Jump to content



Sign up for a free account to remove the pop-up ads

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests and remove the pop-up ads that guests get. Click here to create your free account.

Photo
- - - - -

Color Problem - TV or poorly mastered DVD's?


This topic has been archived. This means that you cannot reply to this topic.
6 replies to this topic

#1 of 7 OFFLINE   Sam R. Aucoin

Sam R. Aucoin

    Stunt Coordinator



  • 212 posts
  • Join Date: Jul 05 1999

Posted June 02 2004 - 11:45 AM

I have a Hitachi 42HDT50 plasma with the following components attached:

VOOM receiver upconverting to 1080i
Hughes HD-HTL receiver upconverting to 1080i
Denon 5900 DVD player upconverting to 720p

After an ISF calibration (which I am very pleased with - this is not a complaint with the calibrator), and numerous attempts at calibration using the original DVE, DVE Digital, and AVIA, I cannot, for the life of me, eliminate what appears to be a somewhat "green tint" in the background of the picture.

It is evident when someone has blonde hair (the hair looks blonde with green highlights), it really shows up in black and white movies (most recently, The Snake Pit from Fox Studio Classics), and appears in the wave-action in Master and Commander.

This is really driving me crazy when I watch TV, and I would appreciate any help/suggestions you might have to eliminate what I would call "green push".

Note: I can eliminate it by turning down the green in my color decoder, but then my set is no longer properly calibrated for color.

Note 2: My Hitachi has quite a bit of control over color control. I have one set of controls called a "Color Decoder" that allows me to control Red, Green, and Tint. I have a completely different set of controls called "Color Management" that allows me to control (independent of the Color Decoder) Red, Green, Blue, Cyan, Magenta, and Yellow.

So, I have quite a number of controls to use to try to fix the problem. The "problem" is that I don't know how to go about fixing it, when the color bars of the various calibration discs indicate that my set is properly calibrated, and then I see this green tint in movies.

Thanks in advance,

Sam
Sam R. Aucoin

#2 of 7 OFFLINE   WesleyHester

WesleyHester

    Stunt Coordinator



  • 144 posts
  • Join Date: Feb 14 2002
  • Real Name:John Hester
  • LocationSelma, AL

Posted June 02 2004 - 12:25 PM

I really wish I could help you because I had a similar problem 2 years ago. Unfortunately, I have a CRT-based rear projection set and have never owned a plasma display.
My problem ended up being that the red "gun" was set slightly too high causing the "green" gun to over compensate, i.e. flicker from high to low intensity thus causing problems with all colors.

#3 of 7 OFFLINE   Drew_W

Drew_W

    Screenwriter



  • 1,718 posts
  • Join Date: Jul 02 2003

Posted June 03 2004 - 04:22 AM

Could it be a defect in the plasma display?
I gave up on tracking my collection and actually started watching what I have.

#4 of 7 OFFLINE   Allan Jayne

Allan Jayne

    Screenwriter



  • 2,406 posts
  • Join Date: Nov 01 1998

Posted June 03 2004 - 04:52 AM

You may have gray scale tracking problems. For example light parts of the scene (or lighter scenes) may appear correct whild dark parts of ehe scene (or darker scenes) may apper greenish.

It is trial and error as to whether adjusting color using your Color Decoder controls results in better gray scale tracking compared with using your Color Management controls.

In addition different TV stations may have a different calibration compares with your DVD player, forcing you to recalibrate the TV each time or live with the difference. I am thinking that you would want to first use Color Management to set the color for DVD (component video) and then use Color Decoder to set the color for broadcasts. For the second step connect the DVD player with AVIA disk using an S-video connection for those few minutes.

Video hints:
http://members.aol.c...ynejr/video.htm
.

#5 of 7 OFFLINE   Sam R. Aucoin

Sam R. Aucoin

    Stunt Coordinator



  • 212 posts
  • Join Date: Jul 05 1999

Posted June 03 2004 - 12:33 PM

Allan:

I forgot to mention that I have all of my components connected to my plasma via a 4x1 DVI switcher.

Question: I don't understand what you mean by calibrating color with one type of input (component) and then performing additional calibration using another type of input (S-Video).

Now that you know I have DVI running to the monitor, AND the fact that I have had the plasma ISF calibrated (with the test results sitting in front of me indicating that my TV's grayscale tracking is almost dead-on perfect), would you mind "walking me through" what you suggest is a way to fix this?

Thanks in advance,

Sam
Sam R. Aucoin

#6 of 7 OFFLINE   Eric Stewart

Eric Stewart

    Stunt Coordinator



  • 76 posts
  • Join Date: Oct 31 2002

Posted June 16 2004 - 03:14 AM

Sam,

I have a new Hitachi 32HDT50 plasma. It hasn't been ISF calibrated. I feed it a YPbPr signal from my Bose LifeStyle 18's internal DVD player. I would call the picture excellent, overall, but I've noticed some things I cannot explain. These things may help shed some light on your problem.

