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  #1  
Old 01-03-2016, 09:18 PM
Outland Outland is offline
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Proper Calibration

Hey all,

My Panasonic CRT's default picture settings are pretty awful. The picture is dark, contrasty (picture is turned all the way up), and the colors are almost bleeding.

I turned up the brightness, turned down the picture and color and now have a pretty good picture. I'm having trouble setting the color though. Either it's too cold, or too vivid.

What's the best way to get a reference picture?
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  #2  
Old 01-03-2016, 10:06 PM
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Too cold vs. too vivid is an interesting description - maybe I don't understand what you mean, but try this:

Turn the color all the way down. Is the picture reasonably neutral, or does it have a blue (or some other) tint? If it's not neutral, you need to adjust the cutoff (screen, or G2) controls. If the whole picture has some odd tint to it with the color off, it will be very hard to set a satisfactory color level.
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Old 01-03-2016, 10:15 PM
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No tint, the picture becomes black and white.

If I put color at 100% the picture becomes far too saturated and bright reds start to lose detail and bleed, probably due to the tube's age.
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Old 01-04-2016, 10:29 AM
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What do you mean by "100%?" Is that just cranking the color knob to max? That obviously should be too much. If you cannot judge the setting by the look of skin tones, then there are more technical ways involving color bars while viewing through a blue filter. For that you will need a DVD with color bar pattern and a blue optical filter.

You say the CRT may be weak. Does the red gun bleed when you turn the color all the way down but turn the contrast to max? If it does, you have to reduce the contrast to eliminate the bleeding, and reduce it a bit more to allow for bright reds. If a black and white picture doesn't bleed at max contrast, the CRT is probably good enough, you just have to avoid overdriving by using somewhat less contrast and the right amount of color.

Because of the color difference gains used in NTSC sets to compensate for modern phosphors and get proper skin tones, the red is driven the hardest of all saturated colors (and also possibly harder than blue or green to get grayscale tracking), so red is usually the first color to show bleeding problems.
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Old 01-04-2016, 12:06 PM
Outland Outland is offline
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Quote:
Originally Posted by old_tv_nut View Post
What do you mean by "100%?" Is that just cranking the color knob to max? That obviously should be too much. If you cannot judge the setting by the look of skin tones, then there are more technical ways involving color bars while viewing through a blue filter. For that you will need a DVD with color bar pattern and a blue optical filter.
Yes, that's what I meant. Where can I find these color bars and blue filter?

Quote:
You say the CRT may be weak. Does the red gun bleed when you turn the color all the way down but turn the contrast to max? If it does, you have to reduce the contrast to eliminate the bleeding, and reduce it a bit more to allow for bright reds. If a black and white picture doesn't bleed at max contrast, the CRT is probably good enough, you just have to avoid overdriving by using somewhat less contrast and the right amount of color.
With color all the way down and picture all the way up, nothing bleeds. It's just a very contrasty black and white picture.

What I keep running into is a hazy black from brightness being too high, or details in the blacks being lost because brightness is too low. Similarly, too much color loses details, and too little looks dull.

I guessed the tube is worn because the default settings are simply far too dark (on other TVs the default settings are usually too bright). The default settings being everything at halfway, except picture which is at 100%. There's plenty of headroom with the brightness control though.

Quote:
Because of the color difference gains used in NTSC sets to compensate for modern phosphors and get proper skin tones, the red is driven the hardest of all saturated colors (and also possibly harder than blue or green to get grayscale tracking), so red is usually the first color to show bleeding problems.
I see. In my case, the red gun does bleed slightly with color all the way up and details are lost within.
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Old 01-04-2016, 02:26 PM
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What is the year of manufacture of your set? Tube or solid state? Before a certain point in time (certainly all tube sets), sets had less than 100% DC coupling, which means that on bright scenes, the lowlights would get too dark (blacker than black), and on dark scenes they would get too light (grayish). If it's one of these earlier designs, you are stuck with it.

Regarding the test DVD, it appears they are no longer made, although some (like Digital Video Essentials) are made in Blu-Ray form for HD sets. Warning: although these disks contain the test patterns needed, they generally are poorly explained in terms of how to use the patterns, and also some of them have terrible menu interfaces, as attested by many user reviews.

This page for one brand of test disk shows how to use the blue filter:
http://handforgedvideo.com/portfolio...olor-and-tint/

The idea is to get zero blue on bars that shouldn't contain blue (red, yellow, green), while getting the same amount of blue on bars that do contain blue (blue, magenta, cyan). But really, if your black and white picture is OK, you should be able to get the same result by adjusting for good skin tones.

If your problem is that the color changes when the scene changes, then no amount of calibration will fix it.
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  #7  
Old 01-04-2016, 02:48 PM
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You could also torrent download a copy of a good test pattern DVD (like Avia Guide to home theater) and burn it to disc.

