CalMan 5 Release Notes and Discussion - Page 38

Originally Posted by eghill1125 

I gave it another shot and something just isn't working. To rehash.. I have the C3 meter and Calman 5 with my LG lw5600 LCD.

When I set the 2 point grayscale with 30-80%, I have no red in the 80% and only a small bit in the 30%. Blues are in the 112-15 range. My initial color temp readings are in the 8900-9000 range. Everything out there says the colors are really good on this tv and I believe they are. Just not sure why I have such a bad reading for temp and reds. They are basically missing through the whole 2 and 10 point grayscales. Turning contrast down has not helped at all. I have tried contrast from 94-72. The color clipping pattern with a contrast of 90 shows red stopping at 245 and green and blue at 247-249.. As everyon would figure, adding red in all the % points does nothing but kill the picture and I am left with nothing but pinks instead of whites..

Any ideas for me. I can get into the SM without a problem, but figured the controls are there without it, so I wouldn't yet.

The meter is brand new so I wouldn't think it is the problem..

Originally Posted by eghill1125 

That was in the Warm setting. The Medium was around 9700 and cool was over 10,000. Warm was 9069 last time i did it. I can understand why I have a ton of blue and no red then. Just no idea what I can do about it without raising the red to +50 and lowering Blue to -50. Then I have a nice shade of pink everywhere.. I believe I read before to leave Green alone if at all possible. I thought for sure that meant I was clipping red off, but the patterns don't show it and lowering contrast did not make a change on it either. Completely stumped right now.

Originally Posted by eghill1125 

I have done all those things already. I set the brightness, contrast, backlight to give me mid 50's for daytime and then on the 2 point, I ended up with deltas in the 1's for 30% and 80%. But what i meant is to do that, I had to add red to the max, lowered green to -25 or so and lowered blue to the max also. I could see right away that the LG menu had turned pink, but went ahead anyways. Did the 10 point. delta was 1.7? and my gamma ended around 2.26. The line had no dips or peaks at all. The CMS barely needed any adjustments because all were under 2. So my end stuff looked good on paper... but the picture is very pink. I have a calibrated Samsung here that ChadB did before and unfortunately, my calibration isn't even in the same country let alone city.

Originally Posted by PE06MCG 

However, I wonder why the Black Level control on my display continues to be called Brightness.
Surely this should be an obvious target for correctness, or is there a good reason for this apparent error in terminology?

Originally Posted by AVfile 

Brightness doesn't just raise the black level. It raises everything - imagine a constant value added to the entire curve. I suppose it was intended to adjust your TV to match the "brightness" of the room.

That is with a traditional display. I've seen some digital computer monitors do bizarre things with brightness and contrast controls.

Originally Posted by PE06MCG 

I am aware that it is vital to get 'blackness' correct because as you say it adjusts the range of the 'whiteness'. However, the purpose of the 'brightness' control is to set the 'blackness level' not to adjust 'whiteness'. There is a different Display control for adjusting 'whiteness'.

It would surprise me if the black level adjustment control in the Processing Equipment for video is still called Brightness.

If there is a good reason to keep it or something I am missing then I am prepared to learn but otherwise I am wondering why the insistence on correct terminology does not appear to include 'Brightness'?

Originally Posted by AVfile 

My point was, the name "brightness" is not completely untrue as it can make the image brighter. Forget about someone with training using the control correctly. You have to keep in mind how they marketed TVs to the masses, and what the average consumer saw when they messed around with the control. They see the image get brighter and think brighter = better. You and I use the control to set black level but it would not be very good marketing to call it a "blackness" control!

My question is, do we even need the control on digital displays?

Originally Posted by Charles Poynton 
This note was formerly called BLACK LEVEL and PICTURE, reflecting a time when I was engaged in a campaign to give these controls meaningful and sensible names. I'm sorry to report that I have abandoned that campaign; however, I continue my effort to educate users and system designers.

Originally Posted by Charles Poynton 
This note introduces the two main user adjustments of a video monitor, BRIGHTNESS and CONTRAST. I explain the effect that these controls have on picture reproduction, and I explain how to set them. This note applies to computer monitors, studio video monitors, and television receivers.

Unfortunately, the labels BRIGHTNESS and CONTRAST are misleading with respect to their functions: The control called BRIGHTNESS mainly affects reproduced contrast, and the control called CONTRAST ideally affects only brightness! The misleading labels have led to a great deal of confusion about how to set up a monitor for good reproduction.

[[This note dates from 1999. It applies to CRT displays. At 2010-06-03, I am working to update it to reflect modern displays, particularly LCDs.]]

Permission is granted for noncommercial redistribution of this document in its entirety, including this notice. The latest revision of this document is available at www.poynton.com/notes/brightness_and_contrast/

If you would like to print this document, I recommend that you obtain the PDF version of this note.

black icon This icon indicates the BRIGHTNESS control, more properly called BLACK LEVEL. It adds or subtracts an offset, or bias, into the red, green, and blue signals. This control should be adjusted so that black picture content displays as true black on your monitor. Misadjustment of this control is the most common problem of poor quality picture reproduction on computer monitors, video monitors, and television sets. Later in this document, I will explain how to set this control properly. The setting is somewhat dependent upon ambient light. Modern display equipment is sufficiently stable that frequent adjustment is unnecessary.


picture icon This icon indicates the CONTRAST control, preferably called PICTURE. It applies a scale factor (gain) to the red, green, and blue signals. It affects the luminance (proportional to intensity) that is reproduced for a full white input signal. Once BRIGHTNESS is set correctly, CONTRAST should be set for comfortable viewing brightness.


