Setting Blueray player before TV calibration question (IRE over HDMI).

Varios calibration documentation on many websites talk about first setting your "player" correctly before beginning calibration of the TV.

One area I am stuck on is IRE setting on a Blueray player (in my case the BD30) of either 0 or 7.5 DEPENDANT ON CONNECTION METHOD.

From HOME THREATERMAG...

When troubleshooting brightness for information below black, you can adjust the player's IRE. If there's a choice between 0 and 7.5 go with 0. On some sets this is called DARK for 0 and LIGHT for 7.5. Only have to adjust if you cannot get the drop shadow on the THX Optimization pattern on the DVD to appear when the brightness is turned all the way up. Setting IRE to 0 io so that "Below Black" is being sent to your TV. Otherwise the drop shadow sometimes cannot be displayed and Brightness settings cannot properly be made. This is echoed to some degree in THX's own documentation.

Avical's DVE User-Level tutorial at avical.com and Preparing the DVD p[layer for calibration before starting...

"If there is a black-level control and the composite or S-video output is being used, place it in the 7.5 IRE position (LIGHT). If component is being used, place it in the "0" IRE position (DARK)."

And lastly from Panasonics OWN manual for the BD30 BD Player on page 20...

"Black Level Control
Select lighter or darker for adjusting the black level control to the
desired setting for picture enhancement.
≥Lighter: When video is output from VIDEO OUT or S VIDEO OUT
terminal.
≥Darker: When video is output from COMPONENT VIDEO OUT
terminal."

So. You can see a common thread here. If component, set to DARK (0 IRE) and if composite or s-video, set it to LIGHT (7.5 IRE).

Any comments on this from seasoned calibrators is welcomed but more importantly, and the reason I post this is this...

What about when over HDMI!? No one talks about this IRE setting over HDMI. Anyone know the correct setting of IRE for HDMI output from your DVD or BD Player?

I am playing with calibration and I am perplexed by this one.

*EDIT* Here is more I have stumbled upon...

Oh and then I have found this... http://www.avsforum.com/avs-vb/showt...89#post4969789

Guess I have more reading to do. But at least the answer (upon a fast read through) appears to be in there.

C.

Thank you everyone. I will check to see if the darkness setting has any effect on blueray output over my HDMI. That should help.

But just off hand...

At the BD30's MFG's default setting of LIGHT (7.5), and running the Blueray version of DVE HD basics, the greyscale ramp does indeed show all the steps distinctly when I lower the contrast from 100 down to about 80 or so. Also, even at 100 on contrast the THX white crush pattern (6 squares or something or other) does not crush no matter what and whitest squares remain white to the eye even at 100 contrast.

I'll get back to everyone once I can try light versus dark on the BD30. But that said, in the owners thread I get alot of "leave it at light or you'll crush blacks" comments. But no one has actually addressed this as an "official IRE over HDMI best practice" type question.

C.

Not sure if this is still accurate or not but...

Well, this post may not be 100% perfect scientific way to explain all this, but given the alternate, images really would help. Lots of jibber-jabber and jargon only goes so far. I'm simply amazed at how confounding video information has to be. What should be basic principles of video (think "atoms have protons, electrons and neutrons") seemingly require advanced degrees in video theory. Uggh. Anyway, here goes an attempt to convey knowledge to the layman....

- DVD MPEG is IRE 0.0
- IRE is the name of the group that set the standard
- 0.0 is the "total black" side of the scale. It goes to "total white" at 100.0.
- North America (will call it "USA" for purpose of this article) has black set at 7.5 and not 0.0. Blame lazy engineers from a long time ago. Because of this, all of our equipment is different from Japanese stuff. Or at least is SUPPOSED to be different.
- When a NTSC USA player gets a DVD, it's output is stepped up +7.5 IRE so the tv understands it and it looks correct. When an analog signal (VHS, cable, tv, etc) is inputted into a digital device, the device steps down the IRE by -7.5 so it is at proper 0.0 for digital needs (playback, capture, encode, etc).

SOURCE...

http://forum.videohelp.com/topic259098.html

Not even sure if I have answered this yet or not. But that was interresting but a few years old now.

