Spears & Munsil Blu-ray Test Disc

[Stacey Spears]

Finally, some questions. I will answer some of the questions and Don will answer others. Please don't be upset if it seems like I skipped your question. Don may not get to post until the weekend is over.

I am not entirely satisfied with DVE's explanation on how to use the SMPTE color bars...Does your disk included any sort of explanations on how you can use the green and red filters to improve your picture even further?

We had limited space, on-screen, for pop-up help, so we only discuss the blue filter basics. We, and by we I mean Don, have written more in-depth notes on the patterns. We have given the notes to the press as a starter. We will start publishing the notes as a series of articles on our site in the near future. We just need to get our site laid out to handle the amount of data we plan to publish.

Now, to get back to your question. The blue filter is normally used to set color and tint. The red and green filters are to verify that color decoding is correct, after you set color and tint with the blue filter.

My TV has 6 color adjustments for both saturation and hue, and I would expect I could use these to help fix the colors.

Can you provide the make and model? This controls [i]may[/] allow you to fix the color decoding or they may be there to adjust the gamut (color primaries) of the display.

The red and green filters may not work. The green filter is the best way to find out if color decoding is correct, but it is also the filter that has the least chance of actually working.

Lets assume for a moment that they actually worked. When looking through the red filter, you should see two pairs of red bars. If the bars are not perfectly matched, then you have an error. Through the green the four left bars should look identical or you have error. You would want to adjust the controls until you were able to match them.

Sometimes these controls are tied to a "mode" on the display. Sometimes there are adjustments in the service menu to correct them. Sometimes you can't fix them.

[Stacey Spears]

1) Can I order your disc from Canada on Amazon.com?

You can order the disc from Amazon and it will ship to Canada. It will be shipping from the US.

2) I looked on your site FAQ and you say that you do not supply any color filters. How then can I calibrate color? (... and if I need filters, can you recommend where I can purchase them on-line?)

The first thing you must understand is that filters are not 100% accurate. A blue filter, for example, may leak red and green. We have several filter sets that we are evaluating. Towards the end of April we plan to measure the spectral response of several display types (plasma, LCD, DLP, etc...) to help us find the most reliable filter. Once we have found a blue filter we are happy with, we hope to include it with the disc. I don't forsee us including a red or green filter. Not because we are cheap, but because they may never work. We could probably find a red that works in many cases, but I don't expect we will ever find a green filter that works.

The green filter that comes with DVE does not work with my current display, which is the Joe Kane Samsung SP-A800B. This display has a red, green and blue only mode, so filters are not necessary. When I compare the green filter with the green only mode, they are not even close. Green only shows perfect decoding. The green filter shows that is is way off.

Both the DVE and THX websites offer their filters for sale.

3) Do you discuss how to deal with the White Balance? The color calibration on the disc I have ignores it completely.

No. We tried to limit the content on this disc to adjustments that don't require special test equipment.

4) Are you familiar with the disc that I downloaded? (ITU-R BT.709 AVCHD) http://www.avsforum.com/avs-vb/showthread.php?t=948496
What would your disc do for me and my LCD that this free disc does not? (i.e. is it worth the $$?)

The AVS disc appears to have all of the patterns necessary for white balance. It has a couple of patterns for sharpness and resolution evaluation, at least for the luma channel. It also has patterns for clipping. They make me wish I would have used black text on our clipping patterns.

We have some motion video content. The 3-minute montage was shot on the RED ONE camera at 4096x2048 and downsampled to 1080p for BD. With the exception of dither to convert 16-bit down to 8-bit, its noise free. The montage is available with all three high quality audio choices: PCM, TrueHD and DTS-HD MA. The TrueHD has DialNorm set to -31, which is off. This is, I believe, the first time a disc has all three on equal grounds. I had to use 16-bit / 48 kHz audio because I pushed the video bitrate as high as possible. There are peaks that reach 50 Mbps, as reported by the PS3, during some of the dissolves.

We have the first truly accurate pattern to evaluate and set YC delay. Others have had patterns, but none like this. We have full range chroma patterns. In fact, it will show off just how good Panasonic's PHL Chroma processing is. We also have a nice pattern for sharpness.

We have a full suit of deinterlacing tests in SD and HD. This will allow you to find out how good the deinterlacing is in your Blu-ray player for DVD sources and 1080i HD sources. If you have a source direct mode, you can also use it to evaluate a video processor or display.

