Mailing List Archive: MythTV: Users

How to properly adjust brightness and contrast

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boberz at thewatch

Aug 10, 2008, 3:06 PM

Post #1 of 15 (1803 views)
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How to properly adjust brightness and contrast

Is there a howto or a document on a wiki somewhere regarding the best
way to properly adjust the brightness, contrast, color, and hue settings
on a tuner to get things looking their best?

I'm using Happague PVR-150 tuners, and at the default settings the
picture is very dark. I've figured how how to adjust the settings, I
just really don't know how to properly adjust them all in concert to get
the best picture possible.

Any advice is appreciated. Thanks!

- Nick
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jruss at mit

Aug 10, 2008, 5:19 PM

Post #2 of 15 (1739 views)
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Re: How to properly adjust brightness and contrast [In reply to]

I would also love to see some guidance on a proper way to adjust these
settings. I have the same issue with my PVR-150. I get things looking
acceptable by taking the contrast down a few notches and bumping up the
brightness until it looks OK.

I have seen little widgets that guide you through the adjustments on a
computer monitor, or even calibration images with set of instructions for
adjusting the brightness, contrast, etc. Is there anything like this that
could be used in mythtv? I know that you have to be recording to make the
adjustments so a widget or calibration image is probably too much to ask
for. But there must be some order/logic to which settings to change and how.

boberz at thewatch

Aug 10, 2008, 6:07 PM

Post #3 of 15 (1747 views)
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Re: How to properly adjust brightness and contrast [In reply to]

Johnny Russ wrote:
> I would also love to see some guidance on a proper way to adjust these
> settings. I have the same issue with my PVR-150. I get things looking
> acceptable by taking the contrast down a few notches and bumping up
> the brightness until it looks OK.
>
> I have seen little widgets that guide you through the adjustments on a
> computer monitor, or even calibration images with set of instructions
> for adjusting the brightness, contrast, etc. Is there anything like
> this that could be used in mythtv? I know that you have to be
> recording to make the adjustments so a widget or calibration image is
> probably too much to ask for. But there must be some order/logic to
> which settings to change and how.
That's what I'm hoping to find. Basically, how does one go about
adjusting things? I've done the ones for monitors but that only has
brightness and contrast - it does not include color and hue.

A simple write up of what order to adjust, sane starting points, and
what to look for is all I'm trying to find.

- Nick
> ------------------------------------------------------------------------
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users [at] mythtv
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>

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bradallenfuller at gmail

Aug 10, 2008, 6:22 PM

Post #4 of 15 (1748 views)
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Re: How to properly adjust brightness and contrast [In reply to]

On Sun, Aug 10, 2008 at 6:07 PM, Nick Bright <boberz [at] thewatch> wrote:
> Johnny Russ wrote:
>> I would also love to see some guidance on a proper way to adjust these
>> settings. I have the same issue with my PVR-150. I get things looking
>> acceptable by taking the contrast down a few notches and bumping up
>> the brightness until it looks OK.
>>
>> I have seen little widgets that guide you through the adjustments on a
>> computer monitor, or even calibration images with set of instructions
>> for adjusting the brightness, contrast, etc. Is there anything like
>> this that could be used in mythtv? I know that you have to be
>> recording to make the adjustments so a widget or calibration image is
>> probably too much to ask for. But there must be some order/logic to
>> which settings to change and how.
> That's what I'm hoping to find. Basically, how does one go about
> adjusting things? I've done the ones for monitors but that only has
> brightness and contrast - it does not include color and hue.
>
> A simple write up of what order to adjust, sane starting points, and
> what to look for is all I'm trying to find.
>

Some guidance:

http://autopattern.maettig.com/?lang=en
http://www.linux.com/articles/113936
http://www.epaperpress.com/monitorcal/
http://www.normankoren.com/color_management.html

--
Brad Fuller
www.bradfuller.com
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nick.rout at gmail

Aug 10, 2008, 7:36 PM

Post #5 of 15 (1727 views)
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Re: How to properly adjust brightness and contrast [In reply to]

