Talk:Dot pitch

From Wikipedia, the free encyclopedia

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)

Contents 1 Image 2 AG Pitch 3 table generator 4 Slot mask CRTs 5 Larger is better?

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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)