AE4000 Calibration help please - Page 2 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #31 of 44 Old 06-16-2012, 04:50 AM
Member
 
dominickwok's Avatar
 
Join Date: Jul 2009
Posts: 188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by jeansibelius24 View Post

Just wondered, do I set the colour temperature to -3 then set the colour and tint using a test pattern with the blue filter before moving onto setting the primaries, or do I leave the settings on zero?

If you're using a meter, it is not necessary to use a blue filter. You can leave the main Colour and Tint controls at 0 to start with. I set Colour = +1 and Tint = -1 simply because it can minimize the changes that I needed to make to the tint (for Hue), colour (for Satuation), and brightness (for Lightness) controls for the individual RGBCMY colours inside the AE4000's CMS (which is using the HSL model). If you discover that you need to make a big increase of Brightness to a, e.g. primary colour say Green, you can increase the main Colour control (which has the main affect on Lightness of all the primaries and secondaries) so that a less +ve Brightness value is required on Green (but of course, at the same time, a lower Brightness value is required on all the other primaries & secondaries too).
Quote:
Originally Posted by jeansibelius24 View Post

My contrast is currently on the default setting generating 10.6ftL with a 100% Ire pattern, is that good enough as a starting point?

That should be a good starting point (assuming you mean setting Contrast = 0, which is the default in Cinema 1); but you should check your gamma to see whether it is still a too high setting which gives you a gamma drop at the high end (typically when the unit is running out of Red in the high end). In my case, I set Contrast to -2 as a compromise.
Quote:
Originally Posted by jeansibelius24 View Post

When setting the CMS RGB levels with the 75% saturation windows do I just adjust the colour slider to attain the desired RGB percentages as I noticed there was also a tint and brightness control too?

No. In AE4000's CMS, the "Tint" control is for adjusting Hue, "Colour" control is for adjusting Satuation, and "Brightness" control is for adjusting Lightness. You can refer to the following post for some fundamentals:

http://www.avsforum.com/t/852536/basic-guide-to-color-calibration-using-a-cms-updated-and-enhanced
dominickwok is offline  
Sponsored Links
Advertisement
 
post #32 of 44 Old 06-23-2012, 07:52 PM - Thread Starter
Member
 
jeansibelius24's Avatar
 
Join Date: May 2012
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
After all these useful tips I thought that working my way through the steps wouldn't be too difficult, however trying just to set the correct 75% RGB saturation levels has proven to be a real headache.

I just wondered if I have set the sliders incorrectly because while trying to achieve the correct Red saturation level I had to reduce colour to -25, tint -3 amd brightness +10 (R 378% G 24% B 24%). For Green I had to reduce the colour down to -30 and increase the brightness to +20 which are the minimum and maximums of the sliders, even then I couldn't quite achieve the required R and B percentages which were both 2% under. The biggest problem however was Blue which I couldn't even get close to. According to the spreadsheet Blue needs to be 555% and reducing the colour slider completely reduced it only to 780%.

Also looking at the colours afterwards they looked really washed out.

These are the settings I used before attempting the CMS RGB saturation levels as recommended in a previous post.

Cinema1 mode
Contrast -2
Brightness +1
Colour +1
Tint -1
Colour Temperature -3
Dynamic Iris: Off

Any help would be really appreciated as the frustration levels are hitting a new high.

Thanks
jeansibelius24 is offline  
post #33 of 44 Old 06-24-2012, 06:09 AM
Member
 
dominickwok's Avatar
 
Join Date: Jul 2009
Posts: 188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by jeansibelius24 View Post

