Feeds

How to choose the right screen size

Is your telly too small - or too big - for HD?

Beginner's guide to SSL certificates

The maths bit

That all assumes the 2.7m viewing distance - if substantial numbers of people really are viewing HD sets much closer than that, perhaps the BBC will need to rethink the decision to broadcast its HD programming at 1440 x 1080 rather than a full HD.

Panasonic

Glasses won't help if you're too far away...

Not everyone’s watching BBC HD, and for many of us, an HD TV is also something to use with games, or for watching Blu-ray and other high definition content. And the real question, rather than ‘what resolution do we need to broadcast’ is ‘how far away should I sit from my TV?’

If you’re interested in working out the answer to that question, it’s not that difficult. I’ve made some assumptions here, chiefly that you have good or corrected eyesight, and that your TV set has an aspect ratio of 16:9.

In fact, the important measurement is really the height of the picture, or H. For a 16:9 screen with a diagonal picture of size D, you can calculate H using Pythagoras:

Formula 1

The generally accepted figure for human visual acuity is one minute of arc, so we need to calculate the distance at which one pixel is equivalent to that.

The simplest way to approximate this is with a triangle where the vertical side is the height of a pixel, p, and the other sides are of equal length. Bisect that triangle at the centre point, and we have a right angle triangle, with the angle at the eye equivalent to 30 seconds of arc, and the distance to the eye is d. A bit of basic trig gives us our next formula:

Formula 2

Internet Security Threat Report 2014

More from The Register

next story
Nexus 7 fandroids tell of salty taste after sucking on Google's Lollipop
Web giant looking into why version 5.0 of Android is crippling older slabs
All aboard the Poo Bus! Ding ding, route Number Two departing
Only another three days of pooing and I can have a ride!
Heyyy! NICE e-bracelet you've got there ... SHAME if someone were to SUBPOENA it
Court pops open cans of worms and whup-ass in Fitbit case
Official: European members prefer to fondle Apple iPads
Only 7 of 50 parliamentarians plump for Samsung Galaxy S
Fujitsu CTO: We'll be 3D-printing tech execs in 15 years
Fleshy techie disses network neutrality, helmet-less motorcyclists
Space Commanders rebel as Elite:Dangerous kills offline mode
Frontier cops an epic kicking in its own forums ahead of December revival
The IT Crowd's internet in a box gets $240k of crowdcash for a cause
'Outernet' project proposes satellite-fuelled 'Lantern' WiFi library for remote areas
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Getting ahead of the compliance curve
Learn about new services that make it easy to discover and manage certificates across the enterprise and how to get ahead of the compliance curve.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.