On Mon, Aug 11, 2008 at 1:07 PM, Nick Bright <boberz [at] thewatch> wrote:
> Johnny Russ wrote:
>> I would also love to see some guidance on a proper way to adjust these
>> settings. I have the same issue with my PVR-150. I get things looking
>> acceptable by taking the contrast down a few notches and bumping up
>> the brightness until it looks OK.
>>
>> I have seen little widgets that guide you through the adjustments on a
>> computer monitor, or even calibration images with set of instructions
>> for adjusting the brightness, contrast, etc. Is there anything like
>> this that could be used in mythtv? I know that you have to be
>> recording to make the adjustments so a widget or calibration image is
>> probably too much to ask for. But there must be some order/logic to
>> which settings to change and how.
> That's what I'm hoping to find. Basically, how does one go about
> adjusting things? I've done the ones for monitors but that only has
> brightness and contrast - it does not include color and hue.
>
> A simple write up of what order to adjust, sane starting points, and
> what to look for is all I'm trying to find.

Remember the "test pattern" that used to broadcast when TV wasn't?
Seems to have gone away now that we have 24 hour entertainment on the
box.
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digitalaudiorock at gmail

Aug 10, 2008, 7:50 PM

Post #6 of 15 (1744 views)
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Re: How to properly adjust brightness and contrast [In reply to]

On Sun, Aug 10, 2008 at 6:06 PM, Nick Bright <boberz [at] thewatch> wrote:
> Is there a howto or a document on a wiki somewhere regarding the best
> way to properly adjust the brightness, contrast, color, and hue settings
> on a tuner to get things looking their best?
>
> I'm using Happague PVR-150 tuners, and at the default settings the
> picture is very dark. I've figured how how to adjust the settings, I
> just really don't know how to properly adjust them all in concert to get
> the best picture possible.
>
> Any advice is appreciated. Thanks!
>
> - Nick
> _______________________________________________
> mythtv-users mailing list
> mythtv-users [at] mythtv
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>

I guess that's one nice thing about all digital TV. I'm using
HD-5500s for OTA DTV. I just calibrated by TV using an Avia Guide to
Home Theater DVD and all my shows look perfect. I guess when it comes
to analog tuning you've got nothing to use as a reference.

Tom
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allen.edwards at oldpaloalto

Aug 10, 2008, 9:10 PM

Post #7 of 15 (1727 views)
Permalink

Re: How to properly adjust brightness and contrast [In reply to]

Nick Bright wrote:
> Johnny Russ wrote:
>> I would also love to see some guidance on a proper way to adjust these
>> settings. I have the same issue with my PVR-150. I get things looking
>> acceptable by taking the contrast down a few notches and bumping up
>> the brightness until it looks OK.
>>
>> I have seen little widgets that guide you through the adjustments on a
>> computer monitor, or even calibration images with set of instructions
>> for adjusting the brightness, contrast, etc. Is there anything like
>> this that could be used in mythtv? I know that you have to be
>> recording to make the adjustments so a widget or calibration image is
>> probably too much to ask for. But there must be some order/logic to
>> which settings to change and how.
> That's what I'm hoping to find. Basically, how does one go about
> adjusting things? I've done the ones for monitors but that only has
> brightness and contrast - it does not include color and hue.
>
> A simple write up of what order to adjust, sane starting points, and
> what to look for is all I'm trying to find.
>
> - Nick
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users [at] mythtv
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users [at] mythtv
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
You can buy a DVD that includes filters that you look through at the
test patterns that allow you to balance the different colors. You need
one of the digital ones for a digital screen but if you have a TV with
just tint and color controls, the first one of these will be fine. I
have 3 of the 4.
http://reviews.cnet.com/4520-6463_7-5085739-3.html?tag=txt

Allen

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anaerin at gmail

Aug 10, 2008, 9:24 PM

Post #8 of 15 (1715 views)
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Re: How to properly adjust brightness and contrast [In reply to]

Tom Dexter wrote:
> On Sun, Aug 10, 2008 at 6:06 PM, Nick Bright<boberz [at] thewatch> wrote:
>> Is there a howto or a document on a wiki somewhere regarding the best
>> way to properly adjust the brightness, contrast, color, and hue settings
>> on a tuner to get things looking their best?
>>
>> I'm using Happague PVR-150 tuners, and at the default settings the
>> picture is very dark. I've figured how how to adjust the settings, I
>> just really don't know how to properly adjust them all in concert to get
>> the best picture possible.
>>
>> Any advice is appreciated. Thanks!
>>
>> - Nick
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users [at] mythtv
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
>
> I guess that's one nice thing about all digital TV. I'm using
> HD-5500s for OTA DTV. I just calibrated by TV using an Avia Guide to
> Home Theater DVD and all my shows look perfect. I guess when it comes
> to analog tuning you've got nothing to use as a reference.

