AVS Forum banner
Status
Not open for further replies.
1 - 20 of 27 Posts

·
Registered
Joined
·
153 Posts
Discussion Starter · #1 ·
I have a NEC 6 PG Plus. My ceiling is too high to mount the pj on the ceiling so I have it on a tall stand in the back of the room. I felt I was pushing it too hard that way because the brightness was almost at 100 and contrast was at 75. I moved the pj much closer (and lowered it so I could see over it). I also recentered the raster and the image on the raster. Now the picture is too bright. Black levels are washed out even with the brightness at zero. I'm thinking I adjusted an unknown (to me) mechanical brightness pot or other type of adjustment. Is there a mechanical brightness adjustment for a 6PG plus? Or is the only adjustment done via the remote? I noticed I gained quite a bit of brightness when I centered the raster. Maybe it was so far off that this made a huge difference. The way it is now I will have to move it back where I had it in the back of the room to get the black levels back to normal. Any opinions?


thanks
 

·
Registered
Joined
·
876 Posts
Peter,


You don't just move the projector back and forth in the room. These projectors have specific throw distances for a given screen size that needs to be followed. For instance, a 92" wide screen (and I wouldn't go wider for a Plus) calls for a throw distance of right at 130" for your projector. No offense, but I think you should spring for a professional to come out and properly setup the projector for you. Regards and good luck.
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #3 ·
I'm aware that there are specific distances for specific screens. That is the ideal set-up for the ideal picture. I can't put the projector at 130" from the screen. It is on a tall stand and I would be sitting in front of it which would put me too close to the screen. I appreciate the sentiment, but I do not have an ideal situation so I have to make compromises. By moving the projector back I will use less of the phosophor area to make the image fit on my screen. I don't want to do this, but unless I can learn how to get the brightness to an acceptable level (the subject of my post) in its current position on a low stand closer to the screen, I will have no other choice but to try the projector in the back of my room (again). My two choices for placement of this projector are in front of the couch on a low stand or behind the couch on a high stand. I've tried both multiple times. I will do the numbers again and see if I can get it at the ideal distance for my screen, but I don't think it is possible. Off the top of my head I think 123" is the distance for the projector from my screen.
 

·
Registered
Joined
·
567 Posts
All brightness and controls are done on the remote.


Get yourself an AVIA or Video Essentials DVD and it will guide you through setting up brightness, contrast, sharpness and hue.
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #5 ·
My brightness is set at 0 using the remote and black level still isn't black enough. Is there another brightness setting?


I've never adjusted sharpness and hue on the projector. I didn't think there is a single adjustment for either of those settings. I thought those properties were a combination of settings on the NEC 6PG plus and other front projectors. I am wrong about this? Is there a single setting for sharpness and a single setting for hue?
 

·
Registered
Joined
·
567 Posts
If you are using the RGBHV projector inputs then the only controls on your projector which are available are constrast and brightness. Sharpness and hue are adjusted at the video source.


With brightness at zero can you still see the rasters lit up? What about with no video source attached.. are the raster still visible.


Perhaps your contrast/brightness need adjusting at the video source.
 

·
Registered
Joined
·
876 Posts
Peter,


If that's the reality of your situation then I have to recommend that you get a digital projector with a long throw option. What you're doing with a CRT projector will shorten its life and yield an unsuitable image. To use less phosphor means you'll have to overdrive the projector to achieve proper light output. You've (unfortunately) purchased the wrong product for your application.


It's not about "the ideal setup for the ideal picture". It's about using the machine within the operating parameters that it was designed for when it was engineered and produced.


BTW, it sounds like your drive (G2) controls are set way to high. You didn't touch anything around the white focus block, did you?


BTW, I'm not a novice at this. I do this stuff for a living (custom home theater). Good luck.
 

·
Registered
Joined
·
3,480 Posts
It sounds like you have to hang the PJ from the ceiling to do what you want, but are getting a little lazy about it. Get yourself a 1.5"X20' piece of ridged metal gas pipe, weld one end to the PJ and bolt the other end to the ceiling. There that was not so bad, now was it?


Just kidding.


But you should try and hang it from the ceiling as this would solve your problems.


