"Calibrating" 50" consumer plasma

megabit wrote on 6/29/2010, 12:24 AM

I have one of these rather top Panasonic Viera, 50" plasma models, which I use for watching my own video, Hollywood BDs, and HD broadcast - but also in Vegas editing, as the Secondary Monitor (it's hung above my 24" desktop monitor, also full HD). The picture on the plasma is just great - so much so that with a really good material, watching it from some 1-1.5m distance is not too close at all.

In my quest to get rid of some noise my EX1/nanoFlash combo produces, I thought I'd check how far from being calibrated my plasma is (never tried that before, as being aware this is just a consumer grade device, I thought it wouldn't be possible - I just made sure all the "enhancements" were off).

So, I picked the SMPTE bars (NTSC) in Vegas, and displayed them on my plasma. The subtle difference between those dark gray and black short bars of the "pluge" areas in the lower right portion are completely gone - everything is deep black!

I couldn't stretch the gray to see it even with contrast all the way down, and brightness all the way up (which of course would make video look extremely milky, anyway).

So, I turned off Color Management in my Secondary Display properties - and voila! - the gray bars are visible! BUT, the actual video from Vegas timeline look extremely washed out...

My question arising from this experiment is following: we've been taught (by Glenn at al) that with mpg2 on the timeline, and with 8bit pixel format, the way for getting proper levels on secondary monitor is to use color Management into sRGB color space. And yes - when engaged, the video looks stunning (apart from some noise), but - at least watching the SMPTE bars - the colors are far from calibrated....

Any explanation?

Comments

megabit wrote on 6/29/2010, 1:22 AM

It just occurred to me that the SMPTE bars (generated media in Vegas) might NOT require conversion to sRGB on the secondary monitor... Anyone know it for sure?

Also, I should have added that on the Primary desktop monitor (a 24" Fujitsu, 1920x1200), even though I'm using Color Management and the sRGB color space profile, the SMPTE bars look OK while the video has proper levels... Now, there is a tool in Vista for setting color management of a PnP (generic) monitor - perhaps I should use that for my Plasma (on the Secondary DVI output)? But I guess this setting is only working for the OS itself, not necessarily Vegas...

Again - anyone has a deeper knowledge?

Piotr

ushere wrote on 6/29/2010, 2:47 AM

also very interested in hearing what's going on, or to be done with 'consumer' lcd/plasma screens as second monitors.

which leads me on to asking is it worth getting a cheap spyder from b&h to calibrate it (yes, i know, but as close to)

leslie

farss wrote on 6/29/2010, 3:24 AM

From here

"When a monitor is properly adjusted, the rightmost pluge bar should be just barely visible, while the left two should appear completely black."

Bob.

craftech wrote on 6/29/2010, 3:39 AM

Piotr,

I would suggest you download and burn this Free HD Calibration DVD from AVS Forum. It has far more pluge and other grayscale patterns in addition to everything found on commercial calibration discs. There are 75 pages of discussion as well. You should have enough range in the Custom setting for the Picture menu to get it within the Calibration DVD's provided patterns.

There are ways to change the range of values in the menu for your Panasonic Viera by going into the Service Menu. I would suggest that you do not do that. It is very easy to get them screwed up and not know how to get them back. The original values vary from set to set ( not model to model, but EACH set is individually factory calibrated). If you feel compelled to mess with the Service Menu I can walk you through it.

John

megabit wrote on 6/29/2010, 3:39 AM

Yes Bob - I'm fighting to make the pluge bars barely visible; with sRGB mapping all the pluge area is just deep black (on the plasma - not on the desktop LCD).

When I use Levels FX on the SMPTE bars in Vegas to "Convert from sRGB to cRGB", the gray pluge bar just start to appear on the plasma, as well. But I cannot do the same to my mxf (mpg2) video, or it will look milky.

megabit wrote on 6/29/2010, 3:42 AM

John,

Thanks for all the info. Before I even consider going to the service menu, I must grasp the idea why - with video levels appearing right by eye - the pluge bar is not visible at all...

craftech wrote on 6/29/2010, 4:05 AM

Thanks for all the info. Before I even consider going to the service menu, I must grasp the idea why - with video levels appearing right by eye - the pluge bar is not visible at all...
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As I said Piotr I do not recommend going into the Service Menu. I do, however recommend that you calibrate using the HD 709 Patterns Disc that is free for download in several different HD types.

John

megabit wrote on 6/29/2010, 4:09 AM

I just have downloaded it, John - thaks again.

After I burn the disk, and try the calibration, I'll report back.

Piotr

craftech wrote on 6/29/2010, 4:14 AM

Also, I am not sure if your input source has any output settings that could affect the results. You should check that.

