The auto-contrast is driving me nuts... - Asus Eee Pad Transformer Prime

I`m very happy with my prime, and apart from the gps it seems to be without faults. But the auto contrast is really annoying. I get why it`s on in powersaving mode, but it is still there, even in performance mode. Is there any way to turn it off? I hope this can be brought to Asus`s attention.
Sent from my Transformer Prime TF201 using xda premium

This might be what you seeing at work. Its a new innovative technology from nvidia implented in tegra3 for further battery savings. They have another feature they added also but can't find the description on it.
" NVIDIA PRISM Display Technology - PRISM (or Pixel Rendering Intensity and Saturation Management) reduces a mobile device’s backlight power while simultaneously enhancing the pixel color to deliver the same visual quality with substantially extended battery life."

I have never had an issue like you describe... anyone else? Is it happening more in bright situations or what?

I don't have anything like this. Do you have auto brightness turned on? Could it be tied to that?
Sent from my Transformer Prime TF201 using Tapatalk

Get out of powersave mode.

I have noticed this too. On several occasions I have noticed the screen getting brighter or dimmer for no reason. I have checked and the Auto Brightness IS off. It doesn't happen all the time but I have noticed it.

I have auto brightness turned off, and I sometimes get this problem while watching certain YouTube videos. I can't think of any specific ones off hand. It's pretty annoying. I always run in balanced mode.

Same problem here.
A really simple way to see that, is set the contrast to the minimal (like when in bed ) and watch any video the luminosity will flicker a lot.
It seems that starting from 25% luminosity this effect is way less visible (even if still here).

Hmm... I've always had auto-brightness off and the display has never changed on its own.
But I usually have the brightness very low, and this may be my inability to notice these kinds of things.

Just did some testing, it's less visible when the brightness is turned up a bit, but still there. But I tried a regular movie, and I didn't notice it, but it was very obvious when watching anime. It happens in every power mode. I guess I can live with it if it's only visible when watching anime though...
Sent from my Transformer Prime TF201 using xda premium

I think you are talking about Tegra 3 DIDIM tecnology
and it can't be disabled on TFP

yeh, I guess that's it. I wish they would implement a way to have it disabled in performance mode at least.
Sent from my Transformer Prime TF201 using xda premium

I wonder if it's hardware related or software/driver related. Hopefully in future rom developers find a way how to disable it because it's really really annoying.

The best way to see it is to turn your brightness all the way down, go into a dark room, and play a YouTube video. You'll definitely see the contrast/brightness changing.
Sent from my ROOTED Transformer Prime

The above describes this issue perfectly. All the resets in the world will not fix it, I'm afraid. This is a "feature" of the Tegra 3 chip to increase battery life. I have been experimenting with this extensively. You will notice this much more when brightness is set low (in my case, below 20% or so). It is especially evident in large white or light grey areas of the screen. You will notice what looks like automatic readjustments of the brightness of these areas. It will appear as though the screen is the automatically increasing and decreasing brightness - and the effect is by no means subtle. Try watching a video where there is a lot of white sky. Have a look at this video:
Search for Youtube Video "St Patrick Swipe" if you wish. Set your brightness at about 10%, with auto brightness off. Ensure you are in Balanced power mode or Performance power mode (the effect is very evident in Powersave mode if you want to try that, but I guess that is to be expected). Switch the video to full screen and go to point 1:53 and watch as the two guys go through the gate and up the hill (until about 2:12). You should see the video darken and lighten noticeable (thanks to the good old grey Irish sky!).
For me, this is a show stopper. It means I cannot watch videos at lower brightness levels, when the effect is more noticeable. It also means that when browsing web pages (which have white backgrounds), I am constantly seeing this contrast readjustment and it is very annoying and distracting. I really wish I was the kind of person who notice this kind of thing, as I'm sure quite a few may not. I am returning this otherwise fantastic tablet because of it.
Yes, I know this is my first post and will probably be deleted (you guys are strict!), but I've been reading about this problem here (there are plenty of threads) and in other forums and just wanted to add my voice.

I noticed this the other day whilst watching this YouTube vid in bed with the brightnes low.
http://www.youtube.com/watch?v=uMm9E8pGZ7M&feature=youtube_gdata_player
It'd be a little better if it was a subtle change, bithgening ad dimmming slowly rather than the abrupt increase/decrease in brightness. It'd be even better if it could be disabled altogether but at least I know it's not a fault with the TP and is in fact a feature.
Thanks for putting my mind at rest everyone, I'll live with the annoyance.

