HOW-TO: Calibrating Display to Match HTPC Output - Page 7 - AVS Forum
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post #181 of 486 Old 06-28-2005, 09:59 AM
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DVI-PC is 0-255
DVI-Video is the desired 16-235

[EDIT] Someone else has to verify, but my understanding is that the 6412 follow the video standard of 16-235

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post #182 of 486 Old 06-28-2005, 10:25 AM
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When I look at my burned DVD directory structure it shows two top level folders - AUDIO_TS and VIDEO_TS. The audio_ts folder is empty, and the video_ts has the various .bup, .ifo and .vob files.

That sounds correct. It should work on a standalone DVD player with that structure.

James


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post #183 of 486 Old 06-28-2005, 11:18 AM
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It's odd yours starts at 15-15-15. Is that with FFDShow? NVIDIA Drivers? Also, what resolution? At 1280x720 on my 6800GT with the 67.66, 71.89, and 72.14 drivers, I get perfect tracking with grayscale in DVE and 3no's patterns. However, with a version of TheaterTek before 2.1.1, the grayscale isn't perfect smooth - a scaling artifact was introduced that didn't make grayscale perfect in the grayscale patterns. Man, are there a lot of variables or what? All I know is that with TheaterTek 2.1 on my 6800GT, I get perfect levels tracking as long as all brightness/contrast/saturation settings are left alone at zero.

Maxleung...6600 GT AGP, ffdShow, 67.20 drivers, TT 2.1.1, 1280 X 720.

I don't think the extra expansion down to 15-15-15 is doing any harm, and the final calibration is taking place on the display devices (InFocus 7210 and Optoma H-79), and the picture is just gorgeous. I was just curious as to why I couldn't lock right on to 16-16-16 using TT's brighnesss control. I have TT's brightness set to -2 to get 15-15-15, and if I go to -1 the values jump up to 18-18-18. I'll check the tracking on the rest of the values next chance I get...

Quote:
I assume you're using VMR9, since Overlay doesn't really let you take a screenshot.

But of course!...

Thanks, Maxleung!

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post #184 of 486 Old 07-05-2005, 03:14 PM
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I just posted regarding differences in calibration when using colorfacts vs AVIA and I guess this thread explains why! I don't have DVE only AVIA, so I'd like to use 3no's video to calibrate. As I understand it, just zero out all settings on desktop and software dvd player, adjust so 16 and lower blends in as black, and 235-237ish and up blend in as white. For gaming, I assume I'd adjust so 0 and 255 are distinct? Few other questions:

1. Can someone explain the YV12 vs YUV setting?
2. How do I use the Phillips Pattern Generator greyscale screens to adjust red/green/blue gain/offset balance? As in what is the procedure for adjusting gain/offset with the Phillips tool?
3. What gamma settings are optimal for PC/gaming?

Thanks cyberbri for starting this great guide!
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post #185 of 486 Old 07-05-2005, 03:36 PM - Thread Starter
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1. Can someone explain the YV12 vs YUV setting?

--> Ie., if you use FFDSHOW to resize, you have to have the video in YV12 to do so. So you have to either output directly into YV12 with your codec (ie., DScaler 5.0.0.6), or put a filter before resize to force a conversion from YUY2 to YV12. You might see these referred to as 4:2:2, 4:2:0, etc. It's very technical, if you need to do some research on it. But otherwise, just remember FFDSHOW resize runs in YV12, so you need to make sure it is fed YV12, and you should output YV12 from FFDSHOW so there is no conversion back to YUY2.


2. How do I use the Phillips Pattern Generator greyscale screens to adjust red/green/blue gain/offset balance? As in what is the procedure for adjusting gain/offset with the Phillips tool?

--> I used greyscale patterns to adjust the rgb gains/offsets to get proper color temp. Then I used the color/saturation User Menu control to tweak the r/g/b bar saturations.


I believe game consoles are the same as DVD players and TV - 16-235. Only PC works in 0-255. To do greyscale on my console inputs, I unplugged two of the component cables and just left luminance (greyscale) and tweaked color gains/offsets to get a good greyscale color temp. If you're using factory defaults, you can even do this (or turn off color saturation) and see how the different color temp settings (warm/cool) affect the greyscale.

