| Author |
Message |
dropzone7
Joined: 12 Jun 2007
Posts: 1069
Location: Charlotte, NC
|
| Posted: Tue Mar 03, 2009 7:16 pm Post subject: |
|
|
I broke out the Eye One last night and had a go at grayscale on my new 817p entry. It's been a while since I tried this but Kal's guide was a good refresher and it wan't long before I was getting the hang of it. I did about 5 sets of grayscale meaurements with the final 4 sets being minor tweaks of the first. On my final try I got a gamma of 2.20 after having started at 1.74 gamma. The thing that I could not seem to get right was my 0IRE and 10IRE readings. They are visibly red and I could not get a Delta E anywhere near my other IRE's. Any idea what I might change to get these in line? I'm using the Moome XG HDMI card and have gamma set correctly on that. I was able to get the 2.20 gamma reading by bringing down my brightness level through the VP50 scaler. My 0IRE and 10IRE readings were better when the brightness was higher but gamma was not correct.
_________________
"Coffee is for Closers."
|
|
| Back to top |
|
 |
kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 18114
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
|
| Posted: Tue Mar 03, 2009 7:32 pm Post subject: |
|
|
| dropzone7 wrote: | | I broke out the Eye One last night and had a go at grayscale on my new 817p entry. It's been a while since I tried this but Kal's guide was a good refresher and it wan't long before I was getting the hang of it. I did about 5 sets of grayscale meaurements with the final 4 sets being minor tweaks of the first. On my final try I got a gamma of 2.20 after having started at 1.74 gamma. The thing that I could not seem to get right was my 0IRE and 10IRE readings. They are visibly red and I could not get a Delta E anywhere near my other IRE's. Any idea what I might change to get these in line? I'm using the Moome XG HDMI card and have gamma set correctly on that. I was able to get the 2.20 gamma reading by bringing down my brightness level through the VP50 scaler. My 0IRE and 10IRE readings were better when the brightness was higher but gamma was not correct. |
You can't trust readings at such a low stimulus level (0 or 10 IRE relatively speaking) even with the very expensive meters so you should just be doing them by eye.
Kal
_________________
Support our site by using our affiliate links. We thank you!
My basement/HT/bar/brewery build 2.0
|
|
| Back to top |
|
|
dropzone7
Joined: 12 Jun 2007
Posts: 1069
Location: Charlotte, NC
|
| Posted: Tue Mar 03, 2009 7:45 pm Post subject: |
|
|
| kal wrote: | | dropzone7 wrote: | | I broke out the Eye One last night and had a go at grayscale on my new 817p entry. It's been a while since I tried this but Kal's guide was a good refresher and it wan't long before I was getting the hang of it. I did about 5 sets of grayscale meaurements with the final 4 sets being minor tweaks of the first. On my final try I got a gamma of 2.20 after having started at 1.74 gamma. The thing that I could not seem to get right was my 0IRE and 10IRE readings. They are visibly red and I could not get a Delta E anywhere near my other IRE's. Any idea what I might change to get these in line? I'm using the Moome XG HDMI card and have gamma set correctly on that. I was able to get the 2.20 gamma reading by bringing down my brightness level through the VP50 scaler. My 0IRE and 10IRE readings were better when the brightness was higher but gamma was not correct. |
You can't trust readings at such a low stimulus level (0 or 10 IRE relatively speaking) even with the very expensive meters so you should just be doing them by eye.
Kal |
Okay, but won't that just mess up the readings that are good? My Delta E on 100IRE was 1.7 which I thought was pretty darn good.
Edit. From the guide. Sorry I forgot about this Kal.
"The low end (especially 20 IRE and below) is especially problematic on just about every display. In fact, contrary to what we've said before, you're almost better off using your eyes to judge the readings at 10 and 20 IRE as most sensors (including the more expensive ones) simply don't do a very good job of measuring light output at the low end. If your greys at 10 and 20 IRE look reasonably grey and 30 IRE measures close to D65 then good enough!"
Oh well, back to the drawing board. You also mention that it's better to sacrifice 80IRE and above to get the lower IRE's correct so I will try a little "eyeballing" of those values tonight.