First of all, my settings: I am using Medium Color Temperature, though which Color Temp setting I choose makes little difference to the anomalies I am about to list. Also, I do not have Color Management: Set User Colors turned on. Red and Green under Color Decoding are at default 50%. Auto Color is Off (actually, not applicable to YPbPr). Under Setup, Set The Color System is set to Auto, which for this input equates to SDTV/DVD as opposed to HDTV.

(1) When I use Avia or Video Essentials to adjust Color and Tint, the results seem to me to be way off. Using either the included blue filter or the set's ability (under Color Decoding) to turn off red and green and just show blue, I can get the patches in the appropriate color-bar patterns to look "just right" -- i.e., indistinguishable from one another -- but when I switch back to ordinary video material, I find Color saturation is too high and flesh tones (as adjusted by the Tint control) are skewed way over toward rose red and not nearly yellow (or green) enough to suit me. These discrepancies from what my eye "prefers" are not tiny ones; they are quite large, especially in the case of Tint. I find I prefer to lower Color from around 45% to 28%-35%, and I prefer to move the Tint slider from slightly left of center (redder) to considerably right of center (greener). (I can't for the life of me explain why these color test patterns "don't work" with this TV, as they work fine with a Samsung HLN617W DLP-based set I have and also with the various CRT-based sets I have had.)

(2) I find that the setting of the Color control has an inexplicable effect on the "tinge" of black and white material. Try this: first, set Color Temperature to High -- it makes the following easier to see. Next, cue up a B&W DVD or find some B&W material on a color DVD. Hit pause. Now manipulate the TV's Color control. If you turn it all the way down to 0%, you should get a noticeably green tint to the B&W picture. Raising the Color control from 0% to 1%, you should see a less pronounced green tint. That greenish tinge verges into a reddish rose as the Color control is raised to and then beyond its "normal" setting. The gray scale will probably be at its most neutral at about the Color setting that looks best with full-color material.

(3) Point (2) notwithstanding, I find that B&W material on DVD is all over the map with respect to the tinge, if any, with which it is displayed. I have recently been watching James Bond DVDs with their making-of documentaries. There are in these documentaries all sorts of B&W portions -- monochrome footage, still photos, etc. As one B&W image succeeds another, the tinge of the grayscale is apt to change crazily from neutral to greenish to reddish, etc.

(4) When I watch 4:3 material in proper aspect ratio with "gray" bars on the sides, the "gray" bars have a greenish tinge which can be noticeably different than the tinge (if any) of B&W material shown between the bars.

All these observations lead me to believe that color on the Hitachi plasmas is a much more complex beast than do-it-yourself or even ISF calibrations can deal with fully.

I would urge you to call your ISF calibrator back in and point out the anomalies you complain of -- not in an accusing way, but seeking his further cooperation. (I assume this would be at no cost to you, assuming he guarantees your satisfaction.) Maybe he can shed further light on why a set which has nominally been "ISF calibrated" still has such anomalies.

Also, to answer the question you asked earlier, calibration (ISF or otherwise) is done by changing (usually, numerical) parameters in the set's ordinarily inaccessible "service menu." Typically (I know this is true of my Samsung DLP and suspect it is true of my Hitachi plasma) the sets of parameters have different values for different types of video input such as DVI, YPbPr, S-Video, etc. The parameters can also be different in value for, for example, 480i vs. 480p format input via YPbPr (a.k.a. component video). The ISF calibrator typically calibrates only those inputs and video formats you actually use (in your case DVI), since each input/format will have a different optimal calibration.

In other words, each input/format is a special case, and none more so than DVI. With DVI the amount of color "decoding" the set does is supposedly nominal or minimal, and it is mainly up to the source device (the DVD player, etc.) to get colors right. That seems in fact to be the case with my Samsung DLP, which I feed with a DVI-equipped Samsung DVD player. I have not tried DVI with the Hitachi plasma, so I don't know if it is also true with the Hitachi. As an example, with the Samsung I cannot adjust Tint with a DVI input, though I can adjust Color.

So one possibility for you is to hook up a YPbPr (or component video) connection from DVD player to TV -- leaving the DVI connection as is -- and see whether the anomalies you complain of affect YPbPr. They very well may not. You may then decide you want to have the YPbPr ISF-calibrated (for extra money).
Eric Stewart
Catonsville, MD

#7 of 7 OFFLINE   Eric Stewart

Eric Stewart

    Stunt Coordinator



  • 76 posts
  • Join Date: Oct 31 2002

Posted June 16 2004 - 03:14 AM

Sam,

I have a new Hitachi 32HDT50 plasma. It hasn't been ISF calibrated. I feed it a YPbPr signal from my Bose LifeStyle 18's internal DVD player. I would call the picture excellent, overall, but I've noticed some things I cannot explain. These things may help shed some light on your problem.