Why using other people's TV settings is a
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post #186 of 486 Old 07-05-2005, 05:39 PM
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cyberbri, I believe I read somewhere that more recent FFDShow builds don't require a filter to force YV12 conversion. But, I could be wrong...
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post #187 of 486 Old 07-05-2005, 05:46 PM - Thread Starter
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That may be true, max. I haven't kept up with the new builds, as last year's versions serve me perfectly well, and I don't know of any speed improvements that would warrant an upgrade for me.

Why using other people's TV settings is a
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post #188 of 486 Old 07-05-2005, 07:21 PM
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Quote:
Originally Posted by cyberbri View Post


2. How do I use the Phillips Pattern Generator greyscale screens to adjust red/green/blue gain/offset balance? As in what is the procedure for adjusting gain/offset with the Phillips tool?

--> I used greyscale patterns to adjust the rgb gains/offsets to get proper color temp. Then I used the color/saturation User Menu control to tweak the r/g/b bar saturations.

Thanks Cyberbri,

I loaded up the Phillips app, Predefined Patterns, Grey Bars. It has a bunch of grey bars with different gradients and says Colour Scale 0 -100%. But I'm not sure when I'm looking for. I apologize if this was explained previously or somewhere else. Am I supposed to adjust the rgb gains/offsets so that something matches or look a certain way?

Also, for hue and saturation adjustments, I don't have any adjustments for this on my display for DVI input. I guess I have to use the settings in Zoomplayer or Theatertek to adjust this via AVIA?


I just finished calibrating for video vs PC with 3no's videos and colorfacts. I first took screenshots of 3no's videos and checked in paint what each settings is. I set 16 to blend into the background with everything under 16 and for contrast I set it so that 239 was still distinguishable from the white background. I saved this preset and then did the it again for 1-254 for my PC gaming. My display is set OTB for PC via DVI I guess as contrast and brightness is set to 50/51 (almost default). I then doubled checked this with colorfacts and Find Nemo's THX Optimizer and it seems to all agree.
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post #189 of 486 Old 07-06-2005, 10:09 AM
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Quote:
Originally Posted by lovingdvd View Post

I'm not sure I did this right. Here's a quick summary. I launched Nero 6 Express and choose the option to create a DVD based on "DVD-Video Files". It says to use this option to create high quality DVD-Video from DVD-Video structures on the hard drive.

On the next screen it told me to add the video files into the VIDEO_TS folder it created, so I dragged all the files from the zip into that folder. I then burned it and it said it was successful.

Since I'm not at home where my DVD layer is, I wanted to try and verify the patterns were on the DVD correctly. So I put the burned DVD back into my PC and it asked me whether I wanted to play it using Media Player or RealPlayer.

I first chose Media Player and it came up with an error that said it couldn't play the DVD and to check my settings in Control Panel/Display. Then I tried again using RealPlayer and it just sat there and would not play.

Does that sound like what you would expect, or did something not work with my burn process?

When I look at my burned DVD directory structure it shows two top level folders - AUDIO_TS and VIDEO_TS. The audio_ts folder is empty, and the video_ts has the various .bup, .ifo and .vob files.

Should that be the case where it just copies these files verbatium, or was it suppose to use those files to dynamically expand and write out other files?

Thanks!


Bump. Can someone please comment on the above quote (taken from this post I made a week or so ago)? I'm still trying to figure this out. Thanks.
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post #190 of 486 Old 07-06-2005, 10:24 AM - Thread Starter
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Quote:
Originally Posted by stoked
Thanks Cyberbri,

I loaded up the Phillips app, Predefined Patterns, Grey Bars. It has a bunch of grey bars with different gradients and says Colour Scale 0 -100%. But I'm not sure when I'm looking for. I apologize if this was explained previously or somewhere else. Am I supposed to adjust the rgb gains/offsets so that something matches or look a certain way?

Also, for hue and saturation adjustments, I don't have any adjustments for this on my display for DVI input. I guess I have to use the settings in Zoomplayer or Theatertek to adjust this via AVIA?


I just finished calibrating for video vs PC with 3no's videos and colorfacts. I first took screenshots of 3no's videos and checked in paint what each settings is. I set 16 to blend into the background with everything under 16 and for contrast I set it so that 239 was still distinguishable from the white background. I saved this preset and then did the it again for 1-254 for my PC gaming. My display is set OTB for PC via DVI I guess as contrast and brightness is set to 50/51 (almost default). I then doubled checked this with colorfacts and Find Nemo's THX Optimizer and it seems to all agree.


