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Discussion Starter · #1 ·
Does anyone know (dare to guess)?:


Service Manual:

1. p6, lower left, point 3. "BRIGHT and CONTRAST set to in the Setup Menu"

=>Set to what?


2. p6, lower right, point 6. "GAMMA returned to default in the Image menu"

=> I guess they mean "normal" instead of default?


3. p6, lower right, point 7. "Place the cursor on 0%..."

=> I guess, set to 0% (in the left GAMMA MENU) and use the G field?


4. . p7, point 16. "...color coordinates (x,y)...."

=> I guess these are the intensity values for R and B?


Some Service menu adjustments are not even mentioned in the Manual.

5. Is it correct that Black Ref. sets Bias level to the panels?

How about Sub Bright and Sub Contrast? Sub Bright also sounds like a Bias in the same manner as regular Brightness sets the Black level...
 

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rbrande,

I've wondered about some of those points too. It seems to me that whole section under ADJUSTMENT PROCEDURE beginning at bottom of page 6 and covering the whole of page 7 requires the use of instrumentation. Are you using a camera light meter to take readings?


I'll guess at the first point you raise (P.6 point 3) - BRIGHT & CONRAST set to MAXIMUM(?) in the setup menu. It's certainly not DEFAULT because P6 point 5 states: BRIGHTNESS & CONTRAST is returned to default in the Setup menu.


Default GAMMA is definitely NORMAL. When adjusting the gamma setting in the Setup menu there's no need to scroll down to the bottom of the IMAGE heading if it's NORMAL GAMMA you want. Just move across to the IMAGE heading and press RESET.


I find this whole section a bit confusing. Take point 4 on P6. "Place the cursor on SLIDE SHOW ............ display G monochrome and adjust the luminance at the cetre of the screen." HOW? As far as I can see, there's no way of adjusting luminance in SLIDE SHOW. Furthermore, if one is supposed to adjust it by exiting the service menu and adjusting BRIGHTNESS & CONTRAST, then to what reference point should one be making the adjustment?


I also find it odd that there's no reference in the Service Manual to all those adjustments under the VID-AD heading, particularly in view of the fact that the VID-GAIN adjustments are very useful in setting colour temperature. I used to use a CC15Y filter which didn't require any adjustments. I then found I could mimic the effect of the CC15Y filter by reducing BLUE in VID-GAIN. I now find I can use a stronger CC30Y filter by increasing BLUE in VID-GAIN from the original 59 to 80. The effect is to entirely remove the blue/purple in the shadows whilst simultaneously bringing the temperature down to around 6500. I'm pleased with this result. I'm not sure what further improvements I can make. Tycoondog2's settings for the CC40G filter don't work for me. I prefer the CC30Y.
 

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Discussion Starter · #3 ·
barryz,

Yup the whole thing is very confusing... I wonder if anyone could follow it?


Did you ever try adjusting the black-ref? I bought a photo cell at Radio Shack and put the R, G, B AVIA filters in front of it. I noticed that I could reduce the black level somewhat (this approach is suggested in the SMART procedure).


I also tried to use a cheap PC camera as the light meter. Would work great with suitable software that could analyze the intensity real-time during videocapture (simult measure R, G & B !). Haven't found any good software yet though... Also do not know about camera gamma tracking. May try to calibrate it using some ND filters.


I am not surprised that you had better results with a CC30Y rather than a CC40G. I have seen a couple of projectors now, and the black varies between blue and purple (you can actually change it somewhat by changing the black ref values).


If I can get some ND filters, I will try to calibrate my photo cell (and camera?) and measure the contrast ratio. I have a feeling it will be pretty poor.......
 

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Discussion Starter · #4 ·
barryz,


I just tried to change video gain and video cutoff (video gain I may understand, but what is video cutoff?).


In any case, I could not change either in RGB mode, but it worked in SVIDEO mode. I wonder why? That makes it difficult [for me] to use my computer DVD player and modify the video gain.....
 

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The English translation of the manual appears to be riddled with errors.


I'm currently in a different section of the manual, but the errors are just as clear:

Quote:
When the command sent by the projector cannot be understood,the error command ‘15H ’is returned by the computer.
Neat trick! When the projector doesn't understand something, a COMPUTER returns an error code.


Anyway, don't try to take the manual too literally. I have a feeling that the Japanese translation is the reason for a lot of the issues. I saw this before with the JVC manuals, and realize that they are not reference documents, but rather "suggestions" for what you can do. The only truth is the trial-and-error.


No, you can't adjust luminance when in SLIDE SHOW mode.

Yes, "Default" gamma should be "Normal".

Yes, the "projector" is sometimes accidentally called the "computer".


There is a lot of that in this manual.


Sorry that this post wasn't more help. I just wanted to let you know that you are not suffering along :D.
 

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rbrande,

That's right. Video cutoff and video gain cannot be adjusted in RGB mode - nor DVI mode which is what I hope to use when my HTPC is built. Drat it! I'm not sure also what video cutoff does, or HD gain which can be adjusted in RGB mode. I think eventually the solutions will come from computer software rather than filters in front of the lens.
 

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if the HD settings adjust the rgb input, isnt that the answer to the problem of adjusting RGB settings
 

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Good! I'll try that next time I decide to play with the settings instead of watching a movie. I wondered why you never gave us VID-GAIN or HD-GAIN before and after settings with your green filter. I take it you did make adjustments there?
 

