Increase gamma by lowering brightness - AVS Forum | Home Theater Discussions And Reviews
Baselworld is only a few weeks away. Getting the latest news is easy, Click Here for info on how to join the Watchuseek.com newsletter list. Follow our team for updates featuring event coverage, new product unveilings, watch industry news & more!


Forum Jump: 
 
Thread Tools
post #1 of 10 Old 02-02-2013, 03:34 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
 
post #2 of 10 Old 02-02-2013, 03:48 AM
AVS Addicted Member
 
Bond 007's Avatar
 
Join Date: Jun 2012
Location: Cincinnati, OH
Posts: 13,311
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 772 Post(s)
Liked: 1087
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 online now  
post #3 of 10 Old 02-02-2013, 04:54 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  
post #4 of 10 Old 02-02-2013, 05:04 AM
AVS Addicted Member
 
Bond 007's Avatar
 
Join Date: Jun 2012
Location: Cincinnati, OH
Posts: 13,311
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 772 Post(s)
Liked: 1087
I see. You are correct.

No, Mr. Bond. I expect you to die!
Bond 007 is online now  
post #5 of 10 Old 02-02-2013, 05:05 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  
post #6 of 10 Old 02-02-2013, 05:45 AM
AVS Special Member
 
ThePrisoner's Avatar
 
Join Date: Jan 2004
Location: Jupiter and beyond infinite
Posts: 2,288
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
Liked: 44
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.

Dolby Atmos 5.2.4
Denon AVR-4100X - Oppo BDP-103 - Panasonic 60GT30 - Definitive Technology BP-8060ST
Definitive Technology CS-8060HD - Definitive Technology SR-8040BP -
Definitive Technology PM800 (4) ceiling mounted - SVS PC12-NSD (2)


2 Channel - Marantz PM8004 - Oppo BDP-105D - Music Hall MMF-5.1 - iFi Phono - Pioneer SP-BS22LR
ThePrisoner is online now  
post #7 of 10 Old 02-02-2013, 05:47 AM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,301
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 255 Post(s)
Liked: 803
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 65EG9600, Sony XBR75X940C, Samsung UN65JS9500
Copied settings measured, LG OLED calibration tips, Review index and rankings
Chad B is online now  
post #8 of 10 Old 02-02-2013, 06:52 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  
post #9 of 10 Old 02-02-2013, 01:35 PM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,301
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 255 Post(s)
Liked: 803
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 65EG9600, Sony XBR75X940C, Samsung UN65JS9500
Copied settings measured, LG OLED calibration tips, Review index and rankings
Chad B is online now  
post #10 of 10 Old 02-02-2013, 02:34 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  
Sponsored Links
Advertisement
 
Reply Display Calibration

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