Hi Guys,
This forum has been extremely helpful in the past with my home theater receiver calibration. I recently bought a Samsung LN40A650 a couple of days ago and then looked at one of threads here, which directed to Curt Palme's guid to calibration.

I had the AVIA DVD that I used for my home theater calibration and I bought a Spyder2express as recommended by the guide.

I was able to somehow adjust the the grey scale and the adjusted luminance curve fell on the target curve. I used CHCFR software.

However, I was not clear on a few things.

1. Contrast
I put the 100 IRE window and adjusted contrast and the guide tells to adjust constrast looking for 30-40ftl. When I did that, the image looked very dull. On further researching on the web, I found that for LCD's, the recommended value is between 50-60. What is the value for this?
2. Brightness
I followed the guide, which says the following

* Set the contrast as in the previous section and record the Y value (light output) on the 100 IRE window pattern.
* (Spyder2 users only) Increase the sensor read time temporarily to 2000ms by going in the "Measures -> Sensor -> Configure" option.
* Display the 10 IRE window pattern.
* Adjust the brightness so that the Y reading of the 10 IRE window pattern measures as close as possible to 0.65% of the Y reading of the 100 IRE white pattern. For example: At 100 IRE we measured a Y value of 47.387. 0.65% of this is 47.387 x 0.0065, or a Y value of 0.308. We would therefore adjust the brightness until the Y value reads 0.308.
* This sets your gamma at 2.2 for the the 10 IRE window pattern which is typically the perfect gamma value as explained previously. In most cases this will be the correct setting for brightness. If your display has an unusually high or low gamma or a non-linear gamma, this method may give you the wrong result such that you can't see the 2% or 4% PLUGE bars (black clipping) or the black background is far too grey. In that case, adjust the brightness setting using the traditional method described previously using the PLUGE pattern.
3. GreyScale
It recommended that I display 80IRE and adjust the RGB HighEnd till the x=0.313 and y=0.329. It then recommends to use 30IRE and adjust RGB LowEnd till x=0.313 and y=0.329

On my samsung, I did this on white balance section which has RGB OFFSET and RGB GAIN. the manual tells that RGB OFFSET is for dark side and RGB GAIN for bright side. Have I done this correctly?

After this, I used the Grey Scale measurement from 0 IRE to 100 IRE. The graph was still not falling on the target line and hene kept adjusting the gamma and when I set gamma to -3, the grey scale looked perfect.
4. Primary and Secondary color
The guide says
# Cue up your AVS HD 709 test disc and skip to the 100% white window pattern by selecting "10% Grayscale" -> "100% Gray window". 100% means that the window is at 100 IRE. Write down the Y (Luminance or brightness) reading as seen by the sensor:
# Skip to the 100% Red window pattern by selecting "100% Saturated Colors" -> "100% Red window".
# Adjust the colour control on your display until the Y reading is 21% of the 100% white window reading measured earlier. For example, if the Y value earlier was 39.012 as seen above, then 21% would be 39.012 x 0.21 = 8.193.

I did that and I followed a similar procedure for Tint which called for using a 100% Cyan window and set it until The SDTV - REC 601 (NTSC) cyan target is x=0.231 / y=0.326 . Here, I was never able to set it to this number, no matter what I did. What am I doing wrong here?

Finally it said to measure the color values for RGBCMYW and adjust them individually for the standard values. Samsung has Color space and I can only adjust this if I pick Custom Color Space and when I do that, I have one line where i can pick one of RGBCMY and below that is three sliders for R,G and B. How do I adjust these sliders for the standard values. I adjust them randomly till the X and Y were standard values and the color was horrible.

I would really appreciate if you could help me with this calibration.
Also, when I watch the HD channels, they look great. But, the non-HD channels are very pixelated. And, when we watch a movie on these channels, my wife keeps telling me that the image doesn't look like movie, instead it looks very artificial/ like soap serials.

Again, sorry for this really long posting and hope that you awesome guys will help me out with this calibration.

Thanks a bunch in advance,
Vishwa

Your issue with measuring Cyan could be from using the Rec 601 target, while the AVS disc has Rec 709 patterns. There are differences in the two specifications for primaries and secondaries and their associated luminances, and you need to be using the Rec 709 targets with Rec 709 patterns. Also, AFAIK, tristimulus colorimeters like the Spyder aren't really recommended for CMS adjustments. For grayscale adjustments, they're OK.

Unfortunately, you've found one of the dirty little secrets of big-screen TVs: SD material looks like crap in many cases. Image flaws that you'd not see on a 27- or 32-inch SD set are suddenly magnified by the larger screen size. Plus, the scalers in many sets haven't really been that good, sometimes creating their own image problems when scaling, although this has been improving the last few years. If your set's gamma control isn't global (call it up while watching SD material and see if it's the same setting you had when using the AVS disc), then you can use it along with the contrast and brightness controls to add a little "pop" on SD images.

