Talk:Dot pitch

Diagram required?

{{Reqdiagram}}

Re: {{Reqdiagram}}:I disagree; ALL of the See Also links have diagrams or images already, and each illustrates an aspect. If anything, some of the articles should be merged, with the question being which ones. It doesn't have to be only two articles merged either; it could be 3 or maybe 4. I'd suggest revisiting the diagram question AFTER a merge discussion. --Scott McNay 06:56, 27 November 2006 (UTC)

I've commented out this template for now, if someone re-adds it they should add some detail about what diagram they are requesting. --pfctdayelise (talk) 12:45, 27 July 2008 (UTC)

Image

Noticed this article needed an image, so I went ahead and made one: http://commons.wikimedia.org/wiki/Image:Dot_pitch.png I hope it's good enough, and otherwise just don't use it, or tell me what to change on my talk page, no problem. Xilliah (talk) 23:20, 12 March 2008 (UTC)

I have removed it because it says "dot pitch" where it should say "pixel pitch". Eric Kvaalen (talk) 08:56, 2 May 2015 (UTC)

AG Pitch

Sony professional series monitors specify the pitch as "AG pitch". What is AG? Thx, Daniel.Cardenas 17:26, 11 June 2007 (UTC)

I would wager they mean aperture grille. — Aluvus t/c 17:28, 11 June 2007 (UTC)

table generator

The following was used to generate the table. If you want to add more resolutions or screen sizes, just add them to the source, compile and run.

import java.util.Vector;

class Resolution{
    public int horizontal;
    public int vertical;
    public Resolution(int horizontal, int vertical){
        this.horizontal = horizontal;
        this.vertical = vertical;
    }
    public Resolution(String res){
        this(Integer.parseInt(res.substring(0, res.indexOf('x'))),Integer.parseInt(res.substring(res.indexOf('x') + 1, res.length())));
    }
    
    @Override
    public String toString(){
        return horizontal + "x" + vertical;
    }
}

class ScreenSize{
    public double size; // inches
    public ScreenSize(double size){
        this.size = size;
    }
    @Override
    public String toString(){
        return String.format("%.1f \"", size);
    }
    
}

public class DotPitchCalc{
    public static void main(String args[]){
        for(int i = 0 ; i < args.length ; i++){
            System.out.println("args " + i + " " + args[i]);
        }
        Vector<Resolution> resVec = new Vector<Resolution>();
        
        resVec.add(new Resolution("1024x768"));
        resVec.add(new Resolution("1280x768"));
        resVec.add(new Resolution("1280x800"));
        resVec.add(new Resolution("1280x1024"));
        resVec.add(new Resolution("1440x900"));
        resVec.add(new Resolution("1400x1050"));
        resVec.add(new Resolution("1680x1050"));
        resVec.add(new Resolution("1600x1200"));
        resVec.add(new Resolution("1920x1200"));
        resVec.add(new Resolution("2560x1600"));
        resVec.add(new Resolution("3840x2400"));
        
        Vector<ScreenSize> screenVec = new Vector<ScreenSize>();
        
        screenVec.add(new ScreenSize(12.1));
        screenVec.add(new ScreenSize(13.3));
        screenVec.add(new ScreenSize(14.1));
        screenVec.add(new ScreenSize(15.4));
        screenVec.add(new ScreenSize(17.0));
        screenVec.add(new ScreenSize(20.0));

        // header
        System.out.println("{|class=\"wikitable\"");
        System.out.println(" |");
        for(ScreenSize s : screenVec){
            System.out.println(" |colspan=2| " + s.toString());
        }
        System.out.println(" |-");
        
        for(int i = 0 ; i < resVec.size() ; i++){
            Resolution r = resVec.get(i);
            System.out.printf(" | %9s ",r.toString());
            for(ScreenSize s : screenVec){
                double p = ppi(s,r);
                System.out.printf("|| %6.2f ",p);
                double d = dotmm(p);
                System.out.printf("|| %6.4f ",d);
            }
            System.out.println();
            if(i != resVec.size() - 1)
                System.out.println(" |-");
        }
        System.out.println(" |}");
    }
    // pixels per inch
    static double ppi(ScreenSize ss, Resolution res){
        // use the diagonal, compute the pixels that would be there, and divide by the lenth in inches
        return Math.sqrt(res.horizontal * res.horizontal + res.vertical * res.vertical) / ss.size;
    }
    static double dotmm(double ppi){
        return 25.4 / ppi;
    }
}

