Recently, I read an article about an exploratory effort in Japan by NHK to develop a new higher resolution television system.  The NHK Super Hi-Vision system is designed to deliver images with 8K x 4K resolution with a 16:9 aspect ratio.  As explained in the article, the objective is to be able to have a 100-inch display and not have the individual pixels be visible from a distance of one meter.  Wow!   Will we really be able to appreciate such spectacular images given that the current HDTV system is already better than the practical resolution of film images we have become so accustomed to seeing in movie theaters?   Pondering this led me to contemplate the broader question of whether there are limits when we no longer have the need or desire to push for further improvements – or perhaps the product is already so good for its intended purpose that we will not pay for anything better.     

Perhaps we can gain a useful insight or two by taking a look at what has happened in other technology areas?  Film cameras reached their practical limits of resolution many years ago.  Some of the lenses from the 1930s and 1940s achieved resolution levels as good as anything that is available from “modern” optics.  Instead of pushing for further refinements in resolution, lens designers found a more receptive market for added features such as variable focal lengths (wide angle and telephoto “zoom” lenses), larger apertures, and auto-focus.  In trying to balance between versatility and resolution, it was not uncommon to actually have the resolution get sacrificed to some degree.  The camera makers learned where the optimum balance was between film resolution, lens versatility, and manufacturing cost.  That led to many years of products being introduced that continued to be improved in many aspects, but lens resolution was not one of them.   Thus, today, most images taken with professional quality 35-mm film cameras fall short of the equivalent of HDTV resolution.  For those professional photographers who need to produce higher quality photographs for use in glossy magazines or for art gallery displays, a niche market developed using larger film formats such as 2 ¼ square or 6×7 cm.   A technology asymptote was achieved and sustained for many decades.  

Let’s now look at a more recent but closely related example.  Some years ago I wrote a column predicting that two megapixel imagers would be sufficient for digital cameras since they would produce images of comparable quality to 35-mm film.  Clearly, I was too conservative in my prediction.  To get to the 2 megapixel number, I was trying to balance what I estimated to be acceptable picture quality with the capacity of storage devices available at that time.  I did not anticipate that the camera makers would get into a “horsepower” race to see who could introduce a camera with the next higher megapixel number.  Fortunately, the cost of storage continued its rapid drop so that the huge image files that resulted from the 5 – 10 megapixel imagers are no longer all that difficult to manage.  But the pixel count race is also finally reaching its technology asymptote.  We seem to be settling on 10 megapixels as the magic number for “good enough”.  That is sensible since the lenses that are sold with those cameras are marginally adequate to fully utilize even this image resolution.   

In other areas of electronics, we have seen similar technology asymptotes come to pass – often with frustrating results for product manufacturers and resellers.  Consider, for example, the market for audio components.  Audio signal reproduction has become so precise and distortion free that it is no longer possible to hear the difference between many of the system components such as amplifiers, tuners, and CD players.  Speakers, as electromechanical devices, have not yet been able to achieve such perfection, but the end result has been that about the only way to distinguish products is on their styling, audio power output, and price.  Since we can no longer hear the difference, and because profit margins on these components are now so small, many resellers have adopted shady practices to increase profits – such as selling connecting cables and speaker wire at exorbitantly inflated prices with the claim that these accessories will bring out the “full audio capabilities” of the system. 

In the mid-eighties, we were introduced to the first personal computers.  The IBM PC and the Apple II gave us our first glimpse into a future that would soon be upon us.  The IBM PC and it’s clones had a clock speed in the vicinity of 10 MHz and a hard disk that could store about 20 Megabytes.  Not so many years after that, we were introduced to desktop computers with 100 MHz clock speed, then 500 MHz, and then the magic 1 GHz number was achieved.   There were plenty of predictions for when we would see 10 GHz clock speeds and beyond.  Having started my career as a microwave engineer, I knew how difficult life can get as one tries to work with signals in the many GHz range.  Well, sure enough we made it to about 3 or 4 GHz and then life got really difficult – we hit the wall.  The speed race ended and we were forced to switch over to multi-core processors to continue to increase computational capabilities.  Now the race is on to see who can introduce the next highest number of cores.  And in fact, we never even achieved the 3 or 4 GHz operation.  That speed is only for the arithmetic unit within the core of the processor.  The information that is swapped in and out of memory is typically at speeds of well under 1 GHz.  So again we have approached and reached a technology asymptote. 

It seems that with every product and every technology there comes a time of either “good enough” or that further increases are so difficult and/or so expensive to achieve — or are of such marginal benefit — that it is commercially prudent to develop other interesting capabilities instead.   I would suggest that we have come to such a time in the capabilities of desktop and laptop computers.  For a number of years now, we have been stagnant in our use of personal computers as word processors, spreadsheet manipulators, and for the preparation of presentations.   What has evolved instead is that we are now using our computers more as communication and storage devices.  That would lead one to conclude that Windows is a mature product of limited future usefulness.  So why is it still growing and producing major profits for Microsoft?  It appears that along with the concept of technology asymptotes, we also need to explore the concept of “technology momentum”.  We will do that in more detail in next month’s column.  Specifically, we will look at what keeps technologies going even after they seem to have lost their predominant position and why new entrants find it so difficult to unseat an incumbent technology.     

To return to our own field of display technology, can we say when we will have achieved the technology asymptote for display resolution?  Are we really going to be watching 4K x 8K displays in our living rooms anytime soon?  Even NHK admits that their effort is for the long term.   Since it took about 30 years to develop and implement the current HDTV standard, they are similarly thinking long term — several decades out.   But other than for special entertainment applications there is no assurance that we will ever see such high-resolution displays in our homes – even in 30 years.  We may find it more interesting to add other features and leave the resolution about where it is with HDTV.   We may have already reached the technology asymptote for display resolution. 

Are we there yet?  Is 1080×1920 resolution with 256 levels of gray for each color the final frontier for home entertainment?  If you don’t agree, then where do your think it is?  I welcome your comments on this topic or others.