After all these useful tips I thought that working my way through the steps wouldn't be too difficult, however trying just to set the correct 75% RGB saturation levels has proven to be a real headache.
I just wondered if I have set the sliders incorrectly because while trying to achieve the correct Red saturation level I had to reduce colour to -25, tint -3 amd brightness +10 (R 378% G 24% B 24%). For Green I had to reduce the colour down to -30 and increase the brightness to +20 which are the minimum and maximums of the sliders, even then I couldn't quite achieve the required R and B percentages which were both 2% under. The biggest problem however was Blue which I couldn't even get close to. According to the spreadsheet Blue needs to be 555% and reducing the colour slider completely reduced it only to 780%.
Also looking at the colours afterwards they looked really washed out.
These are the settings I used before attempting the CMS RGB saturation levels as recommended in a previous post.
Cinema1 mode
Contrast -2
Brightness +1
Colour +1
Tint -1
Colour Temperature -3
Dynamic Iris: Off
Any help would be really appreciated as the frustration levels are hitting a new high.
Thanks

What type of screen you're using? Besides your viewing environment (e.g. walls, ceiling, floor, furniture, etc.), the screen is one of the very significant factors that can change the colors seen by your eyes (and the meter of course). I'm using a matt white screen with gain ~0.8, which is famous to be best perserving color accuracy of the reflected light (vs. other types such as gray screen, etc.). I'm in no way required to use your extreme values in the AE4000 CMS. HItting 75% saturation targets is just like a piece of cake for me. Below are my values for your reference.

Colour / Tint / Brightness
R: -14 / 0 / -6
G: -11 / -6 / +10
B: +1 / +7 / 0
C: -12 / +4 / +11
M: -10 / -5 / -7
Y: -9 / +8 / +3
dominickwok is offline  
post #34 of 44 Old 06-24-2012, 02:22 PM - Thread Starter
Member
 
jeansibelius24's Avatar
 
Join Date: May 2012
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks for posting those settings, I will try them and see if they give me a better result.

My screen is a Grandview Cyber 92", here is the link to the product - http://www.cyberscreens.co.uk/cyberpulldownscreens.htm

The room is painted with flat matt, the ceiling dark grey and the walls dark green. I also use a blackout blind with black curtains. However I do have books on the floor which could possibly be reflecting light back onto the screen.

The meter I am using is the i1Display Pro III retail with the latest version of HCFR.

Think that I might have to give up on trying to calibrate the projector as it is really becoming a pain.
jeansibelius24 is offline  
post #35 of 44 Old 06-26-2012, 09:48 AM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,068
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 347
OK, I just calibrated a 4000U yesterday and although I didn't take notes of my procedure, there are a few things I wanted to post here.

It was light starved, as it was projecting a large image on a DIY gray screen ("Black Widow") painted wall. I don't know the gain of that paint, but I wouldn't be surprised if it was negative gain.

Before cal it was putting out around 9.9 fL, with a very low gamma and poor color. It was in Normal mode with minimal modifications. Lamp power was on normal (high).

My only option for calibration was Normal mode, since switching to the more accurate Cinema1 mode would cut light output to well below 5 fL. Probably end up around 3 fL after cal, which is unwatchable. Normal has very significant red drop off above 60-70% or so, but it's still a ton better than trying to watch 3-5 fL.

I calibrated to D75 rather than D65. That minimized the visibility of the unavoidable red dropoff.

With brightness (set with a low APL pluge pattern) at +4 and contrast at -3, and all color temp and white balance controls at default, the 10 point adjustment tracks well and is very useful for flattening out the gamma and grayscale throughout most of the range. If you want to use the multipoint, It's important to NOT adjust the R,G,B high and low white balance adjustments. Otherwise, the different colors will start getting displaced by differing amounts. In other words, if you adjust the white balance or the color temp adjustment much then when you try to adjust the multipoint you will find that the 80% red control may actually effect 95%, the 80% green may adjust 70%, and the 80% blue might adjust 85%, etc. I used the multipoint to flatten gamma over the entire range and flatten grayscale from 10-70%. Above 70%, the red ran out of steam, but as mentioned calibrating to D75 made that much less apparent. Dynamic Iris should be turned off for these adjustments.

With GS and gamma as good as could be, I moved on to CMS. The measurements, at least the conventional 75% levels/100% saturation measurements, indicated Red should be turned down in level and it's hue should be swung toward magenta. Don't do this! It results in pale and purplish people. I ended up taking the overall color control down a few clicks, but not as much as the measurements indicated, and then I actually gave the red hue just a tiny (2 click) nudge toward yellow. Flesh tones looked fantastic. The other primaries and the secondary's subjective looks followed matched up much better with the measurements, so calibrating the green CMS by the measurements eliminated the neon green grass in stadiums and ball fields. The magenta was also way off before cal and looked much better after CMS adjustment.

