Calibrating for HD

[BrianC]

As I'll be picking up my new HD compatible set on Tuesday and getting Sky HD as soon as I can get an install date I'm keen to calibrate my set with a HD version of DVE as I had great success tuning my current (SD) CRT.

To this end I'm after some HD calibration screens for geometry, colour balance, and so on I can get. I'm not adverse to downloading them and running it from my PC to the screen.

Thanks in advance.

[sbowler]

Shouldnt the screen calibration be the same for SD as HD, cant see the difference, once calibrated for SD. What changes do you need to make for HD?

[BrianC]

I don't know either way, however I do know that I get slightly different results for PAL/NTSC material so I'm concerned the same might be true for HD material, but I'm a bit clueless when it comes to calibrating for HD.

[neilmcl]

Originally Posted by BrianC

I don't know either way, however I do know that I get slightly different results for PAL/NTSC material so I'm concerned the same might be true for HD material, but I'm a bit clueless when it comes to calibrating for HD.

The standard DVE disc will still apply to your HD screen.

[Stephen Neal]

Does the fact that HD and SD are based on different colourimetry make any difference to this?

[StooMonster]

You need different ISF calibration for SD and HD sources, e.g. greyscale is different on them.

Apparently there is an HD DVD version of DVE on it's way, and a BluRay one to follow too.

StooMonster

[BrianC]

But there is nothing I can use on my PC at the moment?

[hornydragon]

you can use nokia patterns, and even DVD but you will be calibrating to your PC's GFX card settings not your Sky HD box (there are some basic colour tests broadcast on Astra) same as with HD DVD/Blu-ray decks

Alot depends on your screen and how it handles HD (ie uses a new memory for each input signal)

[Tarbat]

As discussed previously, what we really need is for Sky or the BBC to broadcast a test card or series of test patterns for us to calibrate our TVs to the Sky+HD box. I understand that one of the broadcasters does this in the US.

[neilmcl]

Originally Posted by BrianC

But there is nothing I can use on my PC at the moment?

The HD version of DVE is currently a bundle only with DVE Pro. and is a Windows Media version only, so would be ideal for the PC but its quite expensive.

[Tarbat]

Originally Posted by cjgpers

I understand that one of the broadcasters does this in the US.

Hopefully the BBC or Sky will do what the American broadcaster HDNET does, and broadcast a test programme. This from their schedules:

Tue., May. 2nd - 6:50 AM ET
3:50 AM PT HDNet Test Patterns
Wonder how your home theatre is doing? Wish you had test patterns to help set it up? Well, HDNet is here to help. This short program will help you get the most out of your home theatre setup by providing you with the same professional test patterns HDNet uses to set their gear.

EDIT: Screenshots here - http://www.hdtvtotal.com/eng_hdtv_ga...s_0_p2243.html

[StooMonster]

Broadcast them? Why can't the STB simply have these test patterns built in? Wouldn't cost BSkyB any bandwidth then!

StooMonster

[Neil Davidson]

To clarify,

The greyscale target of D65 is identical for HDTV, NTSC and PAL.
The colour primaries and secondaries are different for HDTV, NTSC and PAL.
The perceived luminance is made up of different proportions of red green and blue for HDTV, NTSC and PAL.

The video procesor in the display has many different parameters that control how the input signal is translated for display on the screen. It would be incredibly difficult to design the processor to give uniform performance over every combination of input signals. Just have a look at the small list above - if you watch an NTSC movie on that nice new HDTV you have to convert from one colourspace to another never mind the scaling/deinterlacing that may be required! It is interesting to try changing between colour spaces using a paint package on the PC - the effect can be quite dramatic!

A top end display should allow a calibrator to set the greyscale, colour decoder and user settings not just per input but per input type (720P, 1080i, NTSC etc). Strangley this level of control is becoming common on Plasmas but not yet on LCD displays. Again if you have a set that supports this level of calibration the results should be truley outstanding - night and day compared to the factory defaults in fact.

Due to the huge variety of combinations there is really no substitute for a pattern generator when calibrating HDTVs. The casual user would need quite a few DVDs to get all the required patterns at all of the required resolutions!

If you do want to use a PC for calibration the best tool is Display Mate. This calculates patterns on the fly so can be used for any resolution display. Note though that you will still be a slave to the accuracy of your video card. My pattern generator gets a factory cal every 12 months to ensure it is accurate but what can you do about the DVI output on your PC?

HTH

Neil

PS - Not only should the patterns be built in to the STB in many cases they are! What we need is a Sky HD box hacking thread I think!!!