounds pretty normal.

This is why the Barco 909 has triangularity in the corners.


But you will need to set Focus Balance correctly - you'll need a scope though, and a PC as a signal source (or a test pattern generator, but that's kinda exotic).

This is the first or second time I've heard of an NEC losing it's memory. The memory is non-volatile - it doesn't need power. Did all the white balance settings go as well?

Focus balance is the high speed focus tracking that adjust's the focus from edge to middle to edge as the beam travels different distances from edge to centre to edge, thats why on the scope the signal looks like a parabowlic curve, yes does need to be set to allign the signal to raster trace.

Jeff, it sounds pretty normal.

This is why the Barco 909 has triangularity in the corners.


But you will need to set Focus Balance correctly - you'll need a scope though, and a PC as a signal source (or a test pattern generator, but that's kinda exotic).

This is the first or second time I've heard of an NEC losing it's memory. The memory is non-volatile - it doesn't need power. Did all the white balance settings go as well?

Do you mean the Black Bias and similar settings? I had to reset those with a multimeter. For all I know I could be the fifth owner of the set. Who knows what it's been through. Maybe the board with the memory was replaced? Maybe it was inadvertently deleted?

What's going to happen if the focus balance isn't set correctly? I don't have a scope and I wouldn't even know what to do with one to set focus balance if I somehow got access to one.