_________________
"Coffee is for Closers."
|
|
| Back to top |
|
|
dave999z
Joined: 01 Mar 2009
Posts: 5
|
| Posted: Fri Mar 06, 2009 4:38 pm Post subject: |
|
|
|
Does it matter what my room lighting is like when I do a calibration (i.e., will it affect the I1's readings?)?
|
|
| Back to top |
|
|
dropzone7
Joined: 12 Jun 2007
Posts: 1069
Location: Charlotte, NC
|
| Posted: Fri Mar 06, 2009 4:58 pm Post subject: |
|
|
| dave999z wrote: | | Does it matter what my room lighting is like when I do a calibration (i.e., will it affect the I1's readings?)? |
Yes, it matters a lot. You only want the meter seeing light that is produced by your display (TV, projector, etc.). If you have lights on in the room or sunhine coming in through a window then your contrast reading is going to be higher than what your display is actaully putting out. Remember that you are trying to target a range of foot lamberts of light in your measurment and you want that to be light coming from your display only, not any other source. Having other light sources present in the room while doing a calibration would be kind of like taking sound measurements from your speakers with a blender running in the room.
_________________
"Coffee is for Closers."
|
|
| Back to top |
|
|
dave999z
Joined: 01 Mar 2009
Posts: 5
|
| Posted: Fri Mar 06, 2009 7:32 pm Post subject: |
|
|
| dropzone7 wrote: | | dave999z wrote: | | Does it matter what my room lighting is like when I do a calibration (i.e., will it affect the I1's readings?)? |
Yes, it matters a lot. You only want the meter seeing light that is produced by your display (TV, projector, etc.). If you have lights on in the room or sunhine coming in through a window then your contrast reading is going to be higher than what your display is actaully putting out. Remember that you are trying to target a range of foot lamberts of light in your measurment and you want that to be light coming from your display only, not any other source. Having other light sources present in the room while doing a calibration would be kind of like taking sound measurements from your speakers with a blender running in the room. |
it just seems like since the I1 is suctioned directly onto the screen, how is additional light in the room even going to reach the sensor.
i guess there's a easy way to tell. start taking readings, turn the light on or off, and see if the readings change at all.
|
|
| Back to top |
|
|
dropzone7
Joined: 12 Jun 2007
Posts: 1069
Location: Charlotte, NC
|
| Posted: Fri Mar 06, 2009 7:39 pm Post subject: |
|
|
| dave999z wrote: |
it just seems like since the I1 is suctioned directly onto the screen, how is additional light in the room even going to reach the sensor.
i guess there's a easy way to tell. start taking readings, turn the light on or off, and see if the readings change at all. |
Well, in that case you may be right. I have never used the sensor on anything but a front projector so I'm not using the suction cups and the sensor is freely open to the room, pointed at my screen. Even with those suction cups it's not making a gasket type seal around the screen so light can get in from sources in the room. I think your idea of trying it both ways makes the most sense. Get a reading with the lights off and then turn them on to see what happens. Remember to allow the meter to update at least two or three times so that you are sure the meter was not in the process of reading when you made a change.
_________________
"Coffee is for Closers."
|
|
| Back to top |
|
|
Jay-C
Joined: 17 Mar 2009
Posts: 3
|
|
| Back to top |
|
|
mark143
Joined: 18 Mar 2009
Posts: 2
|
| Posted: Wed Mar 18, 2009 12:52 pm Post subject: secondary color measurement |
|
|
Hi Kal!
I was wondering which patterns to use in AVIA II or DVE in measuring CYM? Problem with Avia, it uses color fields instead of windows. Will there be an effect on my Display? I'm using Pioneer KRP-600M Plasma
Thanks in advance
|
|
| Back to top |
|
|
kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 18114
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
|
| Posted: Wed Mar 18, 2009 1:46 pm Post subject: |
|
|
Jay-C/Mark,
This thread is for questions specifically about the steps in the guide. Questions about specific displays and how they work as well as test discs not covered in my guide (AVIA II) are best asked in a separate new thread. I don't know the answers. Sorry! You're likely to get more responses in a separate thread as well.
Kal
_________________
Support our site by using our affiliate links. We thank you!
My basement/HT/bar/brewery build 2.0
Last edited by kal on Wed Mar 18, 2009 4:22 pm; edited 1 time in total
|
|
| Back to top |
|
|
Jay-C
Joined: 17 Mar 2009
Posts: 3
|
| Posted: Wed Mar 18, 2009 1:50 pm Post subject: |
|
|
Hi Kal,
thank you for info, my topic is now moved to a separate new thread.
|
|
| Back to top |
|
|
jarseneau
Joined: 06 Nov 2007
Posts: 323
Location: WI
|
| Posted: Wed Mar 18, 2009 5:28 pm Post subject: NEC greyscale controls |
|
|
Maybe it doesn't really matter which way you go but I've found 2 sets of controls to adjust greyscale on NECs. One set is global (Bright bias for Low end, Drive for High end), affecting all signal entries and the other is Signal entry specific (White Balance WHT/BLK). I tend to favor the BIAS/DRIVE controls to get the calibration to cover all entries but wondering if there is reason to use the White Balance controls.