Deron
 

·
Registered
Joined
·
449 Posts
if you have 0 brightness and you still can see raster,you can adjust

G2 of three guns to lower the brightness,you can also do white blance,and lower the black level of three color!


by the way,what source did you hook on,are you use a external transcoder for component video? some transcoder will lead this problem!


good luck!
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #10 ·
Bill,


I understand you aren't a novice. I've read many very helpful posts by you. This projector is better in price, value, and performance compared to a digital projector. Even when this projector isn't used in an ideal way. My reality is that I have this projector, I don't want to spend my money on a digital projector (nor can I really afford it) , and I want to make the best of a less than ideal situation. That is my personality. Things in life can't always be ideal, but through some creative thinking, they can usually be made to be pretty good. I'm okay with pretty good. That is my goal with this projector. If you can give me some advice or information that might help my current situation I would appreciate it immensely. Suggesting to me that I should buy a digital projector, well intentioned that it might be, isn't going to help me. I plan on getting a couple of years of use out of this projector. I think I will be able to do that with my setup (especially with the help I get here.)


Now, on to the important stuff, the details. The projector came to me with the rasters on all 3 tubes already with a burn on them. It was probably used in a classroom or similar situation. Even with the burn the picture is still very good. When only the raster with the burn is used the difference in white isn't obvious. I think part of this is because the mind tells me that something that should be white is white (even though it isn't). When more of the raster is used then it is obvious that white isn't white on the used portion of the raster. Put on Fargo and the outside third of the picture is white and the middle two thirds is pink. Oh well. I can work around that. My focus right now is my brightness problem.


I don't know which controls are the drive (G2) controls. I don't know where the white focus block is. If you can describe them for me then I can figure out whether I touched them or not. And then I will try to get them back to a normal position if they are not in a normal position.


Cookie,


The video source is a very interesting suggestion. I will have to look into that. I use a crystal image scaler connected to the projector via RGBHV BNC connections. I hadn't thought to check the scaler. I will do that.


My brightness is at 0. I can still see the picture on the screen. The rasters are definitely lit up. I don't know what I did to cause this. Last week I moved the projector off a tall stand. It was about 150" from the screen. The brightness was at 100 and contrast was 75. Even at these settings the black level was still a little too dark. That is why I moved the projector. I moved it to a short stand and put it about 70" from the screen. I wanted to see how close I could get the projector to the screen with correct geometry and a decent size. I expected the size would be smaller than the screen. I'm okay with that because I don't want to push the projector too hard with the brightness and contrast. Once I had it on the small stand I centered the raster and the image in the raster using instructions from a Guy Kuo post. After the move and centering the raster the picture is too bright (washed out picture, blacks too high - my estimate is that the blacks are at 20-25 IRE). This is with the brightness at 0. The projector is now at 95" (still on the short stand) because there wasn't enough keystone adjustment to get the picture 'flat' with the projector at 70" on that short stand. I wouldn't have expected such a large difference in brightness just from centering the raster and moving the projector 55". I suspect that I must have done something to an adjustment I'm not aware of that changed the brightness drastically.


When I get someone to help me I will take Bill's suggestion and move the projector (tall stand) to the specified distance for my size screen and see if I can sit in front of it and not be too close to the screen. If that doesn't work out I will put it where it was at 150" in the back of my room. I still think the brightness will be off though so I'm looking for brightness suggestions.


I didn't think I could adjust sharpness or hue and you confirmed that.


thanks
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #11 ·
deronmoped,


I wish I could ceiling mount the projector, but the ceiling is too high. If I had a place with an attic above the ceiling then I would do it.
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #12 ·
I now think I know what the G2 controls are. I learned this from another thread. It said they are on the white block that has a plastic cover with a red plastic sticker on them saying "Warning: Do Not Touch". It looks like they are 3 adjustments. I have never touched them. I am sure of this.
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #13 ·
I just looked at the menu of the crystal image and all of the video adjustments are at the midpoint. They have not changed since I moved the projector.


So it looks like it isn't the G2 controls nor is it the scaler causing my brightness problem. Any other suggestions?
 

·
Registered
Joined
·
569 Posts
The G2 controls are labelled R, G, & B and are over the blue gun. On the 6000 it is in a white plastic block.