I also really wish this could be disabled. It is very very noticeable when watching anime. Keeps changing from bright and vibrant to dark and dull
Sent from my Transformer Prime TF201 using Tapatalk 2 Beta-5

Just a quick heads-up: In the Acer Iconia A510, also a Tegra3 tablet, this issue does NOT occur.
So it's not a hardware thing and Asus needs to fix this

Could the problem be the proximity of the light sensor near the screen? Maybe it's bleeding light into the sensor.

i myself is having this issue, and i see it constantly cause it affects my eyes alot, my eyes feel like its re adjusting to the dark and brighter setting when it happens so i notice it instantly, i really do wish that it would stop, cause its hurt my eyes at night when the screen gets brighter, i think its affected by whats being displayed on the screen, if something is really too bright, it dims it and if something is too dark it brightens it but for gaming and viewing movies that can get very annoying since movies and gaming changes scene very often.
Sent from my Transformer Prime TF201 using Tapatalk 2

Related

Prime low refresh rate screen

When I got my Prime I was like F yeah but after a few days, I've noticed that the screen seems to be sort of flickery. Not in the sense that it is actually changing colors but its like the effect on old crt tv's where when you wave your hand in front of it, your hand seems to have an afterimage. I am on ICS and have also noticed that the screen stops having this effect when on full brightness in super ips mode. I find this to be strange because I have a janky old ipad and it doesn't have this effect. SO, my question is this. Is asus using bad screens or old tech or is it a software bug? I believe it has something to do with the refresh rate of the screen.
Sent from my quadcore slab of cheese using xda premium.
Probably a SW issue. I don't have that on my prime n I'm on ICS also.
When on cyanogen, I saw an option to "decrease hysteresis". My evo 3d never had this problem so I never used it. I wonder if that could help.
Sent from my Transformer Prime TF201 using xda premium
jdeoxys said:
...but its like the effect on old crt tv's where when you wave your hand in front of it, your hand seems to have an afterimage.
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Click to collapse
Yep, I see it too. I can also see it when scrolling text on a webpage. My wife, however, cannot. So I think maybe some people are just more sensitive to this kind of thing.
I read somewhere while researching the prime that when in powersaver mode the screen refresh rate is dropped to 35Hz. This makes sense, I guess. But I couldn't really see any difference between powersaver mode and performance mode, so I don't know if this is a reliable report.
The refresh rate thing is slightly annoying to me but I can live with it, I guess.

[Q] SGS 2 - low light reveals screen defect?

There are a few threads out there that have touched on this issue but none as far as I can see that deal with it directly.
The problem comes when you display a pure black screen in low light conditions. It shows that the AMOLED screen is actually grey / blotchy / cloudy instead of being pure black. Initially I thought mine had fingerprints or smudge marks on it, until I realised they were behind the screen. I guess I might have got a phone with a screen that was replaced, but the amount of people who have also reported a similar issue leads me to believe that it might be a manufacturing default? The blotches / clouds on the screen dont change, but exhibit a random formation as one would expect from a defect. It is also possible to see a very faint outline of light running along 3 edges of the screen.
Naturally this is a situation that doesnt reveal itself very often. But I as I use my phone a lot at night, especially reading ebooks or watching films, you start to notice it more and more where you have large expanses of empty black screen.
What I would like to know is how many people have got screens that exhibit this behaviour and how many of you have sent them in for service or had them replaced?
Is it a common issue and something that is to be expected from this type of screen?
You can test if yours has this problem using 'Screen Test' (its free) from the market place. It cycles through solid colours and patterns every time you touch the screen.
Just do it in bed with all the lights out P), give your eyes a few seconds to adjust and see what your screen looks like displaying pure black.
I'm very interested in everyone's experiences and any input or information you have.
Thanks everyone in advance!
ps: I came from a ZTE blade (OLED) which has a uniformly dark grey background when displaying pure black. I kinda expect this as it is a budget phone (albeit with a better than budget screen), but I didnt expect the SGS2 to be quite as bad.
Use "screen adjuster" from the market and set contrast to -60
i have never seen this black low light screen defect. but i am asking you people if any of you have noticed that ugly blurry shadows which are perfectly visible with low light, on white backgrounds especially. they look like marks above the actual display and make high quality images look like low resolution.. it is annoying as hell..
I have this. Noticed it one night when my phone was switched off and charging.
Sent from my GT-I9100 using XDA App
I also have this, noticed the first evening i used the phone...you can notice this during the screen wake delay, or when in a call if you cover then uncover the proximity sensor...don't know if it's a defect but sure it bugs me, i know many won't notice it and will say they don't have this...i will add that if u look carefully to the screen dimmed at lowest brightness in a low light (buy not dark) environment, like early morning, you'll see some "interferences" behind the image, also the darker/yellower left half screen is still visible in these conditions
These things shouldn't be there in a 500€ phone
Sent from my GT-I9100 using XDA App
Thanks for the feedback already.
@elmerendeiro: I have also noticed some 'interference' lines on my phone from time to time. I did a bit of research and it seems when your phone's brightness is set around 25 - 30% it picks up interference from either the wifi or 3g radio. Notch the brightness either above or below this level and you wont see it anymore.
I agree with you when you say we shouldn't be having these problems on such an expensive phone.
It bugs me too - if it wasnt for this i'd have to say it would be an amazing phone
Might give the Samsung service center a call and see if its something they're aware of and if they are replacing screens with this problem?