While I don't mean to criticize the instructions you received, I believe there are better ways of doing things, esp setting the contrast, gamma, and brightness. And I would go for 50-60 ft-l.
Are you calibrating in the user menu or service menu?
Contrast should be set by increasing the contrast until grayscale tracking goes south or until the gamma curve starts to flatten at the top end (white crush). Back it off just a bit below the white crush point (a couple clicks). Then adjust the backlight control until you get 50-60 ft-l.
Brightness should be calibrated with a test DVD or generator. You should be able to just barely see the pluge bars (2-4% brightness bars). You should not be able to see the blacker than black bars, and the black background should not light up.
Then adjust the gamma control to get 2.2-2.5 gamma, depending on if you have it in a bright living room (closer to 2.2) or a dark theater room (closer to 2.5). The Samsungs have gamma presets in the user and service menus. That may impact the grayscale, so there will be much back and forth adjustment.

I'd probably have one greyscale memory for 30-40ftL for viewing at night, and one greyscale memory for 50-60ftL for daytime viewing in a fully lit room. The greyscale on my Samsung LNT4661 does change as I increase or decrease the backlight, hence the separate greyscale settings.

I would find 50-60ftL way too bright for viewing at night in a dark room, not to mention that increasing the backlight has a noticably negative effect on black levels in a dark room.

HogPilot, you are absolutely right. Closer to 35-40 would be better in a dark room, and reducing it with the backlight is much better than reducing the contrast as those instructions suggested. One of the reasons I suggested 50-60, though, is that over the years of calibrating, I have found that wives really like bright pictures. My wife likes the improvement I make when calibrating, but she doesn't like when I have to reduce light output much. She thinks if I could do the calibration and leave the pic real bright it would be perfect. That seems to be a pretty typical reaction from significant others, and since Dagarshali mentioned his wife's comment, that might help him. :)

Yep, not disagreeing with your original suggestion, just offering some advice based on experience with my Sammy LCD and its black level limitations :)

I am always thankful that my fiancee is very forgiving about my HT proclivities (maybe obsession is more accurate). I've easily been through more displays (not to mention total equipment) since we've known eachother in the past 2 years than she has in her entire life. When I calibrated the Samsung she made the comment that it looked dim during the mid-day, which drove me to calibrate a 2nd greyscale setting with the backlight up to 5. But she also noticed the difference when I set it back to the darker backlight/greyscale calibration settings at night when we watched No Country For Old Men and seemed to prefer the lower black levels/more contrasty picture. As I said, she's very tolerant of my "fiddling" with stuff even when we're trying to watch a movie!

Hi Guys,
Thanks a lot for the response...

Chad, What exactly do you mean by this

Contrast should be set by increasing the contrast until grayscale tracking goes south or until the gamma curve starts to flatten at the top end (white crush). Back it off just a bit below the white crush point (a couple clicks). Then adjust the backlight control until you get 50-60 ft-l.

I also have this step grayscale pattern and when I try to increase the contrast, even at 100%, The white bars don't merge as so many online forums suggest. But, when I decrease the contrast, the entire thing becomes dull. So, how do i set it right?

I adjusted the brigtness the way you suggested using the blacker than black pluge pattern.

And the sammy that I have, I can adjust gamma only in steps of + or - 1.

Rolls-Royce
Your issue with measuring Cyan could be from using the Rec 601 target, while the AVS disc has Rec 709 patterns
I have the AVIA DVD that I bought like 4 years ago. How do I find which standard it has?

Thanks a lot in Advance

AVIA is SD (Rec 601).

The target values of secondaries like cyan are calculated from the color values of the primaries, so not only are you trying to match a 709 secondary to a 601 target, but chances are your primaries don't exactly match those of either standard, so the secondaries will be off as well. If you have a CMS that allows it, I suggest getting the primaries correct first, then adjusting the secondaries (the caveat against using the Spyder for this still applies, though). If you don't, there's a spreadsheet or calculator (I don't remember which right now) on the Accupel website that will accept input of your actual primary values and then will calculate secondary targets for you. Or switch to CalMAN calibration software, which allows you to specify custom color targets. Using this function will allow CalMAN to calculate your secondaries from the primary values it reads during this process.

Hi Royce,
I did look at the Accupel website and didn't find any calculator:(.
I am novice when it comes to all these. So pardon me if I asked a few dumb questions.

Am I calibrate for DVD separately and calibrate for the HD channels separately. I am little confused when you say that I am using 601 for a 709 target.

I also looked into the AVS disc that you mentioned in our response and if I understand correctly, it can only be played on a Blueray or HD dvd player. I just have the regular DVD player :(.

And, when you say CMS, I have a sammy 650 series and it has what is called a color space which has three options auto,native and custom. If I clicked the custom space, then I can choose any of rgbcym. the problem is for each of the color that i pick, there are RGB sliders that i can adjust. the question is do i adjust these rgb sliders randomly, for a particular color that i pick to achieve the x,y values according to standard. I am not sure if I am asking the question correctly. In order words, lets say I choose to set the red color, then i need to adjust the rgb sliders to get the standard x,y values. my question then would be that is the rgb values that i need to set for this color(RED) unique to get the standard or can there be various combination of rgb values for each of the color?