Not all of the above is for everyone. Setting the basic picture controls is the most important part. You might be covered by the AVS disc.

Here is a sample from the montage. I have posted a link to the original 16-bit 4k TIFF as well as the 1080p source frame and encoded/decoded frame so you can compare. I posted at full resolution. I hope this does not upset too many people.

Original 4k TIFF: (48 MB) http://www.spearsandmunsil.com/image...riginal_4k.tif

Source:


Encoded:

[Clark Kent]

Originally Posted by Stacey Spears

We have some motion video content. The 3-minute montage was shot on the RED ONE camera at 4096x2048 and downsampled to 1080p for BD. With the exception of dither to convert 16-bit down to 8-bit, its noise free. The montage is available with all three high quality audio choices: PCM, TrueHD and DTS-HD MA. The TrueHD has DialNorm set to -31, which is off. This is, I believe, the first time a disc has all three on equal grounds. I had to use 16-bit / 48 kHz audio because I pushed the video bitrate as high as possible. There are peaks that reach 50 Mbps, as reported by the PS3, during some of the dissolves.

That is very interesting. For the audio comparison, is the audio mix 5.1 or 7.1?

[Stacey Spears]

For the audio comparison, is the audio mix 5.1 or 7.1?

It is 5.1. The DTS trailer is available in 5.1 and 7.1. The TrueHD trailer is 7.1.

I encoded the audio. DTS has many 7.1 options. My understanding is that some of the software on the market has used various speaker layouts while the decoders only implemented one. This is why there are reported 7.1 problems. The decoder vendors should be able to fix by doing a little more work on their end.

[BluCheez]

Thanks, Stacey, for your detailed responce.

You mentioned that your disc doesn't come with tutorials like DVE. Do you include a PDF or some other documentation that explain to the user how to run all of the tests? For example, I have no idea what YC delay is.

You said that, "We have full range chroma patterns." By chroma do you mean color? If so, how can someone adjust for color if they do not have a filter or special equipment?

Last question (for now ). What should I do about White Balance. When I start calibrating color by adjusting the Hue and Color settings (if I ever get ahold of blue filter) should I have all my White Balance settings at 0 to start? The present WB settings I have came with an entire calibratoin that I borrowed from someone who posted it on a formum.

Thanks again!

[Stacey Spears]

Do you include a PDF or some other documentation

Here is the PDF that we currently have. This is included with the disc. http://www.spearsandmunsil.com/pdf/U..._Benchmark.pdf

The information is also available by pressing the up arrow while looking at a pattern. In addition, there is also a "good" and "bad" example with the on-screen help.

By chroma do you mean color?

Sorta. The video on the disc is stored in the YCbCr color space. By using a known equation, this data is converte back to RGB. The Y portion is B&W and where most of the detail lives. The Cb and Cr are the color difference signals. They are half the resolution of Y. DVE includes a chroma ZP as do we. The difference is DVEs started off as 10-bit 4:2:2 and we created our as native 8-bit 4:2:0. DVEs had to be converted to 8-bit 4:2:0 using filtering.

I realize (or is it realise ) that all of the above is techno babble. Normally when people measure resolution they look at only the Y channel. Now they can also look at the Cb and Cr channels.

The Panasonic 35/55 and new 60 series have better chroma resolution. They advertise it as PHL Chroma Processing. PHL is a facility in CA that does authoring and encoding for Blu-ray. They have their own AVC encoder and are often considered ahead of the game with AVC.

If you compare the Panasonic DMP-BD60 to the PS3 by looking at chroma resolution, you will find that the BD60 wipes the floor with the PS3. The 2nd row, last burst on our Chroma MB is nice a bright with the BD60. It is dim with the PS3, and most other players. This is your highest frequency horizontal resolution. You can see a similar effect with the chroma ZP. The left and right halves of the image are dimmer. This will translate into the finest chroma detail. It would probably only show up on something like an animation.

What should I do about White Balance.

White balance is done using a meter. There are a lot of inexpensive meters, but I am not sure how well they work. The Photoreasearch PR655 (or older 650) are known devices. This is about a $20k device that requires you to spend $1500 a year to have re-calibrated. This is where an ISF or THX calibrator comes in.

[Don Munsil]

Originally Posted by BluCheez

I have no idea what YC delay is.

