There is little doubt Apple is working on a new iPhone (WSJ); it is dubbed the iPhone HD. Hon Hai Precision (Foxconn) will be manufacturing it, like it has all previous iPhone models. When is it coming? No one knows but it is expected to be announced on Tuesday, June 22nd. (There is also mention of a CDMA-based iPhone.)
The name iPhone HD might lead to speculations that we might see a 1280×720 pixel format on a 3.5-inch display. From a purely hardware point of view in order to properly be called HD requires the display to sport at least a 1280×720 pixel format. Unfortunately the term HD has been defined that way. In reality HD is not solely dependent on the number of pixels. Resolution as it relates to displays is a term that refers to pixel density as in PPI (Pixels Per Inch). I do not know how we got to our current situation where we equate 1920×1080 to resolution, but that is utterly incorrect and I am not even being remotely picky. When people start saying that an apple is blue someone has to become the idiot among the masses and start saying that an apple is red (or green). Hopefully over time the idiot will be proved right. So back to resolution: it is a term for pixel density, not pixel format. And resolution relates to determining whether or not our eyes perceive HD-quality more so than pixel format. (There is also the matter of distance from the viewer to the display, but we won’t get into that discussion here.)
Pixel Density: Some consider Apple’s displays to have low resolution compared to its competitors especially when it comes to notebook PCs. For instance, the high-end 13.3-inch MacBook Pro sports the same pixel format as the low-end version at 1280×800; there are no other options for the display. The corresponding pixel density, or resolution, is 113.49 PPI. (I used a nifty PPI calculator online.) Lenovo’s X300, a direct competitor to the high-end 13.3-inch and the MacBook Air has a 1440×900 pixel format with a 127.68 PPI. Here’s another example: the 15.4-inch MacBook Pro has a 1440×900 pixel format and a resolution of 110.27 PPI. Compare this to Dell’s Studio XPS 16 that has a 1920×1080 option on a 15.6-inch display resulting in a resolution of 141.21 PPI. These are big differences in resolution. But do note that Apple has been keen to keep the resolution at around 110 PPI for many of its displays. For instance, the new 27-inch iMac sports a 108.79 PPI resolution. Apple has done that to provide a consistent viewing experience across its displays. Two notable exception are the 17-inch MacBook Pro with 133.19 PPI and the 164.83-PPI iPhone/iPod touch, which brings us to the topic at hand.
iPhone HD: If in fact the next-generation iPhone sports the HD suffix that would retroactively mean that current iPhones (first gen, 3G, 3GS) do not muster enough resolution (PPI) and therefore is not HD class. So what is HD class? I do not know if there is a set definition anywhere, so let’s look at other smartphone manufacturers and find out. Although there is no HD tags associated with Motorola’s Droid, I think it might be considered the smartphone with the best HD-class display: a 3.7-inch TFT LCD with a 854×480 pixel format and a 264.77 PPI resolution. That is an incredibly high resolution! The display on HTC’s HD/HD2 smartphone is also highly regarded with a 4.3-inch LCD, a 800×480 pixel format and a 216.97 PPI resolution. These are just two examples but are examples of two of the best in terms of displays. Although the pixel format is of interest pay more attention to the PPI: they are well above 200 PPI. So it seems if Apple wants to play in the HD space it will need to equip the iPhone HD with at least a 200-PPI display.
600×400: Most likely Apple will keep the overal dimensions of the next iPhone intact. The display size will probably be unchanged at 3.5-inch. Keeping the same aspect ratio of the current iPhone at 3:2, a 3.5-inch display with a 200-PPI resolution translates to a pixel format of at least 600×400. A pixel format of 600×400 feels quite anti-climactic. I want it to be more. The company is aware of the competition and it cannot lag too far behind but Apple is concerned more about the entire system, the entire user experience. The 600×400 pixel format is simply a guess as it relates to the 200 PPI minimum requirement that seems to be at play in the HD smartphone game. Of this I am certain: the viewing experience on the iPhone HD will be thoroughly HD.