_________________
Jerry
|
|
| Back to top |
|
|
halli
Joined: 22 Mar 2009
Posts: 1
Location: Iraq
|
| Posted: Sun Mar 22, 2009 8:23 pm Post subject: Re: 'Greyscale & Colour Calibration for Dummies' Q/A thr |
|
|
|
do broadcast monitors in TV studios also need grey scale calibration?? or they are already calibrated as they are for broadcast business??cast business??
|
|
| Back to top |
|
|
Poundman
Joined: 10 Mar 2009
Posts: 1
|
| Posted: Mon Mar 30, 2009 6:48 pm Post subject: Pioneer RPTV CRT |
|
|
|
I have a Pioneer Elite Pro610hd RPTV CRT that I'm trying to calibrator greyscale. I have been told that the screen trimpots can be used like a RGBLowEnd/Cut adjustment. can anyone confirm? I have also been told I should set my blacklevel in user menu back to 0 then use this trimpots to adjust blacklevel (boost the energy to the aging CRTS) before I start. Any other ideas?
|
|
| Back to top |
|
|
Selfar
Joined: 09 Apr 2009
Posts: 1
Location: Cairo
|
| Posted: Thu Jun 04, 2009 12:38 pm Post subject: |
|
|
Thank you very much for this guide. I studied well and had my first calibration last night. I just have some questions:
In case of Projector, the room should be as dark as possible. What about others such as Plasma, do I calibrate using my viewing lighting conditions? I did not find a clear answer in the guide.
When we start the Greyscale calibration, do I set the color and Tint to Zero and then go through the process; Contrast, Brightness, RGBhighEnd and RGBlowEnd?
I got to step 8.5, i adjusted the Red (step 8.2) and then the green and blue as a percentage of the Y reading (71% and 8%). Then do i readjust all Primary again coupled with the secondary colors through the x,y values? I am really confused, Kindly clarify?
_________________
Selfar
Last edited by Selfar on Sat Jun 06, 2009 5:24 pm; edited 1 time in total
|
|
| Back to top |
|
|
mcb01
Joined: 13 Dec 2008
Posts: 2
|
| Posted: Sat Jun 06, 2009 2:32 am Post subject: error? |
|
|
Hi Kal,
I think there is a mistake in the guide. In section 8.3, you wrote:
For SDTV - REC 601 (NTSC) the magenta target is x=0.314 / y=0.154
But in the charts below that in section 8.5, you have the y coordinate as 0.161.
|
|
| Back to top |
|
|
kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 18114
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
|
| Posted: Sat Jun 06, 2009 2:34 pm Post subject: Re: error? |
|
|
| mcb01 wrote: | Hi Kal,
I think there is a mistake in the guide. In section 8.3, you wrote:
For SDTV - REC 601 (NTSC) the magenta target is x=0.314 / y=0.154
But in the charts below that in section 8.5, you have the y coordinate as 0.161. |
Thanks! Fixed! It was wrong in section 8.3. The REC 601 (NTSC) target for magenta is indeed x=03.14, y=0.161.
A note to the previous 3-4 posters asking questions related to their displays: This thread is for questions about the guide I've put together. I will not answer any questions specific to your calibration or look at resulting calibrations. Sorry. I don't have time for this nor do I know how the controls in the 1000's of TVs in the world work. You're best to start a new thread. It's more likely that someone will see it and answer.
| Selfar wrote: | | In case of Projector, the room should be as dark as possible. What about others such as Plasma, do I calibrate using my viewing lighting conditions? I did not find a clear answer in the guide. |
Whatever condition you use to watch the display in which should also be fairly dark. Doesn't really matter much for direct view sets since you'll be placing the sensor right against the surface so there shouldn't be much (if any) stray light entering the sensor.
| Quote: | | When we start the Greyscale calibration, do I set the color and Tint to Zero and then go through the process; Contrast, Brightness, RGBhighEnd and RGBlowEnd? |
No, zero tint/color would not be right. Set them to defaults.
| Quote: | | I got to step 8.5, i adjusted the Red (step 8.2) and then the green and blue as a percentage of the Y reading (71% and 8%). Then do i readjust all Primary again coupled with the secondary colors through the x,y values? I am really confused, Kindly clarify? |
Run through the entire guide. Then run through it again until there's no more adjustments required. It's an iterative process.