For example, if one uses the disc through a PS3, there is a Superwhite setting that should be turned off or the calibration will be way off. Maybe the mp4 version played through your camera (if that's possible) would work better. Experiment.

John

farss wrote on 6/29/2010, 5:28 AM

The problem I have is knowing exactly what you're calibrating compared to what.
1) Vegas's test patterns haven't been updated since before the days of HD.
2) There are mulitple places throughout the signal chain that affect the signal.
a) My nVidia Control Panel has a set of adjustments.
b) Windows has a set of adjustments.
c) Vegas has a set of adjustments including using icc profiles.
d) The monitor has adjustments.

There's no way to know WHAT is going into the monitor when you're "calibrating" it which makes the whole exercise kind of pointless. That probably explains why the pros with deep pockets use SDI monitors, you can measure what is going into the monitor.
As most of us are not so lucky as to afford such expensive kit my best suggestion is this.
Reset your EX1 and record the IRIG bars. Drop those onto the Vegas T/L and tweak all or any of the above from a) to d) until you get the right result.
To be honest I don't know even if you had a Spyder or some such just how much value it'd really be. Probably it'd be fine if you're working with printers and scanners, I just don't know for sure how it all works with video and the signal chains inside the PC abd video card.

Bob.

craftech wrote on 6/29/2010, 9:13 AM

There's no way to know WHAT is going into the monitor when you're "calibrating" it which makes the whole exercise kind of pointless
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It's not pointless really because if he sets up the Plasma with a good calibration disc so it is accurate, he can then leave the television alone and look elsewhere if there is still an issue. As far as using the Plasma as a Secondary monitor, I have never tried that. I use a CRT Pro Monitor instead.

John

megabit wrote on 6/29/2010, 9:28 AM

Bob and John,

What I'm planning to do is burn the test BD, and try to calibrate )or at least check) my plasma using a stand-alone BD player - thus bypassing Vegas, OS, and graphics card settings. Only then, I'll try and tune my Vegas installation (hw/sw-wise) to resemble what I arrived at in step 1.

The EX1-recorded bar pattern suffers from exactly the same now as the Vegas internal SMPTE one - i.e. no gray visible, just deep black.

On the other hand, if I increase the brightness on the plasma to make the gray visible, the normal video (or TV broadcast, for that matter) is definitely wrong.

This raise the questions again:

- Should the bar pattern be 0-100 IRE, or converted to sRGB in Vegas?

Piotr

PS. BTW, John, my plasma works great as the Vegas Secondary Monitor - the EX1's mxf looking gorgeous color and level-wise. The only reason I want to fine-tune it is it's a bit prone to exaggerate noise (yeah, yeah I know - this has nothing to do with colors and levels, but perhaps I'm just using it with too high contrast? This could exaggerate mid-lit area noise...

Piotr

farss wrote on 6/30/2010, 1:50 AM

" Should the bar pattern be 0-100 IRE, or converted to sRGB in Vegas?"

The pluge patchs are (roughly) -5, 0 , +5 IRE from left to right. Technically the blackest one is illegal and should look as black as as the 0 IRE one with the +5 IRE one just visible. My understanding is those three allow you to get your black set correctly, too far one way you see none, too far the other way you can see all of them.

Maybe I can help some more as I just realised a couple of our monitors also have waveform displays and they will accept HDMI inputs. Probably cannot bring one home until the weekend so bear with me.

Bob.

FrigidNDEditing wrote on 6/30/2010, 1:57 AM

I've been looking at samsung UN40C5000 LED Backlit LCD as a possible HD TV monitor.

It is able to display Red, Green, and Blue individually providing a "blue gun" type of effect for calibrating, and can be had for under $1K, plus it's very thin, and has a very nice picture.

Dave

craftech wrote on 6/30/2010, 4:34 AM

Use the AVS HD 709 Disc with this excellent tutorial on Greyscale and Color Calibration. If you don't want to buy some of the stuff he recommends it is still very useful by itself. The free ColorHCFR is very useful.

John

Jeff9329 wrote on 6/30/2010, 10:14 AM

Is your Panasonic THX certified, ie a G10? I have a G10 and can attest it can be ISF calibrated to near conformance. The latest firmware 1.28 also gets the THX settings pretty close.

You are going to need a Sencore video generator and a comparator to calibrate a G10 with any accuracy. You are also going to need a day & night calibration if there are any windows in the room. ISF cals have dropped dramatically in cost the last few years if you are in a major metro area. Maybe as low as $300.

Bottom line, the Panasonic G10 will calibrate and is a top rated color accurate HDTV. The newest high end LGs are going to the next level and supporting ISFccc.

Also, the Panasonics are not input specific calibrations like Pioneers, Hitachis and other high end sets were. You will need to set a custom calibration for the input and device and save it and go back to that cal when you use that input/device.

Are you using a Blackmagic card for output?