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02-05-2012, 01:37 PM   #1
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Camera Screens, Dots vs Pixels

Can someone explain to me why whenever I see camera specs or reviews or whatnot, I always see their screen res written in dots and not pixels, am I missing something?

For example Pentax K-x has a 230k dot screen, why isn't this written as 320x240 Pixels? Is there is reason as to why dots is used instead of pixels? I mean when people say dots I think of printers since they are measured in DPI for their printing. Pixels makes a bit more sense for screen res really.

Also I see the high end cameras with screens of only 1000k dots (640x480 pixels), I would have thought these cameras would have the latest tech since they cost thousands. You can get 720p screens (2.3m Dots) which are on par with some EVF's (Same/Higher PPI on an average 3" screen), a high res screen would be ideal with cameras with no VF and you can get screens which perform well in sunlight aswell.

Just a thought ;3 (I have translated dots to pixels correctly right? o.O?)

02-05-2012, 01:43 PM   #2
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I always assumed this was to avoid people confusing the screen pixel size with the pixel size of the images taken by the camera.

This is just a guess.
02-05-2012, 01:47 PM   #3
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There are 3x as many dots as pixels. So ~921,000 dots is really ~307,000 pixels, which is a 640x480 VGA screen (that used on the K-01, K-5, K-r, K-7, and 645D), and so on.

QuoteOriginally posted by userage Quote
For example Pentax K-x has a 230k dot screen, why isn't this written as 320x240 Pixels?
Because the bigger number sounds better to the uneducated buyer

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02-05-2012, 01:50 PM   #4
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QuoteOriginally posted by Adam Quote
Because the bigger number sounds better to the uneducated buyer
That is actually what I first assumed

But Arnie also has a point, to someone who doesn't know what pixels are it can be quite confusing. (I think)

02-05-2012, 02:02 PM   #5
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QuoteOriginally posted by userage Quote
Can someone explain to me why whenever I see camera specs or reviews or whatnot, I always see their screen res written in dots and not pixels, am I missing something?

For example Pentax K-x has a 230k dot screen, why isn't this written as 320x240 Pixels? Is there is reason as to why dots is used instead of pixels? I mean when people say dots I think of printers since they are measured in DPI for their printing. Pixels makes a bit more sense for screen res really.

Also I see the high end cameras with screens of only 1000k dots (640x480 pixels), I would have thought these cameras would have the latest tech since they cost thousands. You can get 720p screens (2.3m Dots) which are on par with some EVF's (Same/Higher PPI on an average 3" screen), a high res screen would be ideal with cameras with no VF and you can get screens which perform well in sunlight aswell.

Just a thought ;3 (I have translated dots to pixels correctly right? o.O?)
because dots are absolute measure, one pixel need more then one dot and pixels can be misleading depending how the manufacturer counts them, read this: MicroOLED promises even greater electronic viewfinder resolution: Digital Photography Review

and this: Pixel density - Wikipedia, the free encyclopedia

Calculating PPI of camera screens

Camera manufacturers often quote camera screens in 'number of dots'. This is not the same as the number of pixels. There are 3 'dots' per pixel, red, green and blue. For example, the Canon 50d is quoted as having 920,000 dots.[9] This translates as 307,200 pixels (x3 = 921,600 dots). This translates to the screen actually being 640480[10]
02-05-2012, 02:11 PM   #6
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I understand more than enough about pixels and screens.

How can manufacturers count pixels differently? When they count them they don't count each sub pixel, they count the pixel as a whole.

Using dots means they include in each sub pixel in the count. Some screens have 2 green sub pixels for each pixel (Pentile screen) so by using dots they would have a larger number since they would include the extra green as another 'dot'. Using dots is very misleading.
02-05-2012, 03:18 PM   #7
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QuoteOriginally posted by userage Quote
I understand more than enough about pixels and screens.

How can manufacturers count pixels differently? When they count them they don't count each sub pixel, they count the pixel as a whole.

Using dots means they include in each sub pixel in the count. Some screens have 2 green sub pixels for each pixel (Pentile screen) so by using dots they would have a larger number since they would include the extra green as another 'dot'. Using dots is very misleading.
actually the opposite is true because the dots number is an absolute measure you either have or not have given number of dots they are physical dots and you can count them one way only, and exactly the Pentile screen claims more pixels, if you read the posts in the link I have provided you will see this:

"number of "pixels" is prone to trickery, as Samsung Galaxy S owners should know best - in that screen, Pentile GRGB pattern is marketed as 800x480, ie standard Android hi-res screens of it's days, but unfortunately, unlike traditional full-RGB pixels, they have conveniently (for them) counted each RG, BG pair as a full pixel. So, the stated resolution was in fact "algorythmic, sub-pixel rendering" BS resolution, and the actual, physical number of "dots" was significantly lower (and perceived visual sharpness, too), than competing traditional RGB LCDs of the day."

So showing the dot number is fair and claiming some pixels from the dots can be misleading depending how the manufacturer do the math.

Nothing about the bigger number - dots simply show the actual physical dots, the resolution claimed in pixels is prone to the manufacturer claim and 2 displays with same resolution can have completely different dots number.

The quality and the sharpness of the LCD screens so far depends on dots number. The resolution is relative. If you want to compare apples with apples look for dots. This is the reason most of the manufacturers show dots number.

Last edited by Wolfie665; 02-05-2012 at 03:29 PM.
02-05-2012, 03:53 PM   #8
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QuoteOriginally posted by Wolfie665 Quote
So showing the dot number is fair and claiming some pixels from the dots can be misleading depending how the manufacturer do the math.
Yes, if a manufacturer lies about the number of actual pixels, it is misleading, but discussing dots is also misleading unless the manufacturer (prominently) discloses how many dots per pixel.

The biggest problem is that the unscrupulous and uninformed will advertise camera screens in pixels when they mean dots. If dots were left out of it, it wouldn't be misleading, would it? That's where the bigger number becomes appealing to them, and how they abuse it.

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