— Preceding unsigned comment added by 207.203.88.15 (talk) 21:04, 17 July 2007

Fine. The result however is pretty useless as it includes a multitude of resolutions that do not exist (and make no sense at all when trying to compare) and omits a number of actual possibilities. It is not properly formatted and it does not indicate laptop or destop version. It is computed and does not take into account that some pixel pitches differ between computed results and manufacturer claims (such as the 30 inch screens). I revert to my version. Agentbla ^(talk) 00:00, 18 July 2007 (UTC)

Not fine. It appears to be ORIGINAL RESEARCH/Content. The Table, as of Apr-12-2017 is HORRIBLE! One minor question I have is which countries which use Inches as units of measure of length also use the comma as the decimal point? The serious problems I have with it include: the units of measure are NOT designated. 1280 x 800 = 1.02 million pixels, NOT 1.01. The headings are not explained. I have no clear idea of what "Megapixel" means. The screen "size" is (apparently) its DIAGONAL size. Pixel Pitch is confounded with dot pitch. Which is it? Pixel pitch is explained as "In the case of an RGB color display, the derived unit of pixel pitch is a measure of the size of a triad plus the distance between triads." and used both in the table and the diagram. The article is about dot pitch, not pixel pitch. The title "LCD bigger than 15 inches" is wrong: the first entry is 15 inches (15 is not bigger than 15). The "Pixel pitch" for the 15" entry is "m". WTF?! If you're going to include a table on the "Dot Pitch" article is should (as anyone but a blithering idiot would understand) actually contain a column with the dot pitch. Also, the diagram of Pixel Pitch has the shadow mask spacing different in between (at least) the 1st & 2nd row compared to the 2nd & 3rd rows, and the between the last two rows. (Also what IS a triad? - 3 rgb dots in a (horizontal) line or in a triangle? Its meaning is ignored in the article, and yet the diagram relies on the concept. If the article is about dot pitch, then its subject should be dot pitch, not pixel pitch. Stating that pixel pitch is "derived from" two other things doesn't explain it unless you explain how it is derived. (I also wonder if the crude hexagonal packing of dots as depicted is universal, but I digress...). This article is outdated. The table appears to have entries for screen sizes which don't exist. The table ignores entries for other than rgb triad pixels. The table doesn't have entries for 4k, 5k, & 8k screen sizes and completely ignores TV screens .98.21.215.86 (talk) 17:39, 12 April 2017 (UTC)

Slot mask CRTs

What about slot mask CRTs? They're similar to aperture grille types but instead of uninterrupted vertical phosphor stripes they have pixels made of three short, vertical stripes surrounded by a rectangular hole in the mask, with no divisions between the three colors.

Dot Triad CRTs have a separate hole in the slot mask for every phosphor dot. Compare a TV with a dot triad CRT to one the same size with a slot mask and you'll notice two things. The slot mask one will have a brighter picture but it won't be as sharp because the glow from the three phosphor stripes in each pixel bleed together. —Preceding unsigned comment added by Bizzybody (talk • contribs) 08:12, 17 October 2007 (UTC)

Larger is better?

One part of the article says:

"...with a larger number meaning closer spacing. Closer spacing generally produces a sharper image..."

So that's saying that a larger number for dot pitch produces a sharper image. But then later it says:

"The smallest dot pitch at the current time is 0.099 mm -- this will ultimately produce an incredibly sharp image on the screen."