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Discussion Starter · #9 ·
If we apply a filter, e.g. CCY30, it would be necessary to increase blue level (gain) to compensate.


What would the advantage be of adjusting the (vid-) gain and/or (vid-) cutoff in the set-up menu vs. simply increasing blue level in the regular menu?


Now, assuming that the projector is already adjusted for maximum contrast (no white saturation), wouldn't blue level start to saturate when its level is increased? This would cause lower (blue) contrast and a color shifts at high IREs...


Of course, if blue is far from saturating, this may not be the case. Does anyone know about the spectra of the Hitachi bulb? Is the blue intensity higher than the green?
 

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rbrande,

I'm afraid I haven't been very scientific in my approach to these service menu settings so far. I feel the need for a really detailed colour chart reference beyond what VE provides. I also need to sit down and make notes of my observations. I seem to have spent a lot of time gluing strips of cardboard and cutting out holes to make filter holders. From memory, increasing the blue in the users' menu seems to have a broader effect which upsets the colour balance elsewhere. A bit yukky in fact.


Whilst a yellow filter will predominantly reduce blue, the effect will spill over to the green part of the spectrum. There's no green adjustment so that means perhaps reducing the red vid-gain a small amount.


Best of luck! and let me know what you discover.
 

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I've not yet messed with my 5500, but I've seen some blue in the "black" screen. Otherwise, I like the colors. I understand from reading this forum that the blue is a constant level leakage in the lens/prism system. If that's the case, why not use a ND filter to knock down the leaking blue? The ND filter will also knock down RG too, but there's none there. When there's a picture with color, the ND will knock down all three leaving your calibration correct. I may not have done a good job of explaining, but the only reason I can see to filter a particular color and then recalibrating is that it may affect brightness less than an equivalent ND filter.


Am I wrong?


Chuck Davis
 

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Chuck,

I haven't tried an ND filter but my understanding is such a filter would reduce everything equally. Let's say you were to use an ND filter equal to one f/stop on a camera. That would effectively convert your 1500 ANSI lumen projector to a 750 ANSI lumen projector. Is that what you want? The unwanted blue in the shadows or the bars top and bottom would also be reduced by half but it would still be there. The idea of the filter is to kill the excess blue in the light leakage and raise the blue in the picture to compensate. Raising the blue in the picture does not raise the blue in the light leakage. Leakage is leakage.
 

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barryz - I guess I have a misunderstanding of filters in general. I've always thought of them as filtering out a certain amount of light, while you're saying that they filter out a percentage of light regardless of intensity. My thinking was that if a filter could reduce 1500 lumens to 1400, it would reduce 100 to zero. What you're saying is that, in that case, it would reduce 100 to 93. But, wouldn't that same thing apply to the blue that you're killing? Applying your one f/stop to blue only would reduce your blue component of white down to 750 lumens, reducing the leakage by one half, the same as a ND filter. To compensate for that, you'd have to turn down red and green to match the blue reduction. Why is a blue filter not just like a ND filter except it lets through green and red?


I'm not challenging you, and I'm definitely not an expert. I'm just trying to understand.


Chuck
 

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I have written several thing to help people under stand how CC or Colored filters and ND filters can be used. You might want check this earlier thread:

http://www.avsforum.com/avs-vb/showt...hreadid=124647


or

http://www.smartavtweaks.com/CCfilters.html


for a discussion of how CC filters can be used with coresponding changes in color levels to potentially improve contrast ratios and black levels.


Steve


p.s I am currently working with rbrande to see if SMART and/or filter can help the 5500.
 

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Discussion Starter · #15 ·
ChuckD,


You are absolutely correct. A filter would decrease the light intensity with a certain amount in a manner that depends on wavelength. A ND filter also reduces the light intensity with a fixed amount, but (ideally) independent of wavelength.


The idea of using a filter rather than a ND filter is that the total light loss would be less (only unwanted light intensity is reduced).


You are also correct in that after applying a filter (e.g. yellow to reduce blue), blue intensity has to be increased or red and blue decreased in order to maintain color balance. Unless there is a lot of "reserve" in blue (i.e. increasing blue does not saturate), reducing red and green will cause reduced contrast ratio.
 

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Steve, I would certainly be interested in the results that you come up with Rolf using the SMART.


On our 5500, I've gone into the SUB CONTRAST and SUB BRIGHT and knocked down the blue by around -12 and the green about -10 while increasing the red about +4. This, in conjunction with tweeks in the regular user menu, seems to have made strawberries and tomatos loose their blue blush and made colors far more natural. I also punch up the red a little and down the blue and green in the grey scale a bit and this seems to have helped, though the sky may be a little greyer. If the green is not reduced with the blue, I find that the yellow becomes more promenent. I am convinced that with proper tweeking, a color filter may not provide much (any?) improvement over careful calibration. Only need about umpteen hundred hours (or proper equipment) to get it right.
 

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toddalin,

I think you're right as regards making colours more accurate, for example the hue of strawberries and tomatos. But what about the blue light leakage that sometimes permeates a certain level of shadow in the picture, particularly in S-video mode. This blue appears to be impervious to any adjustment in either the user or service menus. I can't think of any remedy other than a colour specific filter.
 
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