This note was formerly called BLACK LEVEL and PICTURE, reflecting a time when I was engaged in a campaign to give these controls meaningful and sensible names. I'm sorry to report that I have abandoned that campaign; however, I continue my effort to educate users and system designers.

LCD displays have controls labeled BRIGHTNESS and CONTRAST, but these controls have different functions than the like-named controls of a CRT display. In an LCD, the BRIGHTNESS control, or the control with that icon, typically alters the backlight luminance, thereby effecting control over what in a CRT would be adjusted by CONTRAST. The remainder of this note applies just to CRTs.

I will explain the controls with reference to Figures 1 through 4 below. In the graphs, the x-axis represents the video signal input to a monitor, and the y-axis shows the luminance produced at the face of the screen. The transfer function involves a nonlinear relationship from signal to light.

Contrast ratio is the ratio of luminance between the brightest white that can be produced and the darkest black that can be produced. Contrast ratio is a major determinant of perceived picture quality: If a picture has high contrast ratio, you will judge it to be sharper than a picture with lower contrast ratio, even if the lower contrast picture has substantially more measurable resolution.

To achieve good reproduced contrast ratio and good picture quality, it is important to set black level accurately. The most common problem with picture reproduction on video and computer monitors is misadjustment of black level. Figure 3 shows what happens if BRIGHTNESS is set too low. Figure 4 shows what happens if BRIGHTNESS is set too high.

Originally Posted by AVfile 

My point was, the name "brightness" is not completely untrue as it can make the image brighter. Forget about someone with training using the control correctly. You have to keep in mind how they marketed TVs to the masses, and what the average consumer saw when they messed around with the control. They see the image get brighter and think brighter = better. You and I use the control to set black level but it would not be very good marketing to call it a "blackness" control!

My question is, do we even need the control on digital displays?

Originally Posted by Charles Poynton 
however, I continue my effort to educate users

Originally Posted by PE06MCG 

Regarding its need, I have always thought that the Display's Black Level was a necessary adjustment of the Display before calibration.
On my TV (an LCD CCFL) it seems to adjust the backlight.

What are you suggesting?

Originally Posted by turbe 

it's not all lost..

Even with the incorrect label of "IRE" that many manufacturers still use today (which doesn't help), we can follow this:
for ControlCAL, I switched from using "IRE" which doesn't match the display's labels in its menus (which can, at times, add to a user's confusion and to my support load)


We Can Do It! One user at a time™




.

Originally Posted by PE06MCG 

Thanks for reply Doug,

So things are changing which is as it should be with any science.

However, I wonder why the Black Level control on my display continues to be called Brightness.
Surely this should be an obvious target for correctness, or is there a good reason for this apparent error in terminology?

Originally Posted by PE06MCG 

@Turbe

Sorry, posted my reply before I read your post.

Many thanks for the background on this.

I am tempted to say 'I rest my Case' but frankly the people with the power take no notice so it seems a lost cause.

Perhaps my previous comments about Science always moving on were a little misplaced.

Originally Posted by sotti 

Look at PC monitors, most of them don't have a black level control anymore (brighntess usually = backlight). There is no reason on gods green earth that you can't map 16 to off, at least for LCDs. It may still be necessary on plasmas, but for LCDs the full "off state" is well understood and easily mapped to the input signal.

Since the only thing you should use brightness for is setting level 16 correctly (not getting 17 correct, or trying to adjust a range of values, even though it does effect a range), it' simply not necessary for a correctly engineered display.

So it's not that adjusting black level isn't needed on today's displays, but that it in designing a display it's a superfluous control.

Originally Posted by PE06MCG 

When you say map 16 to off do you mean backlight to off?

Originally Posted by PE06MCG 

If so my higher Black Level when I change from say RGB to YCbCr will not be an issue if the backlight is switched off at 16 as you are suggesting?

Originally Posted by PE06MCG 

Currently I have used high contrast with the backlight used to set my max Y output at100% white..
(Please note my non use of 100% IRE).

Originally Posted by Doug Blackburn 

65+ years of doing it wrong is the only answer. It has been labeled wrong (so has Contrast) for so long, nobody has the guts to start doing it right.

Originally Posted by eghill1125 

Gamma at 2.18.docx 203k .docx file

Is it ever correct after a calibration to see pink in the grayscale and white clipping pattern. I have included my grayscale numbers from my calibration today. I do see a touch of pink in my LG menu and possibly a little in faces, but other than that, the TV looks real good and the blacks are excellent now. I only see the pink real bad now on patterns on the AVS709 disk, but don't see anything wrong on this grayscale. Any thoughts?

Originally Posted by RocShemp 

I've been interested in getting CalMan 5 but am not sure which version to get. I see they have a "Tutorial" version that's supposed to walk you through the program step-by-step. I think that's the one for me but am not sure if I'll regret it later and wish I'd've gone for one of the more expensive versions. How user friendly is CalMan for someone who's only experience with Calibration is just doing changes on user menu with discs like DVE, AVS 709, and Disney WOW?

Originally Posted by derekjsmith 

We do allow upgrades from version to version. In most cases it is just the difference in cost. So little to no risk starting out with Tutorial and waiting to move up later.

In fact nearly 50% of those that start with Tutorial move up with in 60 days.

Originally Posted by RocShemp 

Thanks. I didn't know that I could upgrade as I go along.