The blue filter could be obtained from high end camera shops, places that do stage lighting, the internet, destroying a CBS field sequential set (I'm joking), etc.
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Old 01-04-2016, 05:27 PM
Damnation Damnation is offline
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Quote:
Originally Posted by old_tv_nut View Post
Regarding the test DVD, it appears they are no longer made, although some (like Digital Video Essentials) are made in Blu-Ray form for HD sets. Warning: although these disks contain the test patterns needed, they generally are poorly explained in terms of how to use the patterns, and also some of them have terrible menu interfaces, as attested by many user reviews.
I've found Avia's Guide to Home Theater calibration DVD to be better than DVE (despite DVE having an updated Blu-ray version). Avia seems more CRT-centric, like all the video tutorials accompanying the test patterns explain how to use them using a CRT, very little about flat panels. If you find a complete Avia DVD it'll include a blue filter inside the case along with a booklet.

I have two "newer" Panasonics, from '97 and '01 (GAOO Superflat), color looks best on both set fairly low, around 18-20 out of 100 in the user menu. Any higher and the picture quickly looks like a radiating eyesore.

Last edited by Damnation; 01-04-2016 at 05:40 PM.
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  #9  
Old 01-04-2016, 07:33 PM
Outland Outland is offline
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Quote:
Originally Posted by old_tv_nut View Post
What is the year of manufacture of your set? Tube or solid state? Before a certain point in time (certainly all tube sets), sets had less than 100% DC coupling, which means that on bright scenes, the lowlights would get too dark (blacker than black), and on dark scenes they would get too light (grayish). If it's one of these earlier designs, you are stuck with it.
June 1994. It's obviously all solid state, model CT-20S2S. Here's a photo of the set from someone. Nothing special.

An interesting observation I had was turning brightness all the way down caused the menu text to streak right. Turning it up eliminates that.

Great info about the blue filter. I'll buy a used DVD of Avia with the filter because I can't get this color right. I think the TV might just display colors a little warm or red-heavy.

18-20 on my set is almost black and white. >40 is radiation level topping out at 63, so I'm trying 30s now. What I think is happening is the blues and yellows are great, but the reds are too bright. A plaid red shirt is a good example, it loses fine details. Greens are pretty aggressive too.

Certainly nothing like the precise cool colors of a Trinitron.

I'll take some pictures so you all can see what I mean.
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  #10  
Old 01-04-2016, 08:18 PM
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With what you describe I'd turn up the colors till just before smearing of any color occurs, or perhaps the minimum saturation necessary to yield an acceptable picture, and maybe try adjusting the hue/tint control.

It is possible the jug is at the end of the road. If the CRT is used up I'd just grab a decent similar set to replace it off the free section of craigslist and be done with it.

IMHO too many VK'ers have been wasting too much energy on too much worthless BPC era SS crap that is not worth almost any repair effort once it dies.
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  #11  
Old 01-04-2016, 08:27 PM
Outland Outland is offline
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Quote:
IMHO too many VK'ers have been wasting too much energy on too much worthless BPC era SS crap that is not worth almost any repair effort once it dies.
Very true. It's more of a curiosity experiment.

What are the signs of a used up CRT? I was under the impression the tube is ok if there's no tint with color turned all the way down. What exactly happens when a CRT starts to fail?

I've also brought this set back from vertical compressing death, so what the heck.
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Old 01-04-2016, 09:37 PM
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Signs of a bad CRT include but are not limited to (or always caused by the CRT): Dim picture, shift in gray scale tracking, video smear (especially if associated with only a single primary color), and poor focus. Different tubes fail differently, and manifest different combos of symptoms. The best test is a CRT tester and a working set that uses the tube....Some tubes test weak-bad but have decent life left at reduced brightness, others test mediocre to bad but preform lousy in an actual TV (60's-70's small low voltage focus tubes are notorious for having mediocre to bad focus once the emission drops below like-new status, and 50's monochrome tubes tend to let you milk a good picture out of them with a brightener until the cathode is totally gone).
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Old 01-05-2016, 08:14 AM
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Look to the 200V filter cap, a $2 gamble.
Symptoms are any one or more of the following:
Too bright.
Streaking.
Darker on left than right.
Jailbars. ( vert dark bars)
Poor all around pix.
Can look like soft CRT.

Also it may be the CRT is a little weak. Screen shots of real programing
helps there. There may be a cheat to get more life.

Someone may have a manual & can tell you the "C" number.
If not take chassis pixs (nudies) & it can be traced down easily.
This is a VERY common problem across all brands.

73 Zeno
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Old 01-05-2016, 10:18 PM
Outland Outland is offline
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I took some photos of what I mean.

I used a DVD of Frasier, a show with pretty modest colors. Here they look pretty good. This DVD player for some reason has a higher black level than true black (confirmed on other TVs) but everything else looks good.





Here is where the problem is. The red shirt is too red.



The same scene with color at 0. There isn't a green tint in real life. You can see details in the shirt that you can't see with color.



If these photos are bad, I'll take some better ones. My phone doesn't have the best camera.

The picture is not dim, and is quite sharp. The smearing goes away with color down. My conclusion is that the tube has some life left, I just need to find the right color level. No jailbars, softness, one side brighter than other etc.
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Old 01-06-2016, 10:13 AM
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Bright areas seem washed out. The sky & his forehead & hair.
Also if the shirt is RED it looks orangy/brown. Otherwise it
looks pretty darn good.
I will say CRT just a little weak.
If you open it there is a cheat/ test but it comes with RISK.

73 Zeno
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