Tuesday, May 10, 2011

" Pixel Density Propensity "

Once again I've come to the inescapable conclusion that everything is relative and so much of how we perceive things is simply a matter of "Perspective". Recently at work I was discussing video resolution with my old friend and prolific tinkerer, Randy "the Big unit" Messick  when it occurred to me just how ridiculous the size differential was between the 2 devices I currently use to view video content. That being an iPod Touch 4G and the recently purchased Viewsonic  PJD-7382 DLP projector.

Sometimes it's all in how you look @ the situation...(of course, you're probably still screwed)

The Touch 4G sports Apple's new "Retina" display with a 3.5 inch (diagonal) widescreen @ 960x640 resolution and an astounding 326 pixels per inch, while the Viewsonic is currently set @ 44 inches from the wall/ screen which produces an 84 inch diagonal image @ 1024x768 resolution (calculates to 15.24 ppi.). While the iPod seems a little on the small side for watching movies or tv, when placed 18 to 20 inches away it has the apparent "perspective" of a 27 inch television from across the room. Combine this with the extremely high pixel density and even my old "Internet Archive" movie downloads streamed via the "VideoStream" app look phenomenal on this thing.

Alrighty then, lets compare, iPod = 3.5 inches @ 326 ppi. versus Viewsonic = 84 inches @ 15.24 ppi.... Huh? How is it possible to have a giant image look that good @ such a low pixel density?  Answer... Perspective, or the distance of the viewer relative to the screen, buffered by a reasonable set of expectations. (if you expect everything to look as sharp as the iPod 4G, you'll be perpetually disappointed)    

Indeed, the calculation is correct @ approx. 15 ppi. on the Viewsonic...

Well, I guess we'll just have to take Apple's word for it....

By comparison here are some other devices and their display ppi.

Nexus One3.7 inches 800x480         252
HTC Evo 4G4.3 inches 800x480217
Palm Pre3.1 inches 320x480186
Kindle6 inches 800x600167
Zune HD3.3 inches 480x272167
iPhone 3GS3.5 inches480x320164
Macbook Pro 17"17 inches1920x1200133
iPad9.7 inches1024x768132
PSP4.3 inches480x272128
Macbook Pro 15"15.4 inches1440x900110
Typical 30" Monitor30 inches2560x1600101
Typical 20" Monitor20 inches1680x105099
Typical 24" Monitor24 inches1920x120094
Typical 46" HDTV46 inches1920x108048

Want to know how many pixels are in your display? (I was going to post the fairly simple formula, but stumbled across this nifty gizmo)
"Pixel Density Calculator"

 As for the Viewsonic @ 84 inches diagonal, well what can I say, "Hulu" at 480p is very nice and Call of Duty Black Ops on the Xbox 360 is "effing" spectacular, both by way of VGA inputs. Quite amazing considering the 84 inch image originates from a .55" DLP chip (yes, just over half an inch).
A few of you folks have probably heard me pontificate about what a gimmick "3D TV" is, and I stand by that statement, my current advice, if you already have an HDTV is, go HUGE and get a projector. While not a replacement for a television, a projector has considerably more fun/wow factor than any of the current crop of large 3D capable monitors and you don't have to wear the special image blurring "Migraine Glasses" to enjoy it.

A few "entry level" short throw projectors worth considering:
(XGA being the absolute minimum acceptable resolution)
Dell S300  DLP  WXGA (1280 x 800)

Viewsonic PJD7382  DLP  XGA (1024 X 768) 

BENQ MX613ST  DLP  XGA (1024x768)

Optoma GT720  DLP  WXGA  (1280x800)

However, there are a number of emerging technologies that will initially be used to enhance and improve the 3D experience, and I believe, will eventually eclipse it, tossing 3D into the dustbin of obscurity..... yet again.


Keep in mind that the above video is not actually streamed from YouTube @ 2564 FPS but is a compressed version running @ whatever frame rate they support, something more like 24 to 30 FPS. If viewed at the video's actual frame rate and native resolution this would look even more incredible... and require a considerable amount of bandwidth...
( the Blackberry @ 2:40 is really cool )

The second emerging standard is 4K resolution ( measured as horizontal pixels as opposed to the current vertical standard, 1080p ect.). Quad Full High Definition or QFHD doubles the current standard 1080p HD vertical and horizontal dimensions producing a 3840x2160 image. The extreme HD resolution, combined with higher frame rates will create an extraordinary video display so realistic it will appear three dimensional, a virtual reality experience...Although you'll most likely need new equipment to view QFHD @ it's native resolution, fear not, because it's still going to look great on you're standard HD display.

One consideration is that due to the limitations of the human eye, we're unable to discern the difference in the various HD resolutions past a certain distance anyway. Also in order to keep such large file sizes manageable, the video will be heavily compressed resulting in loss of detail and adding compression artifacts (video noise), so you're not seeing the original unadulterated image to begin with. In order to truly appreciate this hyper-resolution format you're going to need an extremely large screen and possibly an updated eyeglass prescription. The place to see the real hi-res stuff in it's original format along with a great 3D experience is still going to be at your local theater....(if they can stay in business that is)

YouTube's 4K video is best if viewed fullscreen @ 1080p (just pause until it loads...)

I can almost smell the wood shavings.....

Another positive direction 3D is taking, will harken back to Johnny Lee's Nintendo Wii VR head tracking concept ( Lee worked for Microsoft during development of the Kinect,...no surprise here). The latest developments in VR head tracking include using the "Kinect" device or even standard webcams with the head tracking feature. Below is Johnny Lee's excellent description of the Virtual Reality head tracking concept.

In addition, from Microsoft, (yes I said Microsoft) is this video of the future interactive displays and VR systems... There's quite a bit of neat stuff coming our way in the not too distant future.

The point here is, the "state of the art" keeps changing, improving, evolving and there's something in it for everyone. If you're one of those folks that has to have the absolute latest thing, you'll never be completely satisfied because an improved version of your new gizmo is coming out next month, for 100 bucks less. Being the technological "last kid on the block" has it's advantages. I learned this lesson the hard way after purchasing a Sanyo Beta VCR back in the day, and the VHS format became the freakin standard anyway. The younger folks that have an HD-DVD player laying around certainly understand this concept...

Our technology experience is whatever we make of it... and it's a total blast, even @  a mere 15.24 pixels per inch.

Sanyo Super Beta...20% Closer To Being Detached From Reality...

 Is the glass half empty, half full, or twice as large as it needs to be?.......


  1. I've had both a sony betamax and an hd dvd player. I wish the industry folks would decide on a common format before they start selling the crap to the public. I'm almost afraid to buy AV equipment anymore.

  2. I'm contemplating purchasing a projector and was wondering if you're planning a review of the viewsonic anytime soon?

  3. Sure, why not?... Give me a week or two and I'll cover the basics. Thanks for asking...

  4. This comment has been removed by a blog administrator.

    1. Thanks for your comment rahul, but it contained spam so it was removed.