An Observation

I've read of several owners complaining about how bright the lowest brightness is, and others (including myself) on the dark 'splotches' on the screen in very dark settings, only recently have I pieced the two together: Motorola purposely made the minimum brightness still very illuminated in order to try and hide these marks on the AMOLED screen. It's very annoying when these are visible, and it's even more annoying trying to read or accomplish any task in a very dark setting; the screen is still so bright that it hurts my eyes.
I hope Motorola fixes this hindrance in future iterations of the Razr/Droid series.
Sent from my DROID RAZR using Tapatalk
That makes sense
This makes sense. I too have noticed the dark splotches and I thought I was the only one who received a somewhat defective one. But for me, as long as I'm not looking at a super dark image in a super dark room I cannot notice them.
But thanks for the reassurance that I'm not the only one!
Does not make sense at all - how low would the brightness have to be to see those spots if they are only visible on black background in COMPLETE DARKNESS?
Yeah, you have just discovered America.
I have the same. I only see them when the phone is docked and in night clock mode, or when I'm running screen filter to cut the light when playing something in bed.
Never seen them. Not that big an issue if they're there.
Sent from my AXI0M ICS RAZR using tapatalk.
Szadzik said:
Does not make sense at all - how low would the brightness have to be to see those spots if they are only visible on black background in COMPLETE DARKNESS?
Yeah, you have just discovered America.
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If my brightness is set to minimum and it's nighttime, when watching movies, looking at pictures, or even just navigating around the OS, I can see them, they look like water-marks on the screen.
"you have just discovered America." Is that suppose to be an insult?

Anyone have both a TF101 and a TFP?

