A followup to
this previous writeup about the 3DS XL marketing. Zolani13 brought up a few things via comment there that warrant clarification. The major points of contention, in summary: It is a matter of perception that people focus on either the diagonal measurement of a screen or the square, viewable area, and so Nintendo is accurate in its marketing claims; and that the dot pitch measurement was not illuminated adequately to criticize the picture quality.
For convenience, this is the chart that contains any figures referenced.
The diagonal measurement has been used consistently across all types of consumer displays for both marketing and specification sheets for over 60 years. It was originally so because of the physical architecture of CRT displays, but made its way into the LCD generation for two reasons: It is a simple way to express the size of a display, and by the time LCDs came onto the mass consumer market, it had been the de facto standard of screen measurement for 40+ years.
I don't think it an exaggeration to say that it is the single number most commonly associated with a display's size.
In point of fact, on following up with some light research across manufacturers, display area (width x height) is not published at all – neither in ads nor technical specifications. The only information given in every case is diagonal size and aspect ratio, complemented frequently by height and width, and other irrelevant details of performance. That it must be mathematically determined by the end-user exposes its severe disuse. (I scanned through information from Samsung, LG, Sony, Google [Nexus 7] and Apple to arrive at this conclusion; even Apple's extensive evangelism of the Retina display failed to report viewable area.)
The point is the deception and obfuscation of the truth on display here, and the media outlets who repeat it as Gospel to their readership/viewership without a second thought. The improvement in
published specifications is not 90%, so finding and advertising a 90% increase is misleading at best.
For what it's worth, we would not be having this conversation if Nintendo's marketing had stated “90% more viewable area.” I suppose that lacks the brevity and punch of “90% bigger,” though.
As to Zolani13's latter point – that the 3DS XL screen lacks in quality is readily apparent by the nature of using the same resolution stretched up to a larger screen. More space has to be filled with the same amount of visual data, and so that data is degraded, however slightly. Whether pixels are stretched to fill the space or there is more space between them, or both, the picture quality is objectively worse. Perceptions will vary (as they frequently do) on the degree. I personally don't think this is a dealbreaker for anyone. Not even 15 years ago a dot pitch below 0.32 mm was considered very good in high-resolution monitors. I only included it because it was trivial to do once the other numbers were generated, and for the sake of completeness of the comparison.
The calculation of dot pitch is simply the diagonal measurement, in mm, divided by the diagonal pixels (hypotenuse of Pythagorean theorem where the sides are vertical and horizontal resolution). It is standard to express this distance in mm, due to the scale of the measurement. 0.0076 inches is a bit unwieldy. I admit that it may not be absolutely precise, because I lack a physical sample as well as the pixel analysis equipment to do a proper measurement. If it makes you feel better, we'll call it 0.27 ± 0.01 mm to cover any potential variance.
There is precedent for being concerned about screen sizes in advertising. Several class-action
lawsuits were brought against PC manufacturers in the mid-90's over screen sizes advertised, versus the sizes delivered. More recently, in 2010, the San Diego County District Attorney along with 6 other California counties
settled a case with LG, Panasonic, Samsung, Sharp, and Sony over “misstating the screen size of flat screen televisions.” Cases like this are largely the reason that many LCD displays are now marketed in size “classes,” with actual viewable size stated in the finer print.
Manufacturers will stretch the truth as far as they can, until consumers or consumer advocates push back and challenge the accuracy of their claims. You may not always be right, but you're never wrong to ask.