That all sounds good.

When you use r/g/b cuts/gains to adjust greyscale, you are trying to achieve a 6500K color temperature across each IRE or bar/section of the greyscale. So for example, if you move the blue cut up and down, you can see a blue tint go in and out of the greyscale. Many TVs come from the factory with a very cool (high) color temperature, because bluish whites look brighter. That's why many people say that when you get a new TV, it's best to set the color temp to warm to compensate.

If you look at the Color Bars.bmp I have in a zip folder attached to this message, you will see the 5. CRT Adjustments, with gradations of r/g/b and greyscale. If the high end of the color scales blend together, you may have your contrast (white level) and/or color saturation controls up too high. The other individual sections of CRT Adjustments (White, Red, Green, Blue) will show you steps in increments of 1~5, so you can check for proper delineation between steps. Note that if you are set to 16-235, you won't see the low end as you have blended 1-16 together.

Hopefully all of this looks fine on your display. If it looks really bad, you may have to work around it through your video card controls. DVD playback software may have the controls needed, but that only works for whatever it's playing, and won't affect the Phillips test patterns you are working with.

HTH - but it sounds like your display is probably set up fine.

 

color bars.zip 9.6982421875k . file

Why using other people's TV settings is a
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post #191 of 486 Old 07-06-2005, 10:45 AM
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Quote:
Originally Posted by lovingdvd View Post

Bump. Can someone please comment on the above quote (taken from this post I made a week or so ago)? I'm still trying to figure this out. Thanks.

When I created this tool, part of my testing was to see if it would work on a simple Sony DVD player as well as my HTPC. I copied the VIDEO_TS and AUDIO_TS folders to a blank DVD using a "create a data disk" type application (which had no clue that it was actually video) and the Sony accepted the resulting DVD without complaint. The WinXP file manager drag&drop may even work, but I haven't tried it.
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post #192 of 486 Old 07-06-2005, 12:00 PM
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Quote:
Originally Posted by cyberbri View Post

That all sounds good.

Hopefully all of this looks fine on your display. If it looks really bad, you may have to work around it through your video card controls. DVD playback software may have the controls needed, but that only works for whatever it's playing, and won't affect the Phillips test patterns you are working with.

HTH - but it sounds like your display is probably set up fine.

Thanks cyberbri,

I checked my settings and they seem to match your screenshot pretty well. I'll just leave my rgb gain/offsets at default and adjust hue/saturation in the playback software. Interesting note, I adjusted in TT, then adjusted in ZP using the Nvidia Codec Color adjustment. Went back to TT and it didn't seem to change my inital TT settings. I would have thought adjusting the codec adjustment would have also altered my TT settings.
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post #193 of 486 Old 07-12-2005, 04:40 PM
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How would you change the calibration (3no's) procedure when I'm trying to calibrate multiple sources to the SAME DVI display input?

For example, I've got a Hughes DirectTV receiver connected via DVI to my NEC 50" plasma and I'm just about to change my setup so both my HTPC and the receiver go through the same DVI switch. I can't make any changes to the receiver setup (beyond changing the DVI color space) so both the PC and receiver share the same input settings....

Any thoughts on which color space to leave the DVI plasma input in? I'm thinking 16-235 for all the devices involved here (seems a shame to toss out the extra information tho).

I presume its easiest to tweak the PCs output after tweaking the display for the receiver. How do I go about doing that? In WMP10? In Powerstrip? I'm running MCE2005....

Thanks
Jonathan

P.S. How can I force MCE2005/WMP10 to run in VMR9? e.g. what particular combination of checkboxes do I need in the advanced video menu in WMP10?

P.P.S. Also, how can I change the nvidia decoder properties? I can't seem to find a property for the filter anywhere...
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post #194 of 486 Old 07-17-2005, 09:28 AM
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No response for the last set of questions. Let me ask one thats more generally useful to more people

If I'm calibrating my DVI output using the test patterns posted earlier (basically trying to make sure that my PC is filling the 16-235 range correctly), whats the best choice for the displays DVI black setting? I can choose between both ("low" and "high" in my NEC's terminology), presumably mapping between 0 and 16. I can also choose between STB/DVD and PC for the DVI connection too - independently of the DVI black setting.