Realize that you are adjusting the overall "mix" of each color here -- each gun's relative drive levels. It will affect grayscale. You might not care, though. If you are already experiencing haze from burn-in then your grayscale might be way off to begin with.


By adjusting the G2 controls in combination with the electronic White Balance controls you can regain a livable picture (at least closer to what the projector has to offer). It is just going to take a lot of trial and error without a color meter.


A good external grayscale test pattern is a must. You can fake it by turning down the color saturation on your input source. Turn your electronic Bright and Contrast to 50. Turn your electronic White Balance controls to 50W 50B for each color.


Adjust each G2 control down so that all guns are off. Be careful not to flare the tube. If you turn it up to high, get it down as fast as you can. Did all three tubes start to flare near the same place in their pot's rotations? If they don't then there may be wear to consider.


Start by turning up the green pot to a point where the area of the screen outside of your source's picture has no haze or light, especially on the left and right edges. No flare should be visible. If haze from burn-in is evident then turn it down slightly.


Bring up the red until there is no such thing as red and there is no such thing as green. Everything should be orange/yellow. If the whites look one color and the blacks look another, that's allright. We'll fix them later with the White Balance controls.


Next, bring up the blue. Watch the teeth. Don't turn it up too high.


Look okay? Okay, then leave the room. Go outside. Look at something real. By this time your eyes have already started to "Adjust" to your projector.


When you come back, make any final adjustments to the G2 controls so that you don't have any over-driven colors and close it up.


The next series of adjustments are made using the White Balance controls.


A sixteen step or greater gray scale is necessary for this step. Starting with each color at 50, adjust each color's W balance so that the brightest color square is white. Now do the same thing with each color's B balance using the darkest square(s).


Work your way down from the ends of the scale slowly working your way so that all scales are as close to gray as possible. If it seems that one color is way off from the others, then you might have to adjust that gun's G2. Be aware that you have already adjusted this and turning it up higher might be overly bright. If you are compensating for burn-in be aware that this could/would just make it worse.


Well, that's how I do it.
 

·
Registered
Joined
·
569 Posts
Have you tested with other sources?


If it is better on another source then your problem is probably the signal from the scaler. If it is the same then you might have to touch the G2.


What settings is your White Balance set to?
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #16 ·
Teran,


Thanks very much. I've never tried to adjust the color because I didn't know how to go about it. I just let the auto function on the projector do the best it could. I have Avia and VE so if I'm feeling up to it I might try your instructions. If I can mark the G2 controls where they are now then I probably will give it a go.


thanks
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #17 ·
Teran,


The only sources I can use to check go through the scaler. My options through the scaler are the DVD player or a cable box. Both look washed out.


In the menu all 6 white balance adjustments are at 50% (2 each for R, G, and B).
 

·
Registered
Joined
·
569 Posts
Do you have an s-video input on your projector so you can go directly from our DVD?


You don't have to have a memory setup for the s-video. It doesn't have to be converged, just tested for brightness and contrast.


The alternative is a computer monitor that can take an input from your scaler.


You have to rule out the scaler. It isn't worth touching your G2 controls otherwise.
 

·
Registered
Joined
·
4,533 Posts
PeterF,

Slow down, dont move the G2s yet, you have a lot more to look at, if you move the G2s it will cost you in the long run for a recalibration of the reference white balance. Look at the termination of the video signal, or an open port, there is a reason that its to bright, you just need to find it. If you had a decent picture before then Id say to leave it alone and dont push their buttons, projectors are female and will end up costing you if you mess with them. Doug
 

·
Registered
Joined
·
153 Posts
Discussion Starter · #20 ·
Doug,

I wasn't planning on doing anything to them yet (or at all - it is just one more part of the information puzzle). I didn't think they were the cause of the brightness problem since I didn't touch them. I want to figure out that first. I am pretty happy with the color balance the way it is. That's a great line Doug.


Teran,

I don't have a svideo connection on the projector. I could hook up a computer to the vga port on the scaler, which is suppose to pass through the signal, but I'm not too kean on that idea just yet.
 
1 - 20 of 27 Posts
Status
Not open for further replies.
Top