Y/C delay is when the luma (Y) channel is not aligned properly with one or both chroma (C) channels. When it's bad, it shows up as colored fringes on both sides of objects on screen. When it's mild, it just makes the picture look less sharp. You have to put up a test pattern and get right up to the screen to see what the problem is.

In the pre-digital days the primary source of Y/C delay was analog processing delay in amplifiers, video processors, etc. If it look just a tiny bit longer to process the chroma channel than the luma channel (or vice-versa) then the chroma and luma signals wouldn't be aligned on screen. This kind of problem could only affect horizontal alignment. To shift vertically, the signal would need to be delayed a whole scan-line in time, which is huge. In practice that never really happened.

With digital compression, it's now possible for the chroma and luma to be misaligned vertically and horizontally. And in fact it happens fairly regularly. The most common case is when the MPEG decoder and/or color space converter take shortcuts and don't upconvert the chroma channel correctly. This usually results in a half-pixel shift in the chroma channel, which is hard to see but not invisible.

It's also possible to just have a bug in the chroma upconversion code that shifts chroma by one (or more) pixel up, down, left, and/or right. We've seen that as well. Amazingly enough, many of these consumer electronics and chipset companies don't have QA checks for things like chroma alignment, in part because there hasn't been a really workable test pattern to test chroma alignment until we created one for this disc.

Hope that answered your question.

[Don Munsil]

A few more notes about colored filters. Since a filter may work OK with one display, but not with another, it's important to check how good the filters are before trying to calibrate with them.

It's not actually essential to use a blue filter; a green or red filter would work fine in theory. What you want is to use a filter that lets through a single color channel and cuts out all of the other two.

If you have a set of filters from another disc, put up a color bar pattern and look through the blue filter. The red, green, and yellow bars should turn black. If you see any residual red, green, or yellow color, or the "black" bars are not the same brightness, then the filter is leaking and should not be used to calibrate that display. If you have a red filter, try that one. It should turn the blue, green, and cyan bars black. If they aren't fully black, then again that filter isn't going to work.

The green filter is almost guaranteed not to work. There is a very narrow range of frequencies that don't overlap with the blue and red primaries on most real-world displays, and a green notch filter that just covers those frequencies would be really expensive. And even then, it wouldn't be guaranteed to work on every display.

If you have some red-blue or red-cyan 3D glasses lying around, the red side may work OK as a red filter, depending on the specific glasses you have. If you have the glasses that were used for the Super Bowl and for the Chuck 3D episode (which are called ColorCode and are Blue-Amber colored), the blue side is actually about as good as the THX glasses. Try them and see.

There are actually ColorCode glasses bound into this month's Fortune magazine, and in last week's Entertainment Weekly, People and Time, so that's an option for some low-cost filters.

One last thing to try. If you have access to more than one blue filter (like two pair of ColorCode glasses), try stacking two of the same color filters. The image will get very dark, but the frequency selectivity goes up, and if you can get them to the point where the bars that are supposed to be black turn black, then they're usable for calibration.

It's also worth noting that if your display has a "blue-only" mode, or a way to turn on and off color channels in the service menu, then that is absolutely the way to go. You may want to search "[display model] service mode" (and insert the actual name/model# of your display) and see if someone has posted the instructions.

Even if your display doesn't have a single-color-channel mode, you may be able to turn the gain down to 0 on two channels temporarily. If you do this, write down the starting numbers. You may think you'll remember them, but write them down anyway. I speak from painful experience.

[Don Munsil]

One easy way to get ColorCode glasses is to sign up for the ColorCode demo, here:

http://www.colorcode3d.com/servicepr..._cc3d_demo.htm

They'll give you a link to some ColorCode demo pictures and movies, and will also mail you two sets of glasses. A pair of ColorCode glasses' blue side, stacked, is right up there with the best blue filters you can get.

[johaen]

Originally Posted by Stacey Spears

Can you provide the make and model?

Sharp AQUOS LC-42D64U.

Originally Posted by Stacey Spears

Lets assume for a moment that they actually worked. When looking through the red filter, you should see two pairs of red bars. If the bars are not perfectly matched, then you have an error. Through the green the four left bars should look identical or you have error. You would want to adjust the controls until you were able to match them.

Here's some pictures of what I'm seeing.

Here's the original color bars, without any filter.