I ended up with just a tiny bit over 10 fL of light output and a dramatic transformation and startling improvement in PQ.

It's true, when projecting the 4000u on a low gain/large screen, the normal rules of calibration can not be followed. But the picture can still look subjectively very good, and it can be a huge improvement over stock Normal mode.

touring calibrator
Jeti 1211

Latest reviews:


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Chad B is online now  
post #36 of 44 Old 06-27-2012, 03:43 PM - Thread Starter
Member
 
jeansibelius24's Avatar
 
Join Date: May 2012
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Hi, I tried the RBCMY CMS settings in a previous post last night. The image looked fine to me but to be honest I don't know what to look for when viewing the image and whether or not it's closer to the correct saturation levels. I compared it to Color1 mode and they both looked very similar with the calibrated Cinema1 mode looking a bit darker with slightly less red in it. Is there a way I can tell if the primaries and secondaries saturation levels are improved, perhaps I could post a particular graph here from HCFR?

Also my RGB levels are now getting much closer with the exception of red dipping at 10% IRE and all three a bit untidy at 20% IRE. To try and correct this do I display a 10% IRE window and try and get the RGB bars to match up at 100% or will that throw off the other settings?

Thanks
jeansibelius24 is offline  
post #37 of 44 Old 06-28-2012, 08:20 AM
Member
 
dominickwok's Avatar
 
Join Date: Jul 2009
Posts: 188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by jeansibelius24 View Post

Hi, I tried the RBCMY CMS settings in a previous post last night. The image looked fine to me but to be honest I don't know what to look for when viewing the image and whether or not it's closer to the correct saturation levels. I compared it to Color1 mode and they both looked very similar with the calibrated Cinema1 mode looking a bit darker with slightly less red in it. Is there a way I can tell if the primaries and secondaries saturation levels are improved, perhaps I could post a particular graph here from HCFR?
Also my RGB levels are now getting much closer with the exception of red dipping at 10% IRE and all three a bit untidy at 20% IRE. To try and correct this do I display a 10% IRE window and try and get the RGB bars to match up at 100% or will that throw off the other settings?
Thanks

You can do a full measurement of grayscale and a sweep of saturation levels (0% / 25% / 50% / 75% / 100%) for all the primaries and secondaries (using the saturation patterns in AVSHD709 disc) and then see how your particular AE4000 performs with respect to the gamut tracking. I'm sorry for not mentioning before but in fact you SHOULDN'T copy my settings because we do not have the same viewing environment, screen, bulb age, etc. etc. which can significantly affect your image's colors. By the way, I attach here some graphs that I extracted from the Stereomandan spreadsheet and the HCFR software (after I took the measurement of my calibrated Cinema 1 mode) in the PDF here, just to show you that in fact (it might be varies from unit to unit) how AE4000 is capable to have linear tracking of saturation, hue and luminance of colors up to 75% saturation level, together with a good tracking on the D65 white point and gamma. I'm using a i1Pro-profiled Spyder3 for calibration/measurement.

Even for colorimeter such as Spyder3, which can have much better light sensitivity vs. a spectro such as i1Pro, I will not trust any readings below 30% - trust your eyes instead.