Oh and then I have found this... http://www.avsforum.com/avs-vb/showt...89#post4969789

Guess I have more reading to do. But at least the answer (upon a fast read through) appears to be in there.

C.

Fantastic response. Thanks.

They also meantion much of what oyu have just said here taken from that link I posted...

"2) For DVD players when using a digital output (DVI, HDMI).

When using digital outputs, your primary concern is to get the DVD’s image data output as undisturbed as possible. As simple as this might seem, design/price constraints, sloppy engineering, and ‘features’ can get in the way of transferring the digital data from the DVD intact. Always try to avoid using any image-altering features such as picture controls. These adjustments will usually have negative impacts on picture quality.

When using digital outputs, the major adjustment option you have is the one for digital levels. As is common in consumer labeling, the labels for this can be confusing. The most common labeling will at least hopefully show that you are making an adjustment to the DVI/HDMI digital outputs, and usually the options will read ‘Normal/Enhanced’ or ‘Normal/Expanded’ or ‘Video/PC,’ or some such label. The last pair of labels is clearer, as this adjustment is choosing whether or not the digital image data is correctly output using Studio (also called Video) levels, or is incorrectly re-mapped to PC levels. You should choose to maintain Studio levels by checking to make sure this option is properly set, usually by selecting the equivalent of "video" or "normal." Usually the default setting will correctly choose the option for Studio levels, but not always. Check to make sure....

Because you are using digital outputs, adjustments for analog outputs shouldn’t be a consideration. Unfortunately again, due to cost-saving designs sometimes analog output adjustments, such as those for IRE setup, are implemented digitally even though they have nothing to do with digital outputs. Here your concern is still to ensure that the digital image data is being left as undisturbed as possible. In a well-designed player, the IRE option will have no effect whatsoever when using digital outputs. If this setting causes any change in the image when using the digital outputs, you should use test patterns to see which option leaves data un-clipped. In this instance, the degree of clipping or image alterations may be severe, so Avia, DVE, or any good test disc will come in handy. In Avia, look for the moving near-black and near-white white bars; in DVE use the ramps (Title12:Chp14) and check for clipping (if you have access to Avia PRO, the Deep Ramps are excellent tests!). Use the IRE setup setting that maintains as much data as possible through to your display. The default setting may more likely be the preferred setting. Default is usually the 7.5IRE setting. This was reported to be the case on the Denon 3910; users should test this on their players and share model-specific observations to aid others!
With the hope that digital levels and IRE are conceptually disentangled, you should understand that the IRE setup option is really for the analog output, and shouldn’t have to be discussed when using digital outputs. Unfortunately, instead of implementing these analog adjustments in the analog domain, cost-conscious designs seem to be altering the digital values, which necessitates double-checking this option to make sure your digital levels are not being tampered with."

I am far from a guru on this stuff. This place is loaded with them. But a question I would have for you is about the pattern you are talking about....

Reverse grey scale ramp? The one for the Contrast?

On my PZ85 and BD30 with that blueray I CAN in fact get the last two brightest bars in the ramp to show separated or nor clipped" by lowering my contrast. So ya. You CAN actually get the second last aquares to be shown as separate. Well the black is a hard one to see but the white for sure. At least as I play around with mine.

But regarding the IRE, I think that effects black levels more as far as I know. If you are clipping below 100% black, the third bars from the middle closest to the edge of the screen or "outter darkest bars" are below black and when you increase BIRGHTNESS all the way up you should be able to see them. If you do, then you are not clipping black and running BTB signals to the TV. As for the white, I am not sure.

Check this document out...

http://www.avical.com/articles/avica..._tutorial.html

They explain all this better than I do.

I am now playing with the Getgray DVD and I am finding that as far as contast goes, THX Optimizer and Getgray are both happy with my set at 100% contrast and their patters show NO clipping whereas with DVE HD Basics does not pull the 2 brightest bars in the reverse greyscale out of clip until I drop under 80% Contrast so perhaps it's to do with the DVE?

Check a Starwars or Indiana Jones disk for the THX Optimizer tool in the options menu and they have a patter where there are 8 squares and if you can't un crush em (make em all distinct) by lowering contrast there may be something wrong with your setup.

Does your receiver have a 100% passthrough option? Then it should not be messing with the signal.

C.