View Full Version : Proper Calibration


Outland
01-03-2016, 10:18 PM
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?

old_tv_nut
01-03-2016, 11:06 PM
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.

Outland
01-03-2016, 11:15 PM
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.

old_tv_nut
01-04-2016, 11:29 AM
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.

Outland
01-04-2016, 01:06 PM
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?

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.

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.

old_tv_nut
01-04-2016, 03:26 PM
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/setting-color-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.

Electronic M
01-04-2016, 03:48 PM
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.

Damnation
01-04-2016, 06:27 PM
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.

Outland
01-04-2016, 08:33 PM
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. (https://www.flickr.com/photos/15656236@N00/5405565492) 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.

Electronic M
01-04-2016, 09:18 PM
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.

Outland
01-04-2016, 09:27 PM
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.

Electronic M
01-04-2016, 10:37 PM
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).

zeno
01-05-2016, 09:14 AM
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:smoke:

Outland
01-05-2016, 11:18 PM
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.

http://i1052.photobucket.com/albums/s451/apples555/IMG_0612_zpsk4pww5fv.jpg

http://i1052.photobucket.com/albums/s451/apples555/IMG_0618_zpsbm5jmmd8.jpg

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

http://i1052.photobucket.com/albums/s451/apples555/IMG_0624_zpsavtb7nvq.jpg

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.

http://i1052.photobucket.com/albums/s451/apples555/IMG_0625_zpsz9gdf1tm.jpg

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.

zeno
01-06-2016, 11:13 AM
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:smoke:

Outland
01-06-2016, 02:52 PM
What is the cheat?

The washout is the camera's fault, his hair is quite detailed in real life. The problem with the red does come across in the photos though. I turned down the color again so it doesn't obscure details, but now the scene looks a little dull again.

I don't understand why the factory preset is so dark.

Until a few years ago, my friend's family had a huge 1988 Mitsubishi Diamond Vision II 3503. Towards the end, it was so dark you could barely see the outline of colors on a screen that almost looked off. At one point, I looked in the settings to find that brightness was already turned all the way up.

Why does this happen? Is deterioration accelerated by certain picture settings? I've heard contrast is the biggest decider. Yet on my set, it appears picture has plenty of headroom, it's brightness that's in shortest supply.

wa2ise
01-06-2016, 03:37 PM
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.

That's similar to turning up a radio's volume control all the way up, you get distortion.

Damnation
01-06-2016, 05:35 PM
What DVD player are you using? The player might suffer from chroma upsampling error, an MPEG decoder error that plagued many early DVD players and is still evident in cheap players. It's most evident in red, causing horizontal streaking/blur in the picture's resulting color. Some affected players really exhibit it worse than others.

Outland
01-06-2016, 08:14 PM
An old Sony DVP-S7000, which appears to be exempt from the bug.

Outland
01-07-2016, 05:46 PM
I got a great picture after a lot of tinkering. Here are the settings:

Color: 31/63
Tint: Center
Brightness: 51/63
Picture: 40/63
Sharpness: Center

Bright reds still smear a little, but I can't be sure that's not from the RF signal.

Factory is:

Color: 31/63
Tint: Center
Brightness: 31/63
Picture: 63/63
Sharpness: Center

Are these settings good?

Electronic M
01-07-2016, 06:49 PM
Are these settings good?

Only if they look good to you.

TV settings can be somewhat subjective. (Some color blind and some elderly folks prefer settings that 95% of the rest of the population would consider to be crap....And some sets like tube era GE sets don't like to let you set them any better, than slightly "off")

Outland
01-07-2016, 08:21 PM
Good enough for me. Thanks for the tips all.

Outland
06-02-2016, 09:02 PM
I've gotten most of the settings almost perfect for a dark room. Picture is set at 50%, which is reasonable and not excessive from what I understand.

I'm still having trouble with brightness/black level. I've run into the situation that from a true black signal (no picture content), setting brightness to produce perfect black (no light emitted) swallows dark blacks when there is picture content. Likewise, adjusting black to produce no light when there is content on the screen (such as the picture control menu box) ends up making true black (nothing on screen) a dark gray. I've settled on an in-between setting by going one tick below no light output on the picture content setting. True black is still gray, but only noticeable in a dark room and even then it's very slight.