Gamut.jpg 106k .jpg file

Color Luminance.jpg 93k .jpg file

Grayscale.jpg 84k .jpg file

Gamma.jpg 79k .jpg file
dominickwok is offline  
post #38 of 44 Old 06-28-2012, 11:37 AM
Member
 
morty343's Avatar
 
Join Date: Feb 2006
Posts: 50
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by Chad B View Post

OK, I just calibrated a 4000U yesterday and although I didn't take notes of my procedure, there are a few things I wanted to post here.
It was light starved, as it was projecting a large image on a DIY gray screen ("Black Widow") painted wall. I don't know the gain of that paint, but I wouldn't be surprised if it was negative gain.
Before cal it was putting out around 9.9 fL, with a very low gamma and poor color. It was in Normal mode with minimal modifications. Lamp power was on normal (high).
My only option for calibration was Normal mode, since switching to the more accurate Cinema1 mode would cut light output to well below 5 fL. Probably end up around 3 fL after cal, which is unwatchable. Normal has very significant red drop off above 60-70% or so, but it's still a ton better than trying to watch 3-5 fL.
I calibrated to D75 rather than D65. That minimized the visibility of the unavoidable red dropoff.
With brightness (set with a low APL pluge pattern) at +4 and contrast at -3, and all color temp and white balance controls at default, the 10 point adjustment tracks well and is very useful for flattening out the gamma and grayscale throughout most of the range. If you want to use the multipoint, It's important to NOT adjust the R,G,B high and low white balance adjustments. Otherwise, the different colors will start getting displaced by differing amounts. In other words, if you adjust the white balance or the color temp adjustment much then when you try to adjust the multipoint you will find that the 80% red control may actually effect 95%, the 80% green may adjust 70%, and the 80% blue might adjust 85%, etc. I used the multipoint to flatten gamma over the entire range and flatten grayscale from 10-70%. Above 70%, the red ran out of steam, but as mentioned calibrating to D75 made that much less apparent. Dynamic Iris should be turned off for these adjustments.
With GS and gamma as good as could be, I moved on to CMS. The measurements, at least the conventional 75% levels/100% saturation measurements, indicated Red should be turned down in level and it's hue should be swung toward magenta. Don't do this! It results in pale and purplish people. I ended up taking the overall color control down a few clicks, but not as much as the measurements indicated, and then I actually gave the red hue just a tiny (2 click) nudge toward yellow. Flesh tones looked fantastic. The other primaries and the secondary's subjective looks followed matched up much better with the measurements, so calibrating the green CMS by the measurements eliminated the neon green grass in stadiums and ball fields. The magenta was also way off before cal and looked much better after CMS adjustment.
I ended up with just a tiny bit over 10 fL of light output and a dramatic transformation and startling improvement in PQ.
It's true, when projecting the 4000u on a low gain/large screen, the normal rules of calibration can not be followed. But the picture can still look subjectively very good, and it can be a huge improvement over stock Normal mode.

Thank you Chad,

I'm a little confused by your referral to the "RGB high and low white balance adjustments", and the "color temp adjustments", and what these are. Are you referring to the sliders for the individual primaries' brightness and contrast in the advanced menu, and the color temperature slider in the picture basic menu? Or are you referring to the 10-point gamma scale, saying that only the Y should be adjusted, and the gammas for RGB should not be individually adjusted. If it's the former, I don't understand how D75 can be attained without adjusting these sliders, because HCFR would report the RGB levels as not being relatively equal unless they are tweaked. Or is using the RGB gamma 10-point adjustments an alternative to playing with the RGB brightness/contrast, and you're saying that these can be left at 0 and greyscale balance can be achieved by solely adjusting RGB gammas?
morty343 is offline  
post #39 of 44 Old 06-28-2012, 12:03 PM
AVS Special Member
 
Chad B's Avatar
 
Join Date: Oct 2002
Location: Piqua, OH
Posts: 2,068
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 347
Quote:
Originally Posted by morty343 View Post

Thank you Chad,
I'm a little confused by your referral to the "RGB high and low white balance adjustments", and the "color temp adjustments", and what these are. Are you referring to the sliders for the individual primaries' brightness and contrast in the advanced menu, and the color temperature slider in the picture basic menu? Or are you referring to the 10-point gamma scale, saying that only the Y should be adjusted, and the gammas for RGB should not be individually adjusted. If it's the former, I don't understand how D75 can be attained without adjusting these sliders, because HCFR would report the RGB levels as not being relatively equal unless they are tweaked. Or is using the RGB gamma 10-point adjustments an alternative to playing with the RGB brightness/contrast, and you're saying that these can be left at 0 and greyscale balance can be achieved by solely adjusting RGB gammas?

