Pana NV-HS960 TBC pumps brightness?

[prodarek]

Hi, I noticed when I turn on TBC, brightness go up this is normal? anyone know how good is TBC in this model? or maybe better to buy ES15?

[dellsam34]

Possibly coupled with other processing, try to read the user manual and find out if you can turn off some processing without turning off the TBC.

[prodarek]

Ofc we talking about internal TBC in panasonic 960, sorry if I wasn't thorough.

[Alwyn]

The ES-15 also boosts the whites (I haven't made any attempt to lower the brightness/contrast from default for these captures).

[Sharc]

The ES-15 also boosts the whites (I haven't made any attempt to lower the brightness/contrast from default for these captures).

Yes, see for example frames 180 to 250 where the cloud structure in the sky is almost completely gone for the ES15 capture. Level adjustments are often required for passthrough configurations. It can be a combination of proc-amp settings during capturing and post processing.

Sidenote: The interlaced video is encoded as progressive. The color primaries are BT.709 instead of 601. I guess it came along with the SBS arrangement....

[Sharc]

Possibly coupled with other processing, try to read the user manual and find out if you can turn off some processing without turning off the TBC.

That's what the manual of the NV-HS960B says about its DNR and TBC.

[Attachment 63281 - Click to enlarge]

[prodarek]

This brightness this is not big problem I have pioneer dvr 560h and I can way fix this using black level switch. but I think I will buy es15 to test vs pana 960 tbc.

[Sharc]

You could also try DVR 560H in passthrough mode. It has composite video in and S-video out which should provide TBC functionality. I would just try it before buying an ES15.

[prodarek]

560H has 2x s-video input and 2x s-video, yes I need more tests but I dont have capture card I use only pioneer to rec.
Image when I watch is definitively better than I recording.

[dellsam34]

Possibly coupled with other processing, try to read the user manual and find out if you can turn off some processing without turning off the TBC.

That's what the manual of the NV-HS960B says about its DNR and TBC.

For capturing, 3D DNR should be off to disable all processing, I don't know if the OP is talking about this function that boosts the level or the TBC, If it's the TBC while 3D DNR is turned off then there is something wrong with the VCR, Line TBC should be transparent as it only fixes horizontal timing signal.

[prodarek]

I'm talking about TBC button/function, TBC and 3D-DNR this is separated functions in pana 960.
From my observation in my pana 960:
TBC function after turn on boost brightness.
3D DNR function after turn on reduce noise and image is more stable, I don't noticed any color changes.

..and question is "who have pana 960 and can confirm this observations"

[Sharc]

I'm talking about TBC button/function, TBC and 3D-DNR this is separated functions in pana 960.
From my observation in my pana 960:
TBC function after turn on boost brightness.
3D DNR function after turn on reduce noise and image is more stable, I don't noticed any color changes.

..and question is "who have pana 960 and can confirm this observations"

Nobody, apparently.....
So either nobody has tested it, or the TBC of the 960 triggers other functions under the hood, or your 360 is flawed....
How much is the brightness boosted? Upload 2 samples (TBC off vs TBC on) and you may get more comments.

[prodarek]

No diff not is big

left tbc off
right tbc on

[Sharc]

There seems to be a shift of about 4 in luma, yes, for picture 2 and 3. No idea as to why this happens.
(The 1st picture is not the same frame, so the comparison is not applicable there).

[dellsam34]

I don't see much of brightness difference at all, I don't know what the OP is talking about. Maybe a video sample will show the problem better.

[Sharc]

You may not see the small shift immediately. You can however demonstrate it by separating and comparing the OFF and ON pictures individually, using

histogram("classic") #or histogram("levels")

or

coloryuv(analyze=true) #compare the "Average" values of the Luma.

You'll find a difference for the luma of about 3....4 steps (on a 0....255 8 bit scale) between the OFF and ON pictures.

[prodarek]

Diff depends on monitor config and in night on TV is much more noticeable.
-1 black level set in pioneer dvr 560h and its ok now

[dellsam34]

If the TBC on the right screen shots your thread title should be reversed, The left ones are slightly brighter, Though it is not considered an issue in the analog world.

[jagabo]

It doesn't matter if the TBC causes a slight levels shift. Just adjust your capture devices proc amp to compensate. That's what it's there for. Of fix it in post. It's only a problem if it causes the brights or darks to get crushed.

I believe the DVD passthrough adjusts the levels based on the horizontal sync pulse amplitude and the blanking level. And the saturation based on the chroma burst amplitude.


[Attachment 63375 - Click to enlarge]

As you can see the horizontal blanking level defines IRE 0. The horizontal sync pulse is supposed to be at -40 IRE. If, for example, a perfect signal has passed through a very long cable the amplitude of the sync pulse might be reduced to -30 IRE. So it is amplified by 1.33 to restore it to -40. The video levels will have been attenuated by the same amount so they are also amplified. If you had adjusted your capture device's proc amp for the original weak signal you will get blown out brights with the fixed levels of the DVD passthrough.

[prodarek]

If the TBC on the right screen shots your thread title should be reversed, The left ones are slightly brighter, Though it is not considered an issue in the analog world.

right is after tweak -1 black level.