These are very small changes, but it's definitely changing. Why is black level changing?

Also, the top right corner of the picture is slightly dimmer than the other corners. Not sure why that is.

Eric H
06-02-2016, 09:26 PM
Most average CRT sets of that era weren't capable of a perfect (or even halfway decent) picture even when new.
If you want perfect, or at least something with good black levels and accurate color reproduction, then you need to find one of the higher end sets like a Sony XBR or an RCA Dimensia, Panasonic Tau, or even an older Sony Professional Monitor, they can be had for cheap now.

old_tv_nut
06-02-2016, 09:29 PM
1) DC restoration may not be perfect in this chassis - if not, you just have to live with it.
2) The black setup level in the source may be slightly off - do you get the same effect for all sources?
3) Are you sure it's changing? Adjusting to make black details visible on a bright picture in a completely dark room can cause you to raise it slightly to compete with optical flare in your eyes. You should set it to be correct with average pictures and not worry about the no-content case, unless you are seeing it come up to an objectionable level when content contains a fade to black.

RCAZenith
06-03-2016, 08:46 AM
Most average CRT sets of that era weren't capable of a perfect (or even halfway decent) picture even when new.
If you want perfect, or at least something with good black levels and accurate color reproduction, then you need to find one of the higher end sets like a Sony XBR or an RCA Dimensia, Panasonic Tau, or even an older Sony Professional Monitor, they can be had for cheap now.



You know, I have heard people say the exact opposite. When properly set up and with a good CRT, the old sets can produce a picture on par with the later sets due to higher quality components. However, on a tired CRT none of that matters. A lot of it comes down to knowledge how to adjust your set. I remember black plastic crap sets never needed adjusting - save for portable B&W sets. The average person who owns a flat screen or BPC CRT set won't be able to tune the settings right on a knob tuned set (manual controls, etc).


Sent from my iPhone using Tapatalk

Outland
06-03-2016, 12:31 PM
1) DC restoration may not be perfect in this chassis - if not, you just have to live with it.
2) The black setup level in the source may be slightly off - do you get the same effect for all sources?
3) Are you sure it's changing? Adjusting to make black details visible on a bright picture in a completely dark room can cause you to raise it slightly to compete with optical flare in your eyes. You should set it to be correct with average pictures and not worry about the no-content case, unless you are seeing it come up to an objectionable level when content contains a fade to black.

1) That's ok if it is. The key is to get a good enough calibration that shows the picture as intended.
2) I have two calibrations, one for 7.5 IRE and one for 0 IRE, and the sources give solid black floors in those ranges.
3) When there's a fade to black, it is slightly gray in a dark room. If I calibrate purely by picture content (slightly brighter) then it's slightly more gray. The opposite is true if I calibrate by a completely black picture.

I suppose I should just calibrate by the picture and leave it be.

For whoever suggested getting a higher-end set, I've been on the hunt for an early '90s KV-20V50, KV-20EXR20, or KV-20V60 (20" XBRs essentially) for 4 years now. Not once has it popped up on CL, thrift, or anywhere else. Almost everything is late '90s to SPC era or bigger than 20". The only reason I have this Panasonic is that after it was replaced by an HDTV by my family, it was stored in the basement ever since and I just happened to come across it. I always liked it and couldn't go without it.

It really is a nice TV otherwise. I had a KV-20V80 from '99 and, for whatever reason, this Panasonic pulled a better and sharper picture from RF than the 20V80 did from composite of the same source. There was no dot crawl on the V80 admittedly, but the picture was awful and blurry. I attributed it to an early digital comb filter in the V80 that removed crawl way too aggressively.

Electronic M
06-03-2016, 01:34 PM
Get (or torrent :naughty:) an avia guide to home theater disc. It will have two thin moving slightly darker or lighter black bars in the black bar of the gray-scale setup, and instructions that will help you adjust the level correctly.