Thanks again..
vishwa

Hi Royce,
I did look at the Accupel website and didn't find any calculator:(.
I am novice when it comes to all these. So pardon me if I asked a few dumb questions.

Am I calibrate for DVD separately and calibrate for the HD channels separately. I am little confused when you say that I am using 601 for a 709 target.

I also looked into the AVS disc that you mentioned in our response and if I understand correctly, it can only be played on a Blueray or HD dvd player. I just have the regular DVD player :(.

And, when you say CMS, I have a sammy 650 series and it has what is called a color space which has three options auto,native and custom. If I clicked the custom space, then I can choose any of rgbcym. the problem is for each of the color that i pick, there are RGB sliders that i can adjust. the question is do i adjust these rgb sliders randomly, for a particular color that i pick to achieve the x,y values according to standard. I am not sure if I am asking the question correctly. In order words, lets say I choose to set the red color, then i need to adjust the rgb sliders to get the standard x,y values. my question then would be that is the rgb values that i need to set for this color(RED) unique to get the standard or can there be various combination of rgb values for each of the color?

Thanks again..
vishwa

Click on the link for HDG-4000 USB drivers on the Accupel site, and it will take you to a download page where you will find the calculator.

I'm sorry, but I misread your post and thought you were using the AVS disc, which has Rec 709 color patterns. You mentioned trying to adjust cyan to the 601 standard, which wouldn't work well with a 709 pattern.

If you want the best color, you'll need to adjust your primaries and secondaries to the standard you'll use. Each standard has a unique x,y coordinate for each color. Joe Kane Productions' website used to have a list of the different color spaces and their primaries, and it may still be posted.

Royce,
Thanks for you response. I still have a couple of questions regarding adjusting the color.

I have with me the x,y values for REC 601 standard for RGBCMY. So, in my samsung, I go to the custom color space and say I pick red to adjust. Now, I need to move the R,G and B sliders to get the right value of x,y for the color RED. I then need to go to each of the colors and adjust them individually. Am I right in understanding the procedure?

These are the standards that I have
R---0.6300---0.3400---0.2124
G---0.3100---0.5950---0.7011
B---0.1550---0.0700---0.0866
Y---0.4209---0.5067---0.9134
C---0.2306---0.3262---0.7876
M---0.3144---0.1606---0.2989
W---0.3127---0.3290---1.0

So, when i am adjust for red primary, I am moving the R,G and B sliders to get an x, y values of 0.63 and 0.34. my problem is can i move r,g and b sliders arbitrarily to obtain this value of x,y for red?

I did like that for all the colors and it looked like sephia picture...Don't know why.

Also, I am not sure if you have used CHCFR software. I need to tell that software, what standard i am using. The DVD player is set to output at 1080p and I still using AVIA disc. So, should I set the stand to 601 or 709 in the sofware?

Thanks a lot for being patient and helping me out..

Cheers,
vishwa

Royce,
Thanks for you response. I still have a couple of questions regarding adjusting the color.

I have with me the x,y values for REC 601 standard for RGBCMY. So, in my samsung, I go to the custom color space and say I pick red to adjust. Now, I need to move the R,G and B sliders to get the right value of x,y for the color RED. I then need to go to each of the colors and adjust them individually. Am I right in understanding the procedure?

These are the standards that I have
R---0.6300---0.3400---0.2124
G---0.3100---0.5950---0.7011
B---0.1550---0.0700---0.0866
Y---0.4209---0.5067---0.9134
C---0.2306---0.3262---0.7876
M---0.3144---0.1606---0.2989
W---0.3127---0.3290---1.0

So, when i am adjust for red primary, I am moving the R,G and B sliders to get an x, y values of 0.63 and 0.34. my problem is can i move r,g and b sliders arbitrarily to obtain this value of x,y for red?

I did like that for all the colors and it looked like sephia picture...Don't know why.

Also, I am not sure if you have used CHCFR software. I need to tell that software, what standard i am using. The DVD player is set to output at 1080p and I still using AVIA disc. So, should I set the stand to 601 or 709 in the sofware?

Thanks a lot for being patient and helping me out..

Cheers,
vishwa

OK, on the surface it looks to me like you are doing it right. But I've never worked with a CMS. May I suggest you read Tom Huffman's gude to color calibration with a CMS here on this forum, if you haven't already. It's the very first sticky at the top of the first page in this area.

The sepia picture could be due to the Spyder2. Some of the Spyders, including the two I owned, have been known to cause reddish grayscales. Again, many tristimulus colorimeters aren't recommended for CMS adjustments, although Tom does vouch for the GMB Display2.

I haven't used ColorHCFR software, but the other packages I've used do also need to be told what color space you are adjusting to.

As to whether your player is using Rec 601 or 709 when it upconverts SD DVDs, I don't know. I can only suggest that you search the DVD player area here for threads on your particular player and/or TV and see if there have been posts about this. Or contact the player and display manufacturers. Some players properly "twist" or convert the colorspace when upconverting DVDs, and some don't. And some displays will allow the user to select either Rec 709 or 601 decoding for 720 or 1080 sources. So it's good to know what both the player and the display are doing.:)