ISTR, if you have a "THX Certified" DVD (One on this list:
http://www.thx.com/home/dvd/search.html), you can use the included "THX
Optimizer" to tweak your settings. It's not perfect, and certainly not
theatre-grade, but it will ensure your picture is mostly accurate.
--
Robert Johnston
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jruss at mit

Aug 11, 2008, 6:49 AM

Post #9 of 15 (1695 views)
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Re: How to properly adjust brightness and contrast [In reply to]

>
> ISTR, if you have a "THX Certified" DVD (One on this list:
> http://www.thx.com/home/dvd/search.html), you can use the included "THX
> Optimizer" to tweak your settings. It's not perfect, and certainly not
> theatre-grade, but it will ensure your picture is mostly accurate.
>

The OP and myself are having issues with the settings in the PVR-150 tuner,
not with our TV. Everything looks fine on my TV from sources other than the
PVR-150. It is the brightness, contrast, color settings of the tuner itself
that are off. The only way to adjust them is to do so while that tuner is
recording. Is there someway to route a DVD to the coax input on the PVR-150?
If I route the DVD player through the svideo input on my PVR-150, and adjust
that will those settings apply to the coax input also? It seems like they
wouldn't because they would be setup as different inputs in MythTV.

drescherjm at gmail

Aug 11, 2008, 7:10 AM

Post #10 of 15 (1702 views)
Permalink

Re: How to properly adjust brightness and contrast [In reply to]

> The OP and myself are having issues with the settings in the PVR-150 tuner,
> not with our TV. Everything looks fine on my TV from sources other than the
> PVR-150. It is the brightness, contrast, color settings of the tuner itself
> that are off.
I have had this darkness on only a single channel on one of my
pvr150s. I solved it through experimentation and by changing the
params in mythweb. With that said I am not 100% happy with the color
settings.

> The only way to adjust them is to do so while that tuner is
> recording. Is there someway to route a DVD to the coax input on the PVR-150?
>
I would use coax. Doesn't your standalone dvd player output on channel 3 or 4?

> If I route the DVD player through the svideo input on my PVR-150, and adjust
> that will those settings apply to the coax input also?
> it seems like they
> wouldn't because they would be setup as different inputs in MythTV.
>
I do not think so.

John
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jra at baylink

Aug 11, 2008, 7:35 AM

Post #11 of 15 (1690 views)
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Re: How to properly adjust brightness and contrast [In reply to]

On Sun, Aug 10, 2008 at 05:06:26PM -0500, Nick Bright wrote:
> Is there a howto or a document on a wiki somewhere regarding the best
> way to properly adjust the brightness, contrast, color, and hue settings
> on a tuner to get things looking their best?

Probably the most important thing to know is that the IVTV drivers and
Hauppauge cards support the setting of brightness and the like on both
*record and playback*. Zero the playback settings and set the record
ones *first*.

Cheers,
-- jra
--
Jay R. Ashworth Baylink jra [at] baylink
Designer The Things I Think RFC 2100
Ashworth & Associates http://baylink.pitas.com '87 e24
St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274

Those who cast the vote decide nothing.
Those who count the vote decide everything.
-- (Josef Stalin)
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richardwoelk at yahoo

Aug 11, 2008, 9:28 AM

Post #12 of 15 (1687 views)
Permalink

Re: How to properly adjust brightness and contrast [In reply to]

Nick Bright wrote:
> Is there a howto or a document on a wiki somewhere regarding the best
> way to properly adjust the brightness, contrast, color, and hue settings
> on a tuner to get things looking their best?
>
> I'm using Happague PVR-150 tuners, and at the default settings the
> picture is very dark. I've figured how how to adjust the settings, I
> just really don't know how to properly adjust them all in concert to get
> the best picture possible.
>
> Any advice is appreciated. Thanks!
>
> - Nick
>

I used the Avia DVD repeating a color bars pattern in a set top player
connected to the s-video input of my pvr-150.
Mythtv keeps the global settings per capture card, not input. It also
keeps individual channel settings.

While watching live TV, Press CTRL-G to get recorder settings. press G
to get channel settings.
The channel settings won't start at 50, they will show what the current
card settings are.

