Craig Birkmaier wrote:
Lot's of interesting data points in this story.
Of particular interest:
According to the research firm iSuppli, the average retail price
of 42-inch HDTVs - one of the most popular sizes this year - has
declined to $1,522 from $1,844 last Christmas, an 18 percent
drop.
(Note: 42" sets have the ability to deliver resolution
approximately equal to 480P, which is well matched to standard
definition DVD).
42" sets start to appear smallish in huge stores like Best Buy or
Costco. But in a typical den or living room, they are quite huge.
Let's do some realistic numbers. The screen of a 42" 16:9 set is 20.66"
high. If we watch the TV at 5 picture heights viewing distance, that's
8.6' away. So I think that's a realistic sitting position in may rooms.
Almost 9'. Some would say that's too generous.
Human vision corrected, if necessary, to 20/20, should be capable of
perceiving 1 arcmin of angular separation:
http://en.wikipedia.org/wiki/Visual_acuity
http://www.ndt-ed.org/EducationResources/CommunityCollege/PenetrantTest/
Introduction/visualacuity.htm
http://webvision.med.utah.edu/KallSpatial.html
Assuming the model is this simple, which I don't think it is, what does
an SD, ED, and HD set with 42" screen offer, if viewed from this 8.6'
distance?
SD 480i (or 312 effective): 2.2 arcmin. Obviously, this can be improved.
(Interlace factor 0.65.)
ED 480p: 1.43 arcmin. This can also be improved.
HD 720p: 0.95 arcmin. Just barely over the limit.
HD at 1080i (or 702 effective): 0.98 arcmin. Almost identical to 720p.
HD at 1080p: 0.64 arcmin. Overkill. But now you can move in to 3.5
picture heights, or 6' viewing distance for a 42" set, and now you will
be right at 0.91 arcmin. Just about right. Slight overkill.
So, a 42" HD set should be good for viewers who do not live in a
McMansion.