Yes, I am referring to the sliders for the R, G, and B brightness and contrast in the advanced menu and also the color temperature slider in the basic menu.
I am not at all familiar with HCFR, so any questions specific to that I will leave to others. However, yes, it's easy to get D75 (from 10-70%) by adjusting just the 10 pt adjustment. You will have to use each color's 10 pt adjustment. Also at the same time it can be used to flatten out the gamma, which was very important to getting the PQ improvement.
So to recap, if you want to try this method, leave the R/G/B brightness and contrast at or near 0 (I ended up turning blue brightness up by a click, but that was just enough to help smooth things out a bit and was not enough to cause problems). Leave the Color temp slider at default. Use all colors and the Y controls of the 10 point adjustment to achieve a flat gamma across the whole range and also D75 from 10-70%. Keep G and B tracking relatively close together from 80-100, but you won't be able to maintain red at those levels.

I am not recommending this practice for all calibrations. It's a deviation from the norm and should only be used on 4000us that would be struggling with weak light output in Cinema 1 mode.

touring calibrator
Jeti 1211

Latest reviews:


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Chad B is online now  
post #40 of 44 Old 06-28-2012, 03:21 PM
Member
 
morty343's Avatar
 
Join Date: Feb 2006
Posts: 50
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Excellent, thanks very much for the suggestions! Very much appreciated.
morty343 is offline  
post #41 of 44 Old 06-28-2012, 03:24 PM - Thread Starter
Member
 
jeansibelius24's Avatar
 
Join Date: May 2012
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by dominickwok View Post

You can do a full measurement of grayscale and a sweep of saturation levels (0% / 25% / 50% / 75% / 100%) for all the primaries and secondaries (using the saturation patterns in AVSHD709 disc) and then see how your particular AE4000 performs with respect to the gamut tracking. I'm sorry for not mentioning before but in fact you SHOULDN'T copy my settings because we do not have the same viewing environment, screen, bulb age, etc. etc. which can significantly affect your image's colors. By the way, I attach here some graphs that I extracted from the Stereomandan spreadsheet and the HCFR software (after I took the measurement of my calibrated Cinema 1 mode) in the PDF here, just to show you that in fact (it might be varies from unit to unit) how AE4000 is capable to have linear tracking of saturation, hue and luminance of colors up to 75% saturation level, together with a good tracking on the D65 white point and gamma. I'm using a i1Pro-profiled Spyder3 for calibration/measurement.
Even for colorimeter such as Spyder3, which can have much better light sensitivity vs. a spectro such as i1Pro, I will not trust any readings below 30% - trust your eyes instead.
Gamut.jpg 106k .jpg file
Color Luminance.jpg 93k .jpg file
Grayscale.jpg 84k .jpg file
Gamma.jpg 79k .jpg file

I just wondered if I do a sweep of the primary and secondary saturation levels do I use the saturation luminance graph in HCFR and try and get each as flat as possible. If yes do I go through each saturation pattern from 10-100% and adjust the colour slider in the CMS until it sits on the reference line or will I have to use the tint and brightness slider as well to achiever the correct setting which could get somewhat confusing?

Thanks
jeansibelius24 is offline  
post #42 of 44 Old 06-29-2012, 08:15 AM
Member
 
dominickwok's Avatar
 
Join Date: Jul 2009
Posts: 188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by jeansibelius24 View Post

I just wondered if I do a sweep of the primary and secondary saturation levels do I use the saturation luminance graph in HCFR and try and get each as flat as possible.

DON't use the Saturation-luminance graph in HCFR - it has serious bug there and it presents you a totally wrong graph. The problem lies in that it 'normalizes" all the color luminance curves in such a way that it 'assumes' the measured luminance at the 100% saturation level is perfectly correct and then plot the data points for 0%, 25%, 50%, and 75% as relative error to the 100% data point. So if your luminance of Red at 100% saturation level is +10% off from the standard, and you try to 'level' the luminance curve for the other 4 saturation points, you will end up with +10% luminance error for all the saturation levels (even though the HCFR graph will tell you "a perfect alignment with standard").
Quote:
Originally Posted by jeansibelius24 View Post

If yes do I go through each saturation pattern from 10-100% and adjust the colour slider in the CMS until it sits on the reference line or will I have to use the tint and brightness slider as well to achiever the correct setting which could get somewhat confusing?
Thanks

From my reading on your message above, it appears that you might get the concept wrong with respect to calibrating grayscale vs. color gamut using the controls in AE4000.