I guess I'm unsure of what the interactions between the PC's DVI output (which I presume is always going 0-255, regardless of what we're calibrating it to), and displays DVI input (does the DVI set to a black of 16 expand the 16 of the PC back to 0?).

Jonathan
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post #195 of 486 Old 07-17-2005, 01:00 PM
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1) Make sure the HTPC is outputting the proper levels (ie black at 16 white at 235).
2) Calibrate the display so that black is black and white is white, with the option to give yourself some extra room (I have my PJ calibrated so levels >235 are still distinguishable).

Theoretically then, you shouldn't have to calibrate between DVI devices, since they should all be sending out the same range.

See what an anamorphoscopic lens can do,
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post #196 of 486 Old 07-17-2005, 05:40 PM
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Quote:
Originally Posted by stanger89 View Post

1) Make sure the HTPC is outputting the proper levels (ie black at 16 white at 235).
2) Calibrate the display so that black is black and white is white, with the option to give yourself some extra room (I have my PJ calibrated so levels >235 are still distinguishable).

Theoretically then, you shouldn't have to calibrate between DVI devices, since they should all be sending out the same range.

I hadn't really thought that all the DVI devices (currently 2 but expanding...) would be outputting the "same" range - but I guess you're right. After all, they are just passing a digital signal Thats what happens when you've been calibrating analog signals from multiple sources for so long!

So I guess if I put EVERYTHING possible into the 16/235 range (including my STB, display and PC (through calibration)) then I'm happy (?).

Presumably if I calibrate my display using my PC/DVI, I'll get my STB calibrated for free too....

[sigh] calibration is easy, if slow (Ive even rented Colorfacts units before to do various devices). The whole black at 16 thing freaks me out!

Jonathan
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post #197 of 486 Old 07-17-2005, 08:03 PM
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Quote:
Originally Posted by jotter View Post

I hadn't really thought that all the DVI devices (currently 2 but expanding...) would be outputting the "same" range - but I guess you're right. After all, they are just passing a digital signal Thats what happens when you've been calibrating analog signals from multiple sources for so long!

That's definitely an "in theory" though. But there's a much better chance than with analog signals.

Quote:


So I guess if I put EVERYTHING possible into the 16/235 range (including my STB, display and PC (through calibration)) then I'm happy (?).

Yes, in theory everything (talking video equipment here) should output with reference black at 16, and peak white at 235.

Quote:


Presumably if I calibrate my display using my PC/DVI, I'll get my STB calibrated for free too....

In theory

Quote:


[sigh] calibration is easy, if slow (Ive even rented Colorfacts units before to do various devices). The whole black at 16 thing freaks me out!

Jonathan

Black = 16 is just the digital version of black = 7.5 IRE

Good luck.

See what an anamorphoscopic lens can do,
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post #198 of 486 Old 07-18-2005, 01:58 PM
 
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Black = 16 is just the digital version of black = 7.5 IRE

eek!

no, not quite, they aren't synonomous, they are different both conceptually and in practice. Whether a 7.5IRE setup pedestal is present or not may *seem* very similar to black being placed at 16 instead of at 0, but keep in mind that with digital signals there is really only one video standard, and that places black at 16 universally. When black is at 0, you should consider that a graphics standard, not a video standard. In analog domains, black can be placed legally at either 0IRE, or 7.5IRE, and both are video standards. Further, BOTH of these standards have the full potential to pass and correctly maintain data below black. Conversely, when using a digital graphics mode where black and white are mapped at 0 and 255, respectively, there is no ability to transmit any data outside these bounds, so BTB and peak white data is lost.

The end lesson: do not confuse analog standards, which may place black at 0IRE, or 7.5IRE, and still correctly transmit reference- quality video signals with no degredation, and digital standards, of which only one, with black at 16 and white at 235, is correct for reference-quality video. In an analog domain, with correctly designed equipment, there should be no end-difference whatsoever between using a 0IRE standard, or a 7.5IRE standard(adjusting calibrations between them of course). In the digital domain, there *absolutely* is a difference between using the graphics standard of 0-255 and the video standard of 16-235 (even when you re-calibrate between them).
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post #199 of 486 Old 07-18-2005, 03:10 PM
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Chris to the rescue!