First of all, my settings: I am using Medium Color Temperature, though which Color Temp setting I choose makes little difference to the anomalies I am about to list. Also, I do not have Color Management: Set User Colors turned on. Red and Green under Color Decoding are at default 50%. Auto Color is Off (actually, not applicable to YPbPr). Under Setup, Set The Color System is set to Auto, which for this input equates to SDTV/DVD as opposed to HDTV.

(1) When I use Avia or Video Essentials to adjust Color and Tint, the results seem to me to be way off. Using either the included blue filter or the set's ability (under Color Decoding) to turn off red and green and just show blue, I can get the patches in the appropriate color-bar patterns to look "just right" -- i.e., indistinguishable from one another -- but when I switch back to ordinary video material, I find Color saturation is too high and flesh tones (as adjusted by the Tint control) are skewed way over toward rose red and not nearly yellow (or green) enough to suit me. These discrepancies from what my eye "prefers" are not tiny ones; they are quite large, especially in the case of Tint. I find I prefer to lower Color from around 45% to 28%-35%, and I prefer to move the Tint slider from slightly left of center (redder) to considerably right of center (greener). (I can't for the life of me explain why these color test patterns "don't work" with this TV, as they work fine with a Samsung HLN617W DLP-based set I have and also with the various CRT-based sets I have had.)

(2) I find that the setting of the Color control has an inexplicable effect on the "tinge" of black and white material. Try this: first, set Color Temperature to High -- it makes the following easier to see. Next, cue up a B&W DVD or find some B&W material on a color DVD. Hit pause. Now manipulate the TV's Color control. If you turn it all the way down to 0%, you should get a noticeably green tint to the B&W picture. Raising the Color control from 0% to 1%, you should see a less pronounced green tint. That greenish tinge verges into a reddish rose as the Color control is raised to and then beyond its "normal" setting. The gray scale will probably be at its most neutral at about the Color setting that looks best with full-color material.

(3) Point (2) notwithstanding, I find that B&W material on DVD is all over the map with respect to the tinge, if any, with which it is displayed. I have recently been watching James Bond DVDs with their making-of documentaries. There are in these documentaries all sorts of B&W portions -- monochrome footage, still photos, etc. As one B&W image succeeds another, the tinge of the grayscale is apt to change crazily from neutral to greenish to reddish, etc.

(4) When I watch 4:3 material in proper aspect ratio with "gray" bars on the sides, the "gray" bars have a greenish tinge which can be noticeably different than the tinge (if any) of B&W material shown between the bars.

All these observations lead me to believe that color on the Hitachi plasmas is a much more complex beast than do-it-yourself or even ISF calibrations can deal with fully.

I would urge you to call your ISF calibrator back in and point out the anomalies you complain of -- not in an accusing way, but seeking his further cooperation. (I assume this would be at no cost to you, assuming he guarantees your satisfaction.) Maybe he can shed further light on why a set which has nominally been "ISF calibrated" still has such anomalies.

Also, to answer the question you asked earlier, calibration (ISF or otherwise) is done by changing (usually, numerical) parameters in the set's ordinarily inaccessible "service menu." Typically (I know this is true of my Samsung DLP and suspect it is true of my Hitachi plasma) the sets of parameters have different values for different types of video input such as DVI, YPbPr, S-Video, etc. The parameters can also be different in value for, for example, 480i vs. 480p format input via YPbPr (a.k.a. component video). The ISF calibrator typically calibrates only those inputs and video formats you actually use (in your case DVI), since each input/format will have a different optimal calibration.

In other words, each input/format is a special case, and none more so than DVI. With DVI the amount of color "decoding" the set does is supposedly nominal or minimal, and it is mainly up to the source device (the DVD player, etc.) to get colors right. That seems in fact to be the case with my Samsung DLP, which I feed with a DVI-equipped Samsung DVD player. I have not tried DVI with the Hitachi plasma, so I don't know if it is also true with the Hitachi. As an example, with the Samsung I cannot adjust Tint with a DVI input, though I can adjust Color.

So one possibility for you is to hook up a YPbPr (or component video) connection from DVD player to TV -- leaving the DVI connection as is -- and see whether the anomalies you complain of affect YPbPr. They very well may not. You may then decide you want to have the YPbPr ISF-calibrated (for extra money).
Eric Stewart
Catonsville, MD