Here's with the blue filter:


Red:


Green:


As you can see, blue and red look pretty good. The problem is with the green one. It's like there's green in the blue and magenta bars when there shouldn't be, and there's not enough green in the green and yellow bars. I'm not sure if this is something that is at all fixable. I was able to get the green bar a little better by increasing the green in the saturation menu. The yellow I was able to get a little closer using the Hue option. I moved yellow a couple notches closer to green (and away from red), but this of course lowered the red in the yellow bar, which I could see through the filter.

I hope all that makes sense. That alot of color talk.

[Stacey Spears]

The problem is with the green one...I'm not sure if this is something that is at all fixable.

As Don pointed out above, the green filter does not work. Based on the red and blue photos you provided, I believe you are getting the proper color decoding.

[BluCheez]

Originally Posted by Don Munsil

One easy way to get ColorCode glasses is to sign up for the ColorCode demo, here:

http://www.colorcode3d.com/servicepr..._cc3d_demo.htm

They'll give you a link to some ColorCode demo pictures and movies, and will also mail you two sets of glasses. A pair of ColorCode glasses' blue side, stacked, is right up there with the best blue filters you can get.

Thanks! I filled out the e-form. Hopefully they will mail to Canada. In the mean time I have been exploring the Service Menu of my Sony 46" XBR4. It is all very cryptic, but I have been making some headway by doing some research. I haven't found a clear set of instructions for "blue-only mode", but it looks like the red and green can be adjusted from the SM. Question: it seems that I have two options for turning off the red and green. 1) Turn off the "red gun" and "green gun" (ROFF, GOFF on the SM); 2) Dial down the red or green (R-YR, R-YB for red and G-YG, G-YB for green). Which would be better? I'm justifiably intimidated by the SM. I don't want to get stuck (or worse). One thought that came to mind is that if I turn off the green gun, then I won't be able to see the green words and numbers that make up the SM. Then I'm screwed!

Let me be clear. I don't know much about the SM without clear instructions. I have successfully entered the SM and tweaked a few settings, but like I said this came with pretty direct instructions. The codes above I got from http://myweb.accessus.net/~090/sonyadj.html#xbr, but I'm not even sure if they are the same codes on my TV or how to navigate to them. The instructions on this web page are unclear.

Any help here would be appreciated.

[Don Munsil]

Originally Posted by BluCheez

Question: it seems that I have two options for turning off the red and green. 1) Turn off the "red gun" and "green gun" (ROFF, GOFF on the SM); 2) Dial down the red or green (R-YR, R-YB for red and G-YG, G-YB for green). Which would be better?

Turning the gun off would be better. If you want to experiment, I'd put up a color bar pattern, then turn off and back on the blue gun to see what happens. If that works fine, then try the red gun and only then maybe try the green gun. It's possible that when the green gun is off you'd have to turn it back on "blind" and that would be a pain. My guess is that it doesn't turn it off, it just cuts off the signal coming from the video decoder. So the on-screen display would be preserved. But I don't know for sure, so I'd make sure I knew the key presses to turn the gun back on before turning it off.

If cutting off the green gun also cuts off the service display, I'd just turn off the blue and red guns and use the green gun for calibrating. There's nothing magic about using the blue gun for calibrating color/tint. You can use any of the three channels. The specific bars that are visible changes depending on which gun is on, but the basic strategy is the same: make them all the same brightness.

And in general, before changing anything in service mode write down the original setting. I know I emphasize this, but it can't be emphasized enough. There is very little you can do in service mode that will permanently affect your display as long as you know what the factory setting is, so you can set it back if you get stuck.

And in general, don't fiddle with settings unless you know what the setting is supposed to do. The ROFF, GOFF, BOFF settings are pretty clear and understandable, and only have two settings: 1 and 0.

[Don Munsil]

I wanted to mention a few other ways to get a free or low-cost filter:

- Buy a pair (or two) THX optimizer glasses. They're $2 each + $2.50 shipping in the US.

http://www.costore.com/THX/producten...=87&pid=930793

- Buy two pair of ColorCode glasses at Berezin, for $3 + about $3.50 shipping (via USPS).

http://www.berezin.com/3d/3dglasses.htm#Colorcode

- Get a pair of free 3D glasses from Rainbow Symphony, here:

http://www.rainbowsymphony.com/freestuff.html

You might want to email them and ask if they'll send you a set of THX Optimizer glasses as part of the deal, since they are the company that makes them. If not, then get their red/blue glasses. The blue side is only so-so, but the red side isn't too bad.