See what an anamorphoscopic lens can do,
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post #200 of 486 Old 07-18-2005, 03:32 PM
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Hey Chris,

I'm curious as to what video cards and displays you're using that can generate, pass and accept the negative analog voltages that the BTB levels would be at with ref black @ 0 IRE? I'm not familiar with any video cards that can output negative analog voltages. (Or a display that can eat them?)
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post #201 of 486 Old 07-21-2005, 10:10 PM
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For anyone wanting to check the captured screen for the correct levels this looks like a good easy free tool. No insyall needed just unzip. I'm going to try it tonight.



Color Cop

I've seen the light... and its "White 255"!! (or is it 235?)
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post #202 of 486 Old 07-23-2005, 09:55 AM
 
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Any decent input should be able to handle BTB below 0mv.

Video cards often don't go below 0mv because of their power supply, but I think some do. No matter, however, as PC sources are following their own loose standard of 0-700mV, roughly, which corresponds to 0-255, so BTB is still a positive voltage. This is why I don't recommend scoping a PC output and trying to force it into a consumer-video standard output voltage range, as you can do a lot of damage. Better is just calibrating the display to that the PC is outputting.
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post #203 of 486 Old 07-23-2005, 01:17 PM
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Also there are a number of standards for analog voltage levels, each of which place black/white, at a little different place:
http://www.videoessentials.com/comvoltage.php

http://www.videoessentials.com/RGBVoltage.php

See what an anamorphoscopic lens can do,
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post #204 of 486 Old 07-24-2005, 07:56 AM
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"Better is just calibrating the display to that the PC is outputting."

problematic when used for multiple sources....



Jim White
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post #205 of 486 Old 07-24-2005, 09:23 AM
 
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Which is why we have individual input calibrations as well...

there are always compromises, but it is always safer to match the display to the source, than the other way around. It is a rare source that has ample, and high-quality adjustment range for its outputs, but every decent display should have plenty of range and quality adjustment to match most sources just fine.
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post #206 of 486 Old 07-24-2005, 04:14 PM
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So how does this work for television? Does my receiver use video levels? If so, then I would have to adjust my brightness/contrast to fit the 16-235 range as well correct?
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post #207 of 486 Old 07-25-2005, 04:11 AM
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Since many of us have multiple input sources: CableBox, DVDplayer, DVHS, HDTV-Card(MyHD), all of which (in my case) have "standard" component output, AND HTPC; AND some displays only have ONE calibration setup, it would seem impractical to match the display to the non-compliant HDTV and then have to readjust whenever switching to one of the other more-STANDARD video outputs from the other devices.... would it not?


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post #208 of 486 Old 07-25-2005, 08:43 AM
 
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AND some displays only have ONE calibration setup, it would seem impractical to match the display to the non-compliant HDTV and then have to readjust whenever switching to one of the other more-STANDARD video outputs from the other devices.... would it not?

Yes, it is impractical, which is why displays have calibrations for each input, or should to be user-friendly. If you are stuck with one global calibration and a lot of sources (say you're running things through a video-switcher), then you will have to explore ways to align the sources to identical output voltages, being careful to make sure you aren't degrading the source output in the process. Most sources will not allow you to adjust the output voltages aside from a crude adjustment between 0IRE and 7.5IRE output for black. As I've mentioned before, having all the sources using the same standard will get you close to having one calibration, but especially with consumer sources, precision varies so you may still need individual calibrations for each source for slight discrepancies.

For digital outputs, if the same standards are in use, the levels should be the same from any decent source, so you may not need to have individual calibrations.

Keep in mind that when you speak of "standard" the PC world is murky terrain, and when the standards are hit well, they are not usually consumer standards that they're after.
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post #209 of 486 Old 07-29-2005, 04:58 AM
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someone please help me understand RGB Gain and RGB Offset, how both work with each other, and how to calibrate each of them individually, im stuck at this point, i use a dvi connection to my nvidia card from my lcd pj.

Ive definitely got 16/235 levels sorted, and now color temps was next on the list, but how do i go about calibrating it.Also i see that changing rgb gain/offset settings seem to change my white levels higher or lower accordingly???

By the way how do i adjust hue/saturation on a pj using dvi?i use theatertek 2.1.1, and have an avia disk.

Last question, Gamma, can this be calibrated on a htpc or is this something im going to have this sort out professionally???

thanks to all in advice
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post #210 of 486 Old 07-29-2005, 05:53 AM
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You really need test equipment (like OpticOne, etc) to do any meaningful calibration of RGB gain, offset and gamma.

See what an anamorphoscopic lens can do,
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