Increase gamma by lowering brightness - AVS Forum
Forum Jump: 
 
Thread Tools
Old 02-02-2013, 04:34 AM - Thread Starter
Senior Member
 
ndaa75's Avatar
 
Join Date: Dec 2011
Location: Caister on Sea, UK
Posts: 493
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 22
Just a general question really. Is it wise to usenthe brightness setting to increase gamma?
For example I have a Panasonic VT30. Using a pluge i have set the correct brightness level accordingly. However to calibrate to 2.28 which gives better image pop over 2.2 i have to lower the brightness setting by 5 clicks. The set itself has 10pt gamma settings but playing with these can lead to undesired screen artifacts. So the question is have i followed the correct process in which to increase gamma ?

Benq W1080ST Projector, Panasonic TXP55VT30 plasma, Yamaha RXA3020 AVR, Denon DVD-2500BT, Q Acoustics 1010i in 7.1, i1 Pro spectro, i1 Display Pro, Calman 5 Enthusiast, PS3, Xbox 360, Wii

Calibration Management Disc
ndaa75 is offline  
Sponsored Links
Advertisement
 
Old 02-02-2013, 04:48 AM
AVS Addicted Member
 
Bond 007's Avatar
 
Join Date: Jun 2012
Location: Cincinnati, OH
Posts: 12,451
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 418 Post(s)
Liked: 878
You would be better served by posting that here:

http://www.avsforum.com/t/1408338/official-panasonic-vt50-owners-thread/9840#post_22913104

No, Mr. Bond. I expect you to die!
Bond 007 is offline  
Old 02-02-2013, 05:54 AM - Thread Starter
Senior Member
 
ndaa75's Avatar
 
Join Date: Dec 2011
Location: Caister on Sea, UK
Posts: 493
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 22
Quote:
Originally Posted by Bond 007 View Post

You would be better served by posting that here:

http://www.avsforum.com/t/1408338/official-panasonic-vt50-owners-thread/9840#post_22913104

Why is that? Its the process im after clarification on regardless of brand.

Benq W1080ST Projector, Panasonic TXP55VT30 plasma, Yamaha RXA3020 AVR, Denon DVD-2500BT, Q Acoustics 1010i in 7.1, i1 Pro spectro, i1 Display Pro, Calman 5 Enthusiast, PS3, Xbox 360, Wii

Calibration Management Disc
ndaa75 is offline  
Old 02-02-2013, 06:04 AM
AVS Addicted Member
 
Bond 007's Avatar
 
Join Date: Jun 2012
Location: Cincinnati, OH
Posts: 12,451
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 418 Post(s)
Liked: 878
I see. You are correct.

No, Mr. Bond. I expect you to die!
Bond 007 is offline  
Old 02-02-2013, 06:05 AM - Thread Starter
Senior Member
 
ndaa75's Avatar
 
Join Date: Dec 2011
Location: Caister on Sea, UK
Posts: 493
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 22
Quote:
Originally Posted by Bond 007 View Post

I see. You are correct.

Thank you sir!

Benq W1080ST Projector, Panasonic TXP55VT30 plasma, Yamaha RXA3020 AVR, Denon DVD-2500BT, Q Acoustics 1010i in 7.1, i1 Pro spectro, i1 Display Pro, Calman 5 Enthusiast, PS3, Xbox 360, Wii

Calibration Management Disc
ndaa75 is offline  
Old 02-02-2013, 06:45 AM
AVS Special Member
 
ThePrisoner's Avatar
 
Join Date: Jan 2004
Posts: 2,177
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked: 18
I remember reading that brightness should be set correct using the proper pattern and shouldn't be altered to influence gamma. I'm sure someone with more knowledge than me will reply.

Panasonic 60GT30
Denon X4100
Oppo BDP-103
Definitive Technology BP-8060ST CS-8060HD SR-8040BP ProMonitor 800 (front heights)
SVS 2x PC12-NSD
Dolby Atmos 5.2.2
ThePrisoner is offline  
Old 02-02-2013, 06:47 AM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,126
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Liked: 504
You should not use the brightness adjustment to change gamma. It will lead, in this case, to crushed blacks. You want to be able to see (or at least have the TV display, whether you will see it or not depends on lighting conditions, APL, distance, etc) all the picture content above black. Reducing the brightness to raise gamma will sink that pic detail down into the black.