So that suggests that a smaller dot pitch produces a sharper image, contradicting the first part. I'm not an expert on this, but from reading the definition of dot pitch, it seems like neither of these two claims is always true. Dot pitch is the size of a triad plus the distance between the triads. For a given screen size and resolution, I think the triads themselves have to be larger to produce a sharper image, and the distance between the triads has to be smaller to produce a sharper image. Isn't that right? In any case, we should remove this contradiction from the article, or clarify it. Navigatr85 15:48, 2 April 2008 (UTC)

The first excerpt is refering to dot pitch as measured in dots per inch. The second excerpt is refering to dot pitch as measured in millimeters. The two measures are inversely related. Measurements in millimeters are much more common in practice for monitors. A smaller (in millimeters) measurement translates to a higher maximum resolution (more pixels in the same amount of space), which is basically what is meant by "sharper". Contrary to what is implied in the article, scanners and printers are usually described as having a "resolution" (measured in dpi) rather than a "dot pitch", although there is no fundamental difference. — Aluvus t/c 00:16, 3 April 2008 (UTC)

"Dot pitch may be measured in linear units, usually millimetres, with a smaller number meaning closer spacing, or in dots per linear unit, for example dots per inch, with a larger number meaning wider spacing." I have no expertise on this, but this seems wrong. Higher dots per inch means wider spacing?? In other words, the more dots you pack in a inch, the farther they are apart? Doesn't make sense. Would someone please explain? —Preceding unsigned comment added by 132.207.137.202 (talk) 15:36, 12 June 2008 (UTC)

And what is the max. dot pitch for the human eye?

What is the maximum dot pitch that makes sense for the human eye? I understand that it depends on how close you are to the screen. But let us say for 1. a smartphone (10cm) 2. computer screen (30 cm) and 2. a TV screen (two meters distance)? May be I miss something but this seems like an important subject for this article that is totally missing. Andries (talk) 20:00, 1 June 2010 (UTC)

That depends on the human! Myopic people or children can see smaller things than others. Also, some people have higher visual acuity. Eric Kvaalen (talk) 08:56, 2 May 2015 (UTC)

"Dot Pitch" and "Pixel Pitch" are NOT the same

Tristanlbailey (talk) 10:09, 23 July 2010 (UTC)

While the definition of "Dot Pitch" is described fairly accurately, the exception is the reference to "Pixel Pitch", which appears as an alternative term. This is incorrect, as the term "Pixel Pitch" actually refers to the size of pixels (in millimetres), and not of sub-pixels.

One example can be seen from a particular LCD module specifications document, by NEC: http://www.earthlcd.com/downloads/NEC%2010276AC2402.pdf

To clarify, Page 4 of the document has both "Dot Pitch" and "Pixel Pitch" values included in a table, where the "Dot Pitch" value (0.08mm (Horizontal)) is ⅓ of the "Pixel Pitch" value (0.24mm (Horizontal)) of the product. Also note that the vertical measurements are the same, suggesting that the sub-pixels are rectangular and vertically aligned, forming square pixels typical of LCD monitors.

This article also makes reference to "Pixel pitch" in one column of the "Common dot pitches in monitors" table, mid-way. Obviously, there is no "Dot pitch" column present. As I am not sure of how the table is constructed, I cannot make a recommendation of what change(s) need to be made.

The following quote should be either removed, or re-written:

"Traditionally, dot pitch in displays has been measured on the diagonal, as this gives the most accurate representation of image quality. Starting about the mid-1990s, however, some companies introduced a horizontal dot pitch as a marketing ploy [citation needed]. By measuring only the horizontal component of the dot pitch and ignoring the vertical component, even a cheap, low-quality monitor could be awarded a small-seeming dot pitch."

Horizontal dot pitches should not be seen as a marketing ploy, but instead as a more specific means of providing data to consumers. The change in trend from the use of CRT monitors (triangular pixels consisting of circular sub-pixels), to LCD monitors (square pixels consisting of rectangular sub-pixels), is perhaps what caused this misconception.

I have taken that out now. Eric Kvaalen (talk) 08:56, 2 May 2015 (UTC)

There may need to be a separate article created for "Pixel Pitch".