Kal
_________________
Support our site by using our affiliate links. We thank you!
My basement/HT/bar/brewery build 2.0
|
|
| Back to top |
|
|
cfduarte
Joined: 29 Jun 2009
Posts: 1
|
| Posted: Mon Jun 29, 2009 10:43 pm Post subject: |
|
|
First of all, great work! Thanks!
I've been playing around with the guide, HCFR and my (LG) plasma and I just have some doubts.
My plasma has ISF controls for specific primary and secondary colours, with a colour (saturation?) and tint (hue?) controls for each one. In the guide you mention adjusting then in the (Red), Green, Blue, Yellow, Cyan, and Magenta order after adjusting the "lightness" for the primaries.
Since I have no "lightness" control, am I right to assume that I can just set the saturation and hue for each colour, since the lightness has been set previously through the grayscale calibration?
UPDATE: Apparently LG Plasmas only have "2D" adjustment for colours, so no lightness control. From what I gathered from other sources, the Colour control adjusts BOTH saturation and lightness
Also, what is the effect of adjusting saturation and hue on the colour coordinates? (i.e. does saturation affect x and hue y)
Thanks!
|
|
| Back to top |
|
|
skyerjoe
Joined: 11 Dec 2008
Posts: 19
|
| Posted: Tue Aug 18, 2009 11:00 am Post subject: |
|
|
| Quote: | | A note to the previous 3-4 posters asking questions related to their displays: This thread is for questions about the guide I've put together. I will not answer any questions specific to your calibration or look at resulting calibrations. Sorry. I don't have time for this nor do I know how the controls in the 1000's of TVs in the world work. You're best to start a new thread. It's more likely that someone will see it and answer. |
@KAL
You should mention this in your topic dont you? 
greetz skyerjoe [/code]
|
|
| Back to top |
|
|
skyerjoe
Joined: 11 Dec 2008
Posts: 19
|
| Posted: Wed Aug 19, 2009 1:55 pm Post subject: |
|
|
I have an problem id like to do the 6.2 step properly, but something doesnt fit.
| Quote: | ostPosted: Sat Apr 26, 2008 7:48 pm Post subject: Reply with quote
Part 6: Adjusting Greyscale
Ok, now for the 'meat' of this guide: Adjusting the actual greyscale!
The basic concept behind adjusting greyscale is pretty straightforward: We alternate displaying a reasonably dark and light patterns and adjust the RGBLowEnd and RGBHighEnd controls until the x and y values are as close to the D65 point as possible. We then hope and cross our fingers that the rest of the greyscale from 10 to 100 IRE follows suite and tracks close to D65 as well.
S
STEP 6.2: On your Digital Video Essentials: HD Basics test disc and skip to the bright 80 IRE window pattern by choosing the disc's menu option "Complete Program Menu" -> "Advanced Video Test Patterns" -> 1080p or 720p -> "Window 80% w/ PLUGE". 80 IRE means that the pattern is 80% white and 'window' means that this pattern only uses a small portion of the screen (typically 10-18%). It looks like this:
STEP 6.3: Adjust the red and blue RGBHighEnd controls on your display until all three RGB Level bars are at 100% or very close. You'll have to play around the first time to figure out which way to adjust the controls to add or remove red and blue as all displays work differently. Once all three are close to 100% you should be close to the D65 point (x=0.313 and y=0.329).
Note that we only adjust red and blue. Green is typically the reference and should be left alone as adjusting the green RGBHighEnd control (and balancing the red and blue levels to match) has the same effect as simply adjusting the overall contrast.
Ok! So now the 80 IRE point is set correctly to D65! Don't get too excited, you're going to adjust it again very soon ...
|
I try to bring the 3 RGB Colours in one Level, but on Colour is totally out of. The Red Level is under zero, and if i raise the Red Adjustment on full, the scale only raises between 10-20 %
I have an Samsung Le 40 A656
So okay maybe my Tv isn't work properly so i tred an other TV an Plasma Display Pioneer PDP-436 RXE ( a little bit older)
partically the same as before, the red value is totally out of.
Is my eye one still good enough for a garbage dump?
Or whats wrong?
Thnx for help skyerjoe
|
|
| Back to top |
|
|
|
|
