:"Washed out" picture, novice questions about saturation - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 8 Old 09-29-2012, 12:04 PM - Thread Starter
tkc
Member
 
tkc's Avatar
 
Join Date: Sep 2004
Posts: 163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Hi everyone, I've been working on a DIY calibration this week, and have a couple of questions. I'm hoping that someone with more experience can help me!

I have been calibrating a Panasonic 42G15 plasma, and have worked on its THX, Custom and Standard modes. The THX mode calibrates very nicely, but its max output is just under 25 fL, and it's too dim for a lot of my viewing. I get a nice grayscale with the other modes, but the average gamma for Custom (max output about 53 fL) is about 2.2, with a broad peak from about 40 IRE to 70 IRE at 2.4. The average gamma for Standard (max output over 70 fL!) looks like the Custom graph moved down .2, so its average is about 2.0, with a broad peak at 2.2.

I have also calibrated my Color control by setting red luminance to 21% of white, Brightness by working to not crush blacks, and Picture/Contrast just by eye (no clipping appears at any level). However, I find that images appear a bit washed-out (source is satellite HD, with no video adjustments on the HD box itself). I watch in a non-light-controlled living room, with blinds drawn but a reasonable amount of ambient light.

If I lower brightness (crushing blacks), images pop a fair bit more. I also find that increasing Picture also improves the picture to my eye. Boosting color also makes things change for the better, as long as I don't overdo it. Without these tweaks, I find it a little hard (eye strain) to watch the HD content. I suppose it could be the HD box -- I will have to check with Blu-ray content (Oppo BDP-83) to make sure.

One thing I've found while measuring my set is that modifying the grayscale, Color and Tint settings of my TV has changed the accuracy of my saturation sweeps for the worse. That is, when measuring primaries and secondaries at 25%, 50% and 75% saturation levels, I am farther outside the box than I was before calibration. (Of course, only the positions of the secondaries at 100% saturation have changed after calibrating).

If anyone has any helpful feedback for how to handle the issue with black level and color, I'd really appreciate it. Thanks!
tkc is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 09-29-2012, 12:28 PM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,586
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 165
Once you have brightness and contrast set correctly the other big factor in saturation (besides your acutal gamut) is gamma.

If you're gamma is too low, you'll get a bit of a washed out look, high gamma settings should increase saturation.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is online now  
post #3 of 8 Old 09-29-2012, 01:17 PM - Thread Starter
tkc
Member
 
tkc's Avatar
 
Join Date: Sep 2004
Posts: 163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
If you're gamma is too low, you'll get a bit of a washed out look, high gamma settings should increase saturation.

If this is the case, for a display that has a low, non-adjustable gamma value, is there a prescription for how to improve the image?
tkc is offline  
post #4 of 8 Old 09-29-2012, 01:42 PM
Member
 
forsureman's Avatar
 
Join Date: Sep 2012
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
My method;
Turn off dynamic brightness and contrast.
Using the calibration disk from the calibration forum, set the brightness and contrast in the screen where they're showing their flashing bars.
Then using blue filter glasses calibrate the saturation and hue.
Then go to the bar ramp showing r,g,b,m,c colors and turn up the rgb gain until the rgb bars are barely visibility separated, then calibrate the offset rgb somehow.

Then see if dynamic contrast, flesh tone helps.
forsureman is offline  
post #5 of 8 Old 09-29-2012, 01:44 PM
AVS Special Member
 
PlasmaPZ80U's Avatar
 
Join Date: Feb 2009
Posts: 7,057
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 187
Quote:
Originally Posted by sotti View Post

Once you have brightness and contrast set correctly the other big factor in saturation (besides your acutal gamut) is gamma.
If you're gamma is too low, you'll get a bit of a washed out look, high gamma settings should increase saturation.

do colors actually measure more saturated with a darker gamma or is this difference purely based on perception? what about black levels and color saturation?
PlasmaPZ80U is offline  
post #6 of 8 Old 09-29-2012, 02:42 PM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,586
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 165
Quote:
Originally Posted by PlasmaPZ80U View Post

do colors actually measure more saturated with a darker gamma or is this difference purely based on perception? what about black levels and color saturation?

Yes higher gammas increase measured saturation for colors in the middle of the gamut, but it doen't expand the gamut.

Black level will effect the entire gamut including the edge. Higher black levels (brighter) will decrease saturation creating a washed out look.

That's why getting black level right is a big deal and why also getting gamma correct is a huge part of getting an accurate calibration.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is online now  
post #7 of 8 Old 09-29-2012, 11:26 PM - Thread Starter
tkc
Member
 
tkc's Avatar
 
Join Date: Sep 2004
Posts: 163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Joel, does this mean that if saturation sweeps show the measurements of the less saturated colors (e.g. cyan at 25%, 50% saturation, etc.) are all undersaturated from their targets, that lowering the black level can improve this (at the cost of perhaps crushing black)?
tkc is offline  
post #8 of 8 Old 09-30-2012, 09:03 AM
AVS Special Member
 
sotti's Avatar
 
Join Date: Aug 2004
Location: Seattle, WA
Posts: 6,586
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 165
Quote:
Originally Posted by tkc View Post

Joel, does this mean that if saturation sweeps show the measurements of the less saturated colors (e.g. cyan at 25%, 50% saturation, etc.) are all undersaturated from their targets, that lowering the black level can improve this (at the cost of perhaps crushing black)?

It would, but I wouldn't consider it a worthwhile trade off.

Joel Barsotti
SpectraCal
CalMAN Lead Developer
sotti is online now  
Reply Display Calibration

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off