Does anyone have both the TF 101 and the prime? I had gotten a replacement from Asus, and I noticed the screen would wash out a lot more on an angle compared to my TF 101, So asus replaced it (the first replacement was a C30 and they replaced it with a C20 which actually has better wifi range than the C30 did) And I noticed again that the screen would wash out more when held on an angle than the TF 101 did. Now I dont think I got two primes with the same exact issue so now I'm thinking that maybe its just the way the TFP LCD panel is. So I was wondering if someone that has both a TF101 and a Prime if they can do a side by side and let me know. Put the same wallpaper on both devices, and also set the brightness to the same on both devices(I set them both to max, with IPS+ off on the prime). Does the prime get more washed out when held on an angle compared to the TF101?
Thanks in advance
Put the Prime in Performance Mode and then re-do your testing.
Its an auto contrast feature of the tegra 3. Seems to happen more in lower power modes. Search for contrast on this forum there posts about it but its a feature not a bug. Higher brightness and super ips mode are also ways to reduce it from happening.
Oh yea and the 101 didnt have this feature.
DX` said:
Put the Prime in Performance Mode and then re-do your testing.
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Click to collapse
I have it in performance mode and it still washes out more on an angle than my TF101.
indie13 said:
Its an auto contrast feature of the tegra 3. Seems to happen more in lower power modes. Search for contrast on this forum there posts about it but its a feature not a bug. Higher brightness and super ips mode are also ways to reduce it from happening.
Oh yea and the 101 didnt have this feature.
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Click to collapse
Thanks, I was looking at that but wasnt sure if it was the same issue. I do notice the TFP washes out a lot more on an angle even when in performance mode. Since I got two replacements that were like this I'm thinking more its just the way it was made. When asus sent me the first replacement and I noticed it(I dont think I noticed it on my original TFP) I took a video of it washing out more compared to the tf101 when viewed on an angle. I'm pretty disappointed.. I have never seen an IPS screen wash out like that. It washes out on an angle more than my HTC Evo View(flyer) and that's not even an ips or slcd screen
Here are the links of the videos of the first replacement they sent me. This new replacement washes out the same way on an angle
http://www.youtube.com/watch?v=YdQIbLpCLj4
http://www.youtube.com/watch?v=k_SIoyhUEVs
I have both, and don't notice any difference except the 201's screen is much sharper and way brighter. I hack the 101 with revolver, and have left the 201 stock. Just got the GPS kit, and now get more sats with the 201 indoors! Too bad the GPS kit doesn't have a power jack. My 201 is a BCOKAS.
If those videos are accurately showing what you're seeing with the device in-person, then I would exchange the unit again. Mine looks nothing like that. Like others have said, the viewing angles on my TF201 are just as good as on my TF101. I'd say the Prime's screen is an improvement in every way, and I thought the original Transformer had a very nice screen.
What you are seeing is Light Bleed, you can search in XDA how to fix it yourself (you have to open your Prime) or return it to Asus. That is not how the screen should look.
bedoig said:
If those videos are accurately showing what you're seeing with the device in-person, then I would exchange the unit again. Mine looks nothing like that. Like others have said, the viewing angles on my TF201 are just as good as on my TF101. I'd say the Prime's screen is an improvement in every way, and I thought the original Transformer had a very nice screen.
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Click to collapse
Yeah, thats the way it looks in person. I really doubt asus will replace it a 3rd time... I'm waiting to hear back from Hai Trat. I expected the viewing angles to be the same as well. when I wish I could remember if my first unit washed out.. I think I was too anal about the dead pixels it had to notice if that one washed out. But after getting the 1st replacement and the 2nd and both washed out like that and both were different batches (first replacement was a C3, 2nd was a C2) I figured maybe it was normal. Guess not..
Zephyrot said:
What you are seeing is Light Bleed, you can search in XDA how to fix it yourself (you have to open your Prime) or return it to Asus. That is not how the screen should look.
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Click to collapse
Nope, it's not light bleed. That unit does have some but the video shows it correctly, when viewed on an angle the whole screen clouds and washes out. And this is the 2nd one that has done this. My tf101 has some light bleed and doesnt do that at all. This 2nd replacement I have (the video is of the 1st one) the backlight bleeding isnt as bad and it still washes out like that on an angle.
Hmmm....Now that I do a direct side-by-side...in a dark room, with dark backgrounds on both tablets...I do see more of that "glow" that you're showing in your videos. The image is still crisp, but there is a distinct white-out, glow kinda thing going on. Maybe not quite as pronounced as your video, but that could just be lighting, camera, etc.
I probably wouldn't have noticed without doing the side by side video to see if I could show you how mine was OK, lol. LIke I said, the image and colors are still crisp, but there is a bit of that glow over the image.
I almost wonder if it isn't the oleophobic coating refracting the light. It's definitely not just general backlight bleed. My Galaxy Nexus (which also has an oleophobic coating of some kind) doesn't seem to exhibit the same off-axis behavior, but the screen is OLED, is much smaller, etc, so it's hard to make a direct comparison.
Your videos did seem pretty pronounced though. At this point I can't comfortably say one way or the other. I still think my screen looks great. I guess you just have to figure out if you're satisfied or not. In comparison to my TF101, I'd pick my Prime's screen every time.

PWM or backlight failure?

I'm experiencing either a defect or an unfortunate feature on this tablet. I just took delivery of a new one, and while viewing any solid colors besides grey on the screen everything is fine (also no dead pixels), but I'm noticing what appears to be slight backlight flickering/pulsing whenever grey or light blue is shown on the screen. It seems to be PWM (pulse width modulation) of the leds, but I can't be certain it's a defect or just the unfortunate way these tablets' led screens are designed. It's a very subtle but consistent and annoying pulse, but it's definitely there. Can anyone confirm that PWM is what's going on with these tablets or if this is a defective screen. The screen doesn't pulse at all on any other colors solid or only partially filling the screen or otherwise.
I haven't noticed anything on mine, though I tend to keep the backlight fairly low (17%).
One thought though which is why I'm saying anything, I remember on the nexus 7 there was an issue with one of the friction pins not connecting to the back of the case's antenna fully sometimes, which would cause the radio/wifi to suck extra power resulting in backlight pulses... have you tried turning on airplane mode (disable the cellular) with wifi off to see if that makes a difference? Though it would be odd if it only affected the one colour... I suppose it could be your ambient light source too, does it do it in sunlight?
joeblowma said:
I haven't noticed anything on mine, though I tend to keep the backlight fairly low (17%).
One thought though which is why I'm saying anything, I remember on the nexus 7 there was an issue with one of the friction pins not connecting to the back of the case's antenna fully sometimes, which would cause the radio/wifi to suck extra power resulting in backlight pulses... have you tried turning on airplane mode (disable the cellular) with wifi off to see if that makes a difference? Though it would be odd if it only affected the one colour... I suppose it could be your ambient light source too, does it do it in sunlight?
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Good idea! Unfortunately, killing the antennas doesn't affect it. And there's no ambient light sensor on the g pad x, so that's out as well I'm so disappointed because there are not dead pixels and only very little light bleed in the corners too.
I didn't mean ambient light sensor would be the cause, more that perhaps you have bulb/s that cycle at a specific rate at a certain colour range that would cause a subtle flicker, I always found those big long roof fixture fluorescent tube lights bad for this sort of thing... I notice some "out of the corner of my eye" subtle flickering on my PC LCD when I have the one CFL on, but not when I have the other LED lamp going instead for example. I just tried a LCD screen tester with various solid colours (cyan, blue) and the only 'flickering' I'm seeing is if I actually move the screen, this panel has some waviness in it that is visible when the screen is off and you angle it just right under a light which seems to pop out on these blues with the backlight turned up - but only when the screen is physically moving. Definitely not a perfect panel, but for me nothing like what you are talking about.
I'm outta ideas though, unless you are running a custom firmware and it does something different than what my stock does.
GL
edit:/ just read that RFD post from the other thread, and I definitely notice a flicker when in nova's app drawer. It seems to occur only right after I move the tablet and only noticeable at higher backlight settings, if I set it down flat and don't move it, it doesn't do it. Perhaps related to the gyro sensor? Something not isolated fully/properly would be my guess. With the wifi turned on, it also does it along with the activity up/down arrows on the logo... now that I've seen it I wonder if its going to bother me on lower brightness levels now :silly:
joeblowma said:
edit:/ just read that RFD post from the other thread, and I definitely notice a flicker when in nova's app drawer. It seems to occur only right after I move the tablet and only noticeable at higher backlight settings, if I set it down flat and don't move it, it doesn't do it. Perhaps related to the gyro sensor? Something not isolated fully/properly would be my guess. With the wifi turned on, it also does it along with the activity up/down arrows on the logo... now that I've seen it I wonder if its going to bother me on lower brightness levels now :silly:
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Thanks for checking. I tried the airplane mode setting, and I swear that fixed it. But then it came back after a few more toggles of data/wifi. Given that you're seeing it too and that others have reported seeing it as well in the RFD thread, I'm thinking it isn't a defect but rather poor design. There's little chance it would be this widespread and only on the exact same color combo for everyone. I think most people just never notice it since you're rarely just looking at a solid or mostly solid grey screen. I wonder if there's a way to disable the gyro on a stock/non-rooted gpad like mine? For me, it does it regardless of brightness level.
I've seen this on different devices too, so it's not just a G Pad X thing. I wanna say I've seen it on my Nexus 5 back in the day, but I've had many devices so it's hard to remember. But yep, noticed it happens on "grey" colors. It's much less noticeable with the brightness lowered. Never really bothered me so never posted about it.
emilyrugburn said:
I've seen this on different devices too, so it's not just a G Pad X thing. I wanna say I've seen it on my Nexus 5 back in the day, but I've had many devices so it's hard to remember. But yep, noticed it happens on "grey" colors. It's much less noticeable with the brightness lowered. Never really bothered me so never posted about it.
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Click to collapse
My guess is it's the led pulse width modulation. It affects some screens more than others, but is an issue with led implementation on lcd screens in general. I'm leaning towards keeping the tablet as I'm 99% convinced that another unit would exhibit the exact same behavior. Glad to hear it isn't a defect, but sad that they did not manufacturer a better screen.
Jottle said:
My guess is it's the led pulse width modulation. It affects some screens more than others, but is an issue with led implementation on lcd screens in general. I'm leaning towards keeping the tablet as I'm 99% convinced that another unit would exhibit the exact same behavior. Glad to hear it isn't a defect, but sad that they did not manufacturer a better screen.
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Click to collapse
I don't want to clutter this thread any further, but I'm going into a B&M t-mo store to see if I can test this out on a display device to confirm how widespread this issue is.
Quick update on the flicker issue. It's a problem with all the units, or perhaps just poor design. I did a warranty exchange, and the replacement unit had the exact same issue. Oh well. Just time wasted I guess.
I have the same exact issue with the one i got my mom. Fortunately it doesn't bother her too much but it definitely seems to be a design flaw as we also returned it with the return unit having the same issue
Welcome to the world of flicker.
What you are seeing is very common and an unfortunate side effect of cheap reference designs and a don't care attitude.
There are many new standards for flicker but I doubt they'll be implemented. Flicker pwm needs to be in the 10khz range to be indistinguishable to constant current drives.

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