When you increase the contrast too high, it will crush the whites, if
its too low, the black looks washed out.
The difficulty is that the capture card doesn't clamp the black level.
so when you adjust the contrast, you'll have to go back and adjust the
brightness again.
for color and hue, you need the blue filter to look through.

for starters, I found these settings on my PVR-150 OEM from s-video input.
The tuner input is quite a bit worse. (or that could be what my off air
is like)

Brightness - 48
Contrast - 42
Color - 44
Hue - 50

I also found a filter for virtualdub on windows called color tools that
let me view vectorscope and waveform patterns. I could import the mpeg
and see the effects a few seconds later.

I always wished I could use this as a playback filter in mythtv, that
way it would be a lot easier to set capture properly.

- Richard
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boberz at thewatch

Aug 11, 2008, 11:06 AM

Post #13 of 15 (1687 views)
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Re: How to properly adjust brightness and contrast [In reply to]

Johnny Russ wrote:
> ISTR, if you have a "THX Certified" DVD (One on this list:
> http://www.thx.com/home/dvd/search.html), you can use the included "THX
> Optimizer" to tweak your settings. It's not perfect, and certainly not
> theatre-grade, but it will ensure your picture is mostly accurate.
>
>
> The OP and myself are having issues with the settings in the PVR-150
> tuner, not with our TV. Everything looks fine on my TV from sources
> other than the PVR-150. It is the brightness, contrast, color settings
> of the tuner itself that are off. The only way to adjust them is to do
> so while that tuner is recording. Is there someway to route a DVD to the
> coax input on the PVR-150? If I route the DVD player through the svideo
> input on my PVR-150, and adjust that will those settings apply to the
> coax input also? It seems like they wouldn't because they would be setup
> as different inputs in MythTV.

Maybe use an old VCR? those all have RF output :)

>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users [at] mythtv
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

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boberz at thewatch

Aug 11, 2008, 11:07 AM

Post #14 of 15 (1671 views)
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Re: How to properly adjust brightness and contrast [In reply to]

Jay R. Ashworth wrote:
> On Sun, Aug 10, 2008 at 05:06:26PM -0500, Nick Bright wrote:
>> Is there a howto or a document on a wiki somewhere regarding the best
>> way to properly adjust the brightness, contrast, color, and hue settings
>> on a tuner to get things looking their best?
>
> Probably the most important thing to know is that the IVTV drivers and
> Hauppauge cards support the setting of brightness and the like on both
> *record and playback*. Zero the playback settings and set the record
> ones *first*.

Thanks for the tip - I didn't know that!

>
> Cheers,
> -- jra

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n0nb at n0nb

Aug 11, 2008, 2:31 PM

Post #15 of 15 (1659 views)
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Re: How to properly adjust brightness and contrast [In reply to]

* Johnny Russ <jruss [at] mit> [2008 Aug 11 08:49 -0500]:
> >
> > ISTR, if you have a "THX Certified" DVD (One on this list:
> > http://www.thx.com/home/dvd/search.html), you can use the included "THX
> > Optimizer" to tweak your settings. It's not perfect, and certainly not
> > theatre-grade, but it will ensure your picture is mostly accurate.
> >
>
> The OP and myself are having issues with the settings in the PVR-150 tuner,
> not with our TV. Everything looks fine on my TV from sources other than the
> PVR-150. It is the brightness, contrast, color settings of the tuner itself
> that are off. The only way to adjust them is to do so while that tuner is
> recording. Is there someway to route a DVD to the coax input on the PVR-150?
> If I route the DVD player through the svideo input on my PVR-150, and adjust
> that will those settings apply to the coax input also? It seems like they
> wouldn't because they would be setup as different inputs in MythTV.

I'm using the PVR-150 as well fed from my satellite STB S-Video out to
its S-Video in and the color balance is good. However, it was the
TV-out signal from the S-Video output that was dark and off color. I
figured that out by using Twinview and watching the video on a monitor
from the VGA port. I've since added an Averkey iMicro which gets me a
good picture, but seems to dither the color and doesn't keep up with
full motion video well.

So, can you verify the recording is wrong when viewing it on a known
good monitor via the VGA port? BTW, I have all of the recording color
balance settings at the Mythbuntu defaults of 50%.

- Nate >>

--

"The optimist proclaims that we live in the best of all
possible worlds. The pessimist fears this is true."

Ham radio, Linux, bikes, and more: http://n0nb.us/index.html
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