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View Full Version : Light sensor doesn't work in PC mode (47PFL4606)



kmzkmz
03-13-2012, 12:11 PM
Hello.
When I have "PC mode - On" Light sensor stops working. It's definitely a software bug as I can see changes of light intensity in "Active Control - Light sensor" menu but backlight isn't adjusted.

Philips - Thomas
03-13-2012, 02:03 PM
Hi,

Its normal that all picture optimizing features (including the light sensor) are disabled in case you add a device as "Computer" / "Game console" or you switch on a anonymous source (add a device and switch via SOURCE - button to this device) and then enable the “PC Mode”.

Note that this is necessary to avoid an inputlag (= delay between your control interaction and display reaction). Additionally, if you use the TV as a PC monitor it should be ensured that you have a neutral display with fix brightness and contrast adjustments so that you can work with it for some ours without straining eyes.

Thats the background for this behavior. It means no bug.

Regards,
Thomas

kmzkmz
03-13-2012, 02:19 PM
Note that this is necessary to avoid an inputleg (= delay between your control interaction and display reaction). Additionally, if you use the TV as a PC monitor it should be ensured that you have a neutral display with fix brightness and contrast adjustments so that you can work with it for some ours without straining eyes.

1. But how adjusting of backlight can cause input lag? It's not some heavy image processing(sharpening/color correction/etc).

2. "...without straining eyes" But current behavior DOES lead to straining of eyes as it's impossible to control backlight manually and it's VERY high even with 50 Contrast. Because of that it's almost painful to look at TV in the evening even with lights on in the room.

Philips - Thomas
03-13-2012, 03:15 PM
Hi,

Of course, every picture optimizing feature has an minor or major influence on the display latency.
But Back to your actual issue:

Please try to improve the picture quality with the following steps:

HOME > Setup > TV Settings > Picture > Pixel Plus HD:

Dynamic contrast > off
Dynamic backlight > off

Now adjust the brightness / contrast manually:

HOME > Setup > TV Settings > Picture:

* Contrast
* Brightness

Please provide the result after you tested it.

Thanks in advance,
Thomas

kmzkmz
03-13-2012, 04:22 PM
Of course, every picture optimizing feature has an minor or major influence on the display latency.

Well, what I was trying to tell it doesn't look like PICTURE optimizing feature it's just simple adjusting of the backlight according to the level of light in the room(hardware sensor) and it can be done independently of major image "enhancement". But OK, if you say it leads to input lag I have no reasons to not believe you. :)


HOME > Setup > TV Settings > Picture > Pixel Plus HD:

Dynamic contrast > off
Dynamic backlight > off

Now adjust the brightness / contrast manually:

HOME > Setup > TV Settings > Picture:

* Contrast
* Brightness

Please provide the result after you tested it.

I've already tested all this that's why I created this thread. Here are the results:

Dynamic contrast/backlight cannot be controlled in PC mode. And switching PC mode off leads to another issue(seems widely known http://www.supportforum.philips.com/en/showthread.php?1874-42PFL4606H-58-Major-issues-with-current-FW-%282.07%29) with image oversharpening even when Sharpness is off. And it's obvious that you cannot play games from PC and watch FullHD videos with that.

Also decreasing of Brightness without major loss of image quality is limited in very narrow range of ~ 50-45. So only way to actually decrease backlight is Contrast, but below 50 it seems to affect image quality too.
And as you're not willing to fix sharpening bug and add manual backlight control (my previous LG TV had it btw) I thought that "fixing" of Light sensor would be a simple solution for this problem. I even can accept the fact that with "Light sensor - On" I'll have a bit larger lag, but at least I'll be able to normally use TV in the evening.

kmzkmz
03-15-2012, 11:34 AM
Philips - Thomas
So can I expect some improvements in next firmware update e.g. working Light sensor or ability to decrease backlight by contrast below 50 without compromising quality of picture (I can provide photos what I mean by "compromising quality") or ...?
Or you in Philips have some regulation that FORBIDS customers to play games/watch FullHD movies from PC in the evening?

rival82
04-11-2012, 08:57 PM
I have the 40PFL5706/f7 model and i also have this bug.

The screen backlight turns up very high when using the vga computer input. It stays high if i turn on net tv. I have to turn off net tv and select a hdmi or tv antenna input for the backlight to dim back to a normal level, only then can i use net tv without the backlight being too high.

Active control seems to disable itself on vga, also when watching a video or viewing pictures from the televisions usb port the active control deactivates and the screen backlight shoots back up again.

I know for a fact that on vga or usb input the latency should not be an issue, slight image lag could NEVER be caused by providing less power to the backlight inverter. - My source for this info is years of experience working with computers and perihpials including repairing lcd screens of all types.

rival82
04-11-2012, 11:46 PM
Its normal that all picture optimizing features (including the light sensor) are disabled in case you add a device as "Computer" / "Game console" or you switch on a anonymous source (add a device and switch via SOURCE - button to this device) and then enable the “PC Mode”.

Also, here the "active control" works well when using a game console through component and hdmi...........