# Solved: Monitor Contrast Ratio - What does (ACM) actually mean?



## LoveGoldens (Sep 23, 2008)

Monitor Contrast Ratio - What does (ACM) actually mean? I was told that it's a "marketing gimmick," but just how? 

I searced wiki.com and could find no explanation. I searched all over these forums, and still couldn't find it.

My monitor advertises 40,000:1 Contrast Ratio (ACM). I want to understand this issue.


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## BG-0 (Jan 1, 1970)

Adaptive Contrast Management. It's basically.. 75% marketing gimmick. There's the _"real"_ contrast ratio mentioned in the specs too, and the ACM is the virtual contrast ratio value that the monitor can resemble through the use of unexplained technologies.


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## LoveGoldens (Sep 23, 2008)

BG-0, Thanks!

Does 40,000:1 (ACM) convert to 4000:1 "real" CR (arithmetically)?

My monitor's manual or the box it came it does not include any 'specifications" showing the "real" value.


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## BG-0 (Jan 1, 1970)

It does not. The ACM and DC/CR are not relevant in any way.


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## LoveGoldens (Sep 23, 2008)

Ok. Thank you. Just one last question...

Exactly how can I find out what the real CR is for my monitor (Acer: H233H - HD)?

Acer's web site offers no such number, and their Tech Support staff act as though they don't understand the question!


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## BG-0 (Jan 1, 1970)

No idea. If it's marketed by "false" specs, then I guess there's no telling what the real ones are. Why do you want to find out? There's no revelance between the CRs of different brand monitors, so it's nothing to use for comparison either...


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## LoveGoldens (Sep 23, 2008)

BG-0 said:


> No idea. If it's marketed by "false" specs, then I guess there's no telling what the real ones are. Why do you want to find out? There's no revelance between the CRs of different brand monitors, so it's nothing to use for comparison either...


Am I wrong in assuming that CR exists on all monitors? I just thought that my monitor would have a ratio too, since that is a hardware manufacturing parameter.

I also thought that the higher ratio contrast values would display better quality on the screen. In my mind, it's equivalent to viewing a jpg or bmp image in 320x240 compared to viewing the same graphic with resolution of 1920x1080.

Obviously, I don't understand why there aren't any HARDWARE SPECS (on my monitor) that specify true Contrast Ratio.

Thank you for your reply.


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## BG-0 (Jan 1, 1970)

CR does exist on all monitors. It's just up to the manufacturers, or whoever wants to, to somehow measure it. 

BTW, just noticed that the monitor has a dynamic CR of 40,000:1, the ACM is just an image quality enhancement technology. 

High contrast ratio gives better image quality, this is however void if there's bleeding, ghosting or whatever else bad in the image. But the "betterness" is mainly, well, better contrast. Dark areas are strong black, light areas are actually light and luminating. 

As to why there isn't the actual CR in the specs... Maybe Acer just doesn't want to reveal that, for a reason or antoher. Maybe throw 'em with an email and ask?


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## LoveGoldens (Sep 23, 2008)

Thanks, BG-0. You helped by answering my concern.

I'll mark this topic as SOLVED.


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