- Go to your nearest theatrical supply and get a Lee filter swatchbook. Usually they just give them away, but if they charge it should be less than $3. Tell them you're putting on an amateur play. If they don't carry Lee, get a Roscolux swatchbook. The best blue filter for Lee is 71 - Tokyo Blue. For Roscolux it's 382 - Congo Blue.

As mentioned above, when dealing with any filter of any kind (including the THX filters), first check that the bars that are supposed to be black are in fact black. If they're distinguishable from the background, don't use the filters. But do try two layers of filter first; that might do the trick. Or if you're using a swatchbook, try looking through both Tokyo/Congo Blue and any other nearby dark blue.

If the bars that are supposed to be black are black, then the filters are fine, whether they came from THX or from your copy of "3D X-Men Comics".

[BluCheez]

Originally Posted by Don Munsil

And in general, before changing anything in service mode write down the original setting.

Thanks. There are a lot of settings. Do I need to only worry about the one that I am adjusting, or do I need to write them all down? I say this because it is possible that changing one setting might change other settings as well (i.e. without me even knowing about it).

[Don Munsil]

Originally Posted by BluCheez

Thanks. There are a lot of settings. Do I need to only worry about the one that I am adjusting, or do I need to write them all down? I say this because it is possible that changing one setting might change other settings as well (i.e. without me even knowing about it).

I hesitate to say this as a blanket rule, but it's not common for a change in one setting in a service menu to change other settings. Certainly I wouldn't expect changing a gun on/off setting to change anything else. If you really want to be sure, you could walk through the entire list of settings and write them all down, but I don't honestly think that's necessary. It might be useful just to be sure if you plan to try other setting changes.

[BluCheez]

Don, I scanned through all (there must have been over 2000) items in the in the SM. Unfortunately, I didn't see anything that looked like ROFF. It is possible that I just missed it (sigh...). So, either my TV doesn't have that setting, or I missed it, or I'm looking in the wrong place. There are 63 categories (and these contain from 1 to 1500 itemes). Do you have any idea where I should be looking or what the code might be for the guns? If not, how can I find out? I tried a Google search to no avail. I found a service manual at Servicemanuals.net for $15.99, but ordering the manual seems a little hard core! I just want to do some color calibration and I don't have a filter.

This is getting too complicated... I'll probably just try to get my hands on a filter (you gave me multiple choices). Would it be worth it to get the manual? I.e. would I find what I am looking for or would I need to have gone to "calibration school" to be able to interpret it.

Ahhh the joys of being obsessive about your TV!

[Don Munsil]

Originally Posted by BluCheez

Don, I scanned through all (there must have been over 2000) items in the in the SM. Unfortunately, I didn't see anything that looked like ROFF.

Aha, sorry, I thought you knew your TV had the ROFF, GOFF, BOFF settings. On some Sony's there is an RGBS setting, which ranges from 0-7, with 7 being all colors on, and 0 being all off. 1 is Blue, 2 is Green, and 4 is Red, with other numbers being various combinations. Both the ROFF and the RGBS settings were available on CRTs, but whether they've kept either of them for the LCD displays I don't know. My Sony projector doesn't have either.

Sadly the service manual (at least for Sony displays) is not much help as far as what the settings do. It will generally list them and what the factory settings for them are, and sometimes put some cryptic notes about them, but the exact meaning of each setting is not generally documented. I don't know specifically for your display, but I've had service manuals for three different Sonys, and they focused mainly on IDing physical parts and giving instructions for assembly/disassembly.

Sorry I don't have a better answer. I just don't know that display.

[johaen]

Originally Posted by Stacey Spears

As Don pointed out above, the green filter does not work. Based on the red and blue photos you provided, I believe you are getting the proper color decoding.

Thanks for the information. I'll just have to be happy with my current (awesome) picture quality.

[Don Munsil]

I just realized from a PM conversation with one of the members here that not everyone knows that our disc is being bundled with the forthcoming Oppo BDP-83 player in addition to being available separately now. Obviously, for those who are planning to buy that player, we're hoping you'll buy the disc now, then when the Oppo comes out you can give the spare copy to a friend or relative. It's the perfect gift for any occasion!

If you already have a Blu-ray player, you can get the jump on all those people who are still waiting for the Oppo player by getting your disc now! Don't delay! Operators are (probably) standing by!