I think the whole premise of the article is wrong, dot pitch represents the ability to focus well it has nothing to do with the color raster as such. The beam is just peeing over the screen it doesn't care where those little color dots are and they are probably on a smaller scale than the focus anyway its two different worlds. — Preceding unsigned comment added by 87.195.131.153 (talk) 01:23, 25 March 2014 (UTC)

I have read over the entire article, and have come to the conclusion that the article needs a major cleanup. The article appears to be brief, and there are some aspects of the article that are misleading. The article in general should have more information on the topic, and be structured better. Upon review of related articles in other languages, it may need to be renamed with "Pixel Pitch"; there is a trend which suggests this may be more relevant to public interest. "Dot Pitch" could be retained in the renamed article, but under a specific section. Searches on "Dot Pitch" would need to be redirected to the "new" article. I will be adding "misleading" and "cleanup" templates at the top. If actual editing is prolonged, I may eventually edit the article myself, but not any time soon. I recommend that this be discussed, first. Tristanlbailey (talk) 05:39, 29 July 2010 (UTC)

Bigger vs Smaller

In principle, all other things begin equal, having more smaller dots (closer together) will produce a sharper picture than have larger dots further apart.

However, sharpness isn't really the goal - readability is. If you had a 14" screen that was 1920x1200, you'd have incredibly small dots incredibly close together. However, the resulting letters are so tiny that they're almost unreadable (I used to have a laptop like this, and it was awful). For any given resolution, a larger monitor is probably going to be easier to read than a smaller one, even if that means that the dots are bigger and further apart.

Purists will point out that you can simply change a setting in the OS and your characters will be drawn with more pixels, making them bigger while not losing any sharpness. In theory this is true - but in practice many applications (and even parts of the OS) will NOT handle this properly; often applications will have some parts sized out of proportion to other parts. Note that I'm not saying this should be the case; clearly it shouldn't, and any OS or application which doesn't handle this right is arguably deficient. However it IS the case - and in the real world users generally can't throw away their OS or their apps on a whim. Unless you have very unusual needs, I'd recommend NOT changing the OS's settings for this, because the downsides of the results outweigh the upsides.

So in practice, people should choose the resolution they want (which controls how much "stuff" they can show on the screen), and then get the biggest monitor that fits their constraints (price, deskspace, etc). The result will have a larger dot pitch than it otherwise might, but it will be easier to read. Obviously this could be taken too far: a 52" monitor running at 640x480 would look outrageously pixelated - but they don't actually make such things, so in a practical sense it's not a problem.

I'd hate for people to read things like "Closer spacing generally produces a sharper image" and use that as the criteria for purchasing a monitor, because in practice most people will be much happier going in the opposite direction - especially people of middle age and up whose eyesight isn't what it once was. —Preceding unsigned comment added by 74.166.109.199 (talk) 00:57, 8 January 2011 (UTC)

What setting can one change in Windows in order to affect the size of the letters? Theoretically, if you ask for, say, a 12 point font you should get letters whose "box" is 1/6 of an inch high, no matter what pixel pitch you have. The computer should simply use the right number of pixels. But it seems that this is not done. The letters on the screen are much smaller than they should be. Eric Kvaalen (talk) 08:56, 2 May 2015 (UTC)

Metric conversions

The use of imperial units is a headache for those of us who grew up on metric units and have no intuitive concept of imperial measurements. It's annoying to have to keep multiplying and dividing by 2.5 to get the screen sizes and resolutions into something understandable.

Recommend changing the table to give "Screen Size (cm (in))" and "Resolution (pix/cm (pix/in))".

So, this line:

1024×768 XGA 0.78 4:3 17.0 337 75.3

Would become:

1024×768 XGA 0.78 4:3 43.1 (17.0) 337 29.6 (75.3)

I don't mind having imperial units as an optional extra for Grandma, but they shouldn't be the only units in use on any article. Wikipedia is supposed to be a modern encyclopaedia, so we should be primarily using modern units (i.e. metric), not obsolete ones.

Roxor128 (talk) 07:23, 23 June 2015 (UTC)