ISF/THX calibrator with Jeti 1211 reference spectro
Latest reviews:LG 65UB9800Samsung UN65HU8550UN65HU9000, UN85HU8550, LG 55EC9300, LG 55EA8800 (including 3D)

Why I don't publish settings, Review index and rankings, Florida tour Dec '14, Texas tour Jan '15
Chad B is online now  
Old 02-02-2013, 07:52 AM - Thread Starter
Senior Member
 
ndaa75's Avatar
 
Join Date: Dec 2011
Location: Caister on Sea, UK
Posts: 493
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 22
Quote:
Originally Posted by Chad B View Post

You should not use the brightness adjustment to change gamma. It will lead, in this case, to crushed blacks. You want to be able to see (or at least have the TV display, whether you will see it or not depends on lighting conditions, APL, distance, etc) all the picture content above black. Reducing the brightness to raise gamma will sink that pic detail down into the black.

Ok.

So how do i increase gamma without touching the brightness ?

Presumably the process then would be.

1. Set brightness using pluge.
2. Set target gamma in tv menu, ie 2.2, 2.4 etc.
3. Measure gamma from 0-100 lum.
4. Use 10pt gamma controls to fine tune to desired gamma level.

Benq W1080ST Projector, Panasonic TXP55VT30 plasma, Yamaha RXA3020 AVR, Denon DVD-2500BT, Q Acoustics 1010i in 7.1, i1 Pro spectro, i1 Display Pro, Calman 5 Enthusiast, PS3, Xbox 360, Wii

Calibration Management Disc
ndaa75 is offline  
Old 02-02-2013, 02:35 PM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,126
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Liked: 504
I would swap #2 and #1. Changing the TV menu gamma selection often necessitates recalibrating the brightness adjustment.
Your correct options for increasing gamma would be the 10 point control and the 2.2, 2.4 etc gamma selection.

You know, you should be able to avoid major artifacts from the 10 pt control on your VT30, even the EU model that is stuck in low panel brightness. The VT30 has some visible banding in a gradient grayscale ramp even in THX mode, which doesn't have a 10 point adjustment. Basically, any mode that is not calibrated way too blue to cover up the problems is going to have at least some artifacts in a gray ramp. Now, misadjustment of the 10 point controls will certainly add to the problem; however, careful and meticulous calibration of them should give you a decent result with minimal artifacts and banding. If you have access to 5% increment windows where you can read in between the 10 point adjustments, use that as a tool to minimize errors in between bands.

ISF/THX calibrator with Jeti 1211 reference spectro
Latest reviews:LG 65UB9800Samsung UN65HU8550UN65HU9000, UN85HU8550, LG 55EC9300, LG 55EA8800 (including 3D)

Why I don't publish settings, Review index and rankings, Florida tour Dec '14, Texas tour Jan '15
Chad B is online now  
Old 02-02-2013, 03:34 PM - Thread Starter
Senior Member
 
ndaa75's Avatar
 
Join Date: Dec 2011
Location: Caister on Sea, UK
Posts: 493
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 22
Quote:
Originally Posted by Chad B View Post

I would swap #2 and #1. Changing the TV menu gamma selection often necessitates recalibrating the brightness adjustment.
Your correct options for increasing gamma would be the 10 point control and the 2.2, 2.4 etc gamma selection.

You know, you should be able to avoid major artifacts from the 10 pt control on your VT30, even the EU model that is stuck in low panel brightness. The VT30 has some visible banding in a gradient grayscale ramp even in THX mode, which doesn't have a 10 point adjustment. Basically, any mode that is not calibrated way too blue to cover up the problems is going to have at least some artifacts in a gray ramp. Now, misadjustment of the 10 point controls will certainly add to the problem; however, careful and meticulous calibration of them should give you a decent result with minimal artifacts and banding. If you have access to 5% increment windows where you can read in between the 10 point adjustments, use that as a tool to minimize errors in between bands.

Thank you for the in depth answer Chad. Sometimes these things can get a little confusing when youre learning! Cheers again. Have a great weekend.

Benq W1080ST Projector, Panasonic TXP55VT30 plasma, Yamaha RXA3020 AVR, Denon DVD-2500BT, Q Acoustics 1010i in 7.1, i1 Pro spectro, i1 Display Pro, Calman 5 Enthusiast, PS3, Xbox 360, Wii

Calibration Management Disc
ndaa75 is offline  
 
Thread Tools


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