First of all, saturation patterns in the AVSHD709 disc consists of 30 patterns (no matter window or full field) - satruation level of 0%, 25%, 50%, 75%, 100% (5 patterns) x RGBCMY (6 colors) = 30 patterns. These are used for calibrating the color gamut using AE4000's Color Management System's "RGBCMY mode" (so that's where located the individual Color, Tint, Brightness sliders for R, G, B, C, M, Y). There is no saturation pattern namely "from 10-100%". The only set of patterns that you measure for 10-100% is the grayscale patterns (actually from 0% black to 100% white), in which you use Red / Green / Blue Contrast sliders to adjust the high end of your grayscale, and Red / Green / Blue Brightness sliders to adjust the low end (these slides are those located just at the top of the Advanced Menu, nothing to do with the controls in Color Management), so that your white point for 10%, 20%, ..., 100% stimilus level sits closely to the D65 point. The concept of "grayscale" (or white balance / white point) has nothing to do with the color gamut (although the controls for adjusing grayscale and the controls for adjusting gamut may, and likely will, interact / interfere with each other).

I suggest you first get familiar with the difference between grayscale and color gamut before you mess up your AE4000 settings. It seems that you use the adjustment controls for the wrong purpose. The following posts will help:

http://www.curtpalme.com/forum/viewtopic.php?t=10457

http://www.avsforum.com/t/852536/basic-guide-to-color-calibration-using-a-cms-updated-and-enhanced

http://www.avsforum.com/t/1134710/epson-calibration-guide-1080-1080ub-6100-6500ub-7500ub#post_16166537
(AE4000 behaves very similar to these Epson models with respect to CMS behaviour)
dominickwok is offline  
post #43 of 44 Old 06-29-2012, 10:18 AM
AVS Special Member
 
HDTVChallenged's Avatar
 
Join Date: Jan 2002
Posts: 8,383
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 132
Quote:
Originally Posted by dominickwok View Post

DON't use the Saturation-luminance graph in HCFR - it has serious bug there and it presents you a totally wrong graph. The problem lies in that it 'normalizes" all the color luminance curves in such a way that it 'assumes' the measured luminance at the 100% saturation level is perfectly correct and then plot the data points for 0%, 25%, 50%, and 75% as relative error to the 100% data point. So if your luminance of Red at 100% saturation level is +10% off from the standard, and you try to 'level' the luminance curve for the other 4 saturation points, you will end up with +10% luminance error for all the saturation levels (even though the HCFR graph will tell you "a perfect alignment with standard").

It's not a "bug" it's a feature. smile.gif Seriously, as far as I can tell it was just meant to show how much the saturations are drifting wrt to the 100% points. But you are correct in that it shouldn't be used for any other purpose.

Also, be wary of the primary/secondary Delta Luma's ... these *are* referenced to the "standard," but in most cases you'll probably want use targets "normalized" to the primaries you actually have, not the ones you wish you had. smile.gif
HDTVChallenged is offline  
post #44 of 44 Old 06-29-2012, 12:51 PM - Thread Starter
Member
 
jeansibelius24's Avatar
 
Join Date: May 2012
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Sorry my previous post was a bit confused. I was aware that the saturation levels go 0% then 25% etc and the greyscale goes from 10-100IRE%. The problem I am faced with is that when trying to do the Stereomandan’s 75% saturation method I cannot get the RGB level bars to the correct percentages. I just wondered if there was an alternative method I could possibly try.

I have read and followed those guides that you recommended but I will re-read them as there is alot of information to take in.

Thanks for your help.
jeansibelius24 is offline  
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