Question On The Implementation Of Screen Backlight Adjustment In Modern Laptops

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Clamibot, Jun 13, 2020.

  1. Clamibot

    Clamibot Notebook Evangelist

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    This has been a question that has been bothering me for quite a few years, and no amount of google searching has ever yielded any answers. I think this is a good place to ask as you can basically post anything in this section of the notebookreview forums.

    So my question to any knowledgeable hardware people out there is: why is it no longer possible in modern laptops to adjust the screen brightness while in the BIOS? Laptop screens are basically light cannons nowadays when bringing up the BIOS screen and I have to wear sunglasses to keep the screen from searing my eyes.

    I remember that with my first two laptops, a Dell Latitude D620 and a D630, you could use FN+Page Up or FN+Page Down to adjust the backlight intensity no matter what. I used these laptops as hackintoshes, and it didn't matter what OS you booted into or if you were in the BIOS screen. That keyboard combination would always adjust the backlight intensity. Now that I think of it, I never saw a popup graphic telling me how bright the screen was relative to the maximum setting either, in either Windows or OSX. This leads me to believe that backlight intensity was hardware controlled in older laptops.

    In newer laptops, it is impossible to adjust the screen brightness in the BIOS screen when using the keyboard combinations for backlight adjustment. It just doesn't work. Laptops always boot up at either 50% backlight intensity or 100% depending on the vendor (this is anecdotal, I'm not sure if those are the actual percentages, but it's really bright and sears my eyes). Why is this? Was hardware controlled backlight intensity replaced with software controlled backlight intensity in the OS? If so, is there still any way to have modern laptops boot up with screen brightness level at minimum (this is the only setting comfortable for my eyes)? My Alienware 17 Ranger is the last laptop I can do this with, and I can only do it with the legacy option ROM enabled in the boot settings.

    Thanks in advance for your replies! I've been looking for an answer to this for the past decade or so.
     
  2. Fishon

    Fishon I Will Close You

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    If fifteen seconds or so of boot time really that annoying? Just look away from the screen? It's a fair enough question, but after the why it doesn't, just deal with it, no?
     
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  3. Clamibot

    Clamibot Notebook Evangelist

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    That's exactly what I do. It's not so much the boot up that's annoying, it's whenever I go into the BIOS to make changes to settings. For boot up, I just look away form the screen as you said. Not a big deal. Easy solution. However when I want to make setting changes in the BIOS, I gotta have those sunglasses ready or there's no way I'll be able to look at the screen.

    This is a problem with newer laptops, and I really shouldn't need sunglasses to make setting changes in the BIOS. I don't do that every day, but regardless, I shouldn't have to ever wear sunglasses to be able to look at the screen. Pressing the keyboard combination for dimming or brightening the screen within the BIOS does absolutely nothing on modern laptops, but it worked on older ones. I never had this problem with older laptops since the backlight adjustment worked outside of an OS. I'm just wondering why backlight adjustment no longer works anymore outside of an OS in modern laptops.

    Again, it's more of an annoyance than a problem. My sunglasses are a really good pair, so it's a good workaround, but I never had to do this with older laptops.
     
  4. JRE84

    JRE84 Notebook Deity

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    i dont go into the bios more than twice a year....what exactly are you doing in the bios all the time....sounds bizarre
     
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  5. Tinderbox (UK)

    Tinderbox (UK) BAKED BEAN KING

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    I have seen a option in some uefi bios to set a screen brightness level, Though i have never tried it as you did not want to take the chance of a blank screen on boot and not being able to see anything to fix it.

    In some older notebooks you were able to adjust the brightness outside of windows which was handy when you are running a ram/memory checker that could take over an hour to comple and you did not want the screen brightness to be at 100% that leanth of time.

    I would just accept the brightness for the short time and not mess around.
     
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  6. Clamibot

    Clamibot Notebook Evangelist

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    I mess with CPU multipliers and voltage settings quite a bit. I don't do it every day, but sometimes I feel like pushing my machine further. Gotta find that absolute best overclock man :D.

    I thank you all for your replies so far. You've expressed concern and have warned me against doing something stupid, but the question is more of why adjusting the backlight intensity is no longer possible outside the OS in modern laptops. That's what I'm looking for an answer to. As I mentioned before, this was possible in older laptops, but not in modern ones. My question is why.
     
  7. Meaker@Sager

    Meaker@Sager Company Representative

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    The control will likely be driver abstracted now rather than run direct in the bios.
     
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  8. Clamibot

    Clamibot Notebook Evangelist

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    Thank you very much. This was the answer I was looking for.

    I'm assuming it's now impossible to adjust backlight intensity outside an OS aside from the fringe case where the BIOS gives such an option.
     
  9. Meaker@Sager

    Meaker@Sager Company Representative

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    Pretty much in such a system where there is no hook in place.
     
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  10. Nick

    Nick Professor Carnista

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    Install a faster SSD so it boots in 5